Rivers & wetlands

Rivers, lakes, marshes and swamps store fresh water and pack in disproportionate biodiversity. Wetlands are also among the most rapidly disappearing habitats on Earth.

1163 animals in this habitat

Amphibians NE Clawed Frog Pipidae A clawed frog is a flat, fully aquatic frog with no tongue and small black claws on its hind feet, and the African clawed frog is one of the most studied animals in biology and a widespread invader. Read the guide →

Birds NE Crane Gruidae A crane is a tall wetland bird famous for leaping courtship dances, bugling calls that carry for kilometres, and migrations that take some species over the Himalayas at the height of a jet. Read the guide →

Fish NE Goby Gobiidae A goby is a small bottom-living fish whose pelvic fins are fused into a suction disc, and the family is among the largest of all vertebrate families, with well over 2,000 species. Read the guide →

Amphibians NE Mole Salamander Ambystomatidae A mole salamander is a stout burrowing amphibian of North America that spends most of the year underground and emerges on rainy nights to breed in temporary pools; the family includes the axolotl. Read the guide →

Reptiles NE Monitor Lizard Varanidae A monitor lizard is a big, active predator with a forked tongue, bird-like lungs, and rare stamina for a reptile; the group includes the Komodo dragon, the largest lizard alive. Read the guide →

Birds NE Swan Cygnus A swan is the largest and heaviest of the waterfowl, a long-necked grazer of underwater plants that pairs for years, defends its family fiercely, and in some species barely gets airborne at all. Read the guide →

Fish NE Trout Salmo, Oncorhynchus, and Salvelinus A trout is a cold-water fish of the salmon family, prized by anglers, farmed worldwide, and so widely stocked outside its home range that it now ranks among the most damaging of introduced fish. Read the guide →

Fish VU Carp Cyprinus carpio A carp is a hardy freshwater fish that roots through mud, shrugs off water that would kill most fish, and has been farmed for thousands of years while wrecking wetlands where it is introduced. Read the guide →

Reptiles NE Cobra Naja and relatives A cobra is a venomous snake that rears up and spreads a hood of loose neck skin as a warning, and several species can spray venom from the fangs straight at an attacker's eyes. Read the guide →

Mammals NE Deer Cervidae A deer is a hoofed browser whose males grow and shed a fresh set of branching antlers every year, the fastest normal bone growth known in any animal, then drop them and start again. Read the guide →

Amphibians CR Giant Salamander Cryptobranchidae A giant salamander is the largest amphibian alive, a wrinkled, flat-headed river dweller that breathes mostly through folds of loose skin and can pass a century in the same cold stream. Read the guide →

Birds NE Heron Ardeidae A heron is a long-legged wading bird that hunts by standing still in shallow water and then striking with a neck that unfolds like a spring, driving a dagger bill into fish, frogs, and voles. Read the guide →

Amphibians NE Horned Frog Ceratophryidae A horned frog is a South American ambush hunter that is almost all mouth, buries itself with only its eyes showing, and will lunge at and try to swallow prey nearly as large as itself. Read the guide →

Invertebrates NE Beetle Coleoptera A beetle is an insect with its front wings hardened into a case over its back, a design so durable that around one in every four named animal species on Earth is a kind of beetle. Read the guide →

Invertebrates NE Crab Brachyura A crab is a crustacean with a short, flattened, armoured body and a pair of pincers, a shape so useful that unrelated crustaceans have evolved into crab-like forms again and again. Read the guide →

Reptiles NE Python Pythonidae A python is a non-venomous constrictor that kills by stopping its prey's blood flow, swallows animals wider than its own head, and in one species grows longer than any other snake on Earth. Read the guide →

Fish NE Salmon Oncorhynchus and Salmo A salmon is a fish born in a river, grown in the sea, and driven back to the exact stream it hatched in to spawn, a trip that for most Pacific salmon ends in death within days. Read the guide →

Invertebrates NE Spider Araneae A spider is an eight-legged hunter that builds with silk, digests its prey outside its body, and in almost every species carries venom, though very few can seriously harm a person. Read the guide →

Amphibians NE Tadpole Anura A tadpole is the larva of a frog or toad, a legless, gilled swimmer that grazes on algae and then rebuilds its entire body, growing legs, absorbing its tail, and switching to breathing air. Read the guide →

Amphibians NE True Frog Ranidae A true frog is a member of the family Ranidae, the long-legged, smooth-skinned, powerful jumpers of pond and stream that most people picture first when they hear the word frog. Read the guide →

Reptiles NE Turtle Testudines A turtle is a reptile that carries its skeleton on the outside, a bony shell fused to its spine and ribs, a body plan so successful it has barely changed in over 200 million years. Read the guide →

Reptiles NE Crocodile Crocodylidae A crocodile is the largest reptile alive, an ambush predator whose lineage is older than the last dinosaurs, with the strongest bite ever measured and jaws that sense a single ripple on the water. Read the guide →

Fish NE Eel Anguilliformes An eel is a snake-shaped fish that begins life as a transparent, leaf-shaped larva, and the freshwater kinds grow for years in rivers before crossing the open ocean to spawn once and die. Read the guide →

Amphibians NE Frog Anura A frog is a tailless, jumping amphibian that starts life as a plant-eating tadpole in water, then becomes a meat-eating adult that breathes partly through its permeable skin. Read the guide →

Amphibians NE Salamander Caudata A salamander is a tailed, lizard-shaped amphibian with soft moist skin, and as a group salamanders are the best limb-regenerators among vertebrates, regrowing legs and tails without a scar. Read the guide →

Fish NE Catfish Siluriformes A catfish is one of a vast group of mostly bottom-living, scaleless fish that carry whiskery barbels, taste with their whole skin, and defend themselves with sharp locking fin spines. Read the guide →

Amphibians NE Newt Pleurodelinae A newt is a small salamander that returns to water each spring to breed, where the male grows a crest and courts by fanning pheromones with his tail; the young spend a land phase called an eft. Read the guide →

Reptiles LC Crocodile Monitor Varanus salvadorii The crocodile monitor is a huge tree-climbing lizard of New Guinea, often called the longest lizard in the world because more than half its length is a whip-like tail used for balance. Read the guide →

Birds LC Great Crested Grebe Podiceps cristatus The great crested grebe is a slender diving waterbird of open lakes, known for its head plumes, its elaborate courtship dances, and its striped chicks that ride on a parent's back. Read the guide →

Invertebrates NE Mole Cricket Gryllotalpidae The mole cricket is a burrowing cricket with wide, mole-like digging forelegs, and the male sings from a horn-shaped tunnel that works as a loudspeaker to carry his call across a field. Read the guide →

Fish NE Mudskipper Oxudercinae The mudskipper is an amphibious goby of tropical mangrove mudflats that spends low tide out of the water, breathing through its skin, walking on its front fins, and digging a burrow in the mud. Read the guide →

Amphibians CR Northern Corroboree Frog Pseudophryne pengilleyi The northern corroboree frog is a tiny yellow-and-black striped frog of Australian mountain bogs, one of the few animals that makes its own poison and one of the most endangered amphibians alive. Read the guide →

Invertebrates NE Damselfly Zygoptera The damselfly is the slender, weak-flying cousin of the dragonfly, resting with its wings folded along its body, and its larvae breathe through three leaf-like gills at the tail. Read the guide →

Fish LC Grayling Thymallus thymallus The grayling is a silver, thyme-scented river fish with an enormous sail-like fin, a member of the salmon family that lives only in cold, clean, fast water and is prized by winter fly-anglers. Read the guide →

Amphibians LC Jefferson Salamander Ambystoma jeffersonianum The Jefferson salamander is a slender mole salamander of eastern North American woods that breeds in icy vernal pools in late winter, and its ponds hold an ancient all-female salamander lineage. Read the guide →

Fish LC Roach Rutilus rutilus The roach is a silvery, red-finned carp relative, probably the commonest freshwater fish across much of Europe, and the fish generations of anglers have caught first. Read the guide →

Invertebrates NE Dragonfly Anisoptera The dragonfly is a hunting insect with four independent wings and one of the highest kill rates of any predator, whose young spend months or years underwater before weeks in the air. Read the guide →

Fish LC European Perch Perca fluviatilis The European perch is a striped, spiny-finned predator of lakes and slow rivers across Europe and northern Asia that shoals when young and turns to solitary ambush hunting when old. Read the guide →

Amphibians LC European Tree Frog Hyla arborea The European tree frog is a small, bright green climbing frog of mainland Europe that spends warm days basking on leaves and fills spring nights with a loud rasping chorus. Read the guide →

Fish LC Three-spined Stickleback Gasterosteus aculeatus The three-spined stickleback is a tiny armoured fish of northern waters whose courting male turns red-throated, builds a glued tunnel nest, and is a leading model for studying evolution. Read the guide →

Fish LC Brook Trout Salvelinus fontinalis The brook trout is a marbled, red-spotted fish of cold, clean streams in eastern North America that is really a char, an emblem of unspoilt water that vanishes when its streams warm or silt up. Read the guide →

Invertebrates NE Crayfish Astacoidea and Parastacoidea Crayfish are freshwater crustaceans that look like small lobsters, found on every continent but Africa and Antarctica, digging burrows and carrying their young in a cluster under the tail. Read the guide →

Reptiles LC Grass Snake Natrix natrix The grass snake is the largest and commonest snake in Britain, a harmless olive-green swimmer that hunts frogs and toads, lays eggs in compost heaps, and plays dead when threatened. Read the guide →

Amphibians LC Palmate Newt Lissotriton helveticus The palmate newt is the smallest newt in Britain and western Europe, a delicate amphibian whose breeding male grows black webs on his hind feet and a fine thread off the tip of his tail. Read the guide →

Amphibians LC Cope's Gray Treefrog Hyla chrysoscelis Cope's gray treefrog is a warty, colour-changing tree frog of the eastern United States, a look-alike of the common gray treefrog told apart only by its faster call and its chromosome count. Read the guide →

Fish LC Tench Tinca tinca The tench is a thick, olive-gold European carp relative coated in heavy slime, a bottom feeder of muddy still waters that folklore once claimed could heal other fish that rubbed against it. Read the guide →

Amphibians VU Tennessee Cave Salamander Gyrinophilus palleucus The Tennessee cave salamander is a pale, big-gilled amphibian that spends its whole life as a larva in the black streams of a few hundred caves, never leaving the water and never growing up. Read the guide →

Birds LC Trumpeter Swan Cygnus buccinator The trumpeter swan is the heaviest waterfowl native to North America, a white bird with a brassy bugling call, hunted down to a few dozen birds by the 1930s and since recovered past 60,000. Read the guide →

Amphibians LC Two-lined Salamander Eurycea bislineata The two-lined salamander is a slim yellow-brown brook salamander of eastern North America with a dark stripe down each side, a night hunter of stream edges that breathes through its skin. Read the guide →

Fish LC Barbel Barbus barbus The barbel is a powerful, torpedo-shaped river fish of fast, gravelly water, with four whisker-like barbels around its mouth that it uses to find food on the bottom, and a poisonous roe. Read the guide →

Fish LC Bleak Alburnus alburnus The bleak is a slender, silvery surface-shoaling fish of European rivers and lakes whose scales were once used to make the shimmering coating of artificial pearls. Read the guide →

Fish LC Brook Lamprey Lampetra planeri The brook lamprey is a small, eel-like freshwater lamprey that spends years as a blind, silt-dwelling larva, then transforms, spawns in gravel, and dies without ever feeding as an adult. Read the guide →

Fish LC Chain Pickerel Esox niger The chain pickerel is the small pike of eastern North America, a slim green ambush fish marked with a dark chain-link pattern that explodes from weed cover onto passing prey. Read the guide →

Fish LC Chub Squalius cephalus The chub is a wary, thick-bodied river fish with a broad head and big mouth that eats almost anything, from insects and crayfish to small fish and berries that fall into the water. Read the guide →

Fish LC Common Bream Abramis brama The common bream is a deep, slab-sided, bronze fish that grubs for worms and snails on the bottom of slow rivers and lakes in large shoals, and is one of the most abundant fish of northern Europe. Read the guide →

Fish LC Common Dace Leuciscus leuciscus The common dace is a slender, silvery shoaling fish of fast, clear rivers that rises to catch flies at the surface, and is one of the quickest and liveliest of the European carp family. Read the guide →

Fish LC Common Minnow Phoxinus phoxinus The common minnow is a tiny, shoaling stream fish whose breeding males flush red and black, and whose damaged skin releases an alarm chemical that sends its whole shoal fleeing. Read the guide →

Fish LC Crucian Carp Carassius carassius The crucian carp is a deep, golden, barbel-less pond fish that survives for months without oxygen under winter ice and grows a deeper body when pike are around. Read the guide →

Fish LC European Bitterling Rhodeus amarus The European bitterling is a tiny, iridescent carp relative whose female lays her eggs inside the gills of a living freshwater mussel, which then shelters the young fish while they grow. Read the guide →

Fish LC European Bullhead Cottus gobio The European bullhead, or miller's thumb, is a flat-headed, big-mouthed little fish that lurks under stones in clear streams, ambushing invertebrates, and whose male guards the eggs in his rocky nest. Read the guide →

Fish LC European Smelt Osmerus eperlanus The European smelt, or sparling, is a slender, silvery fish of estuaries and coasts that smells strongly of cucumber, runs up rivers to spawn in spring, and is prey for many larger fish and birds. Read the guide →

Fish LC Flathead Catfish Pylodictis olivaris The flathead catfish is a huge, flat-headed river catfish with a jutting lower jaw and mottled gold skin, a solitary night hunter that eats live fish and can pass 45 kg in its native waters. Read the guide →

Invertebrates NE Freshwater Jellyfish Craspedacusta sowerbii The freshwater jellyfish is a tiny, coin-sized, harmless jellyfish from China that has spread worldwide and appears in lakes and quarries in sudden summer blooms. Read the guide →

Invertebrates EN Freshwater Pearl Mussel Margaritifera margaritifera The freshwater pearl mussel is a dark, long-lived river mussel that can survive for well over a century, whose larvae live on salmon and trout gills, and which is now endangered across Europe. Read the guide →

Invertebrates NE Freshwater Shrimp Gammarus pulex The freshwater shrimp is a small, sideways-flattened, leaf-shredding crustacean of clean European streams that swims on its side, carries its mate before pairing, and signals good water quality. Read the guide →

Reptiles CR Golden Coin Turtle Cuora trifasciata The golden coin turtle is a small box turtle with three dark stripes on a golden-brown shell, so prized in traditional medicine that it is among the world's most valuable and threatened turtles. Read the guide →

Invertebrates LC Great Pond Snail Lymnaea stagnalis The great pond snail is a large, air-breathing freshwater snail of European and northern ponds that glides upside down along the water surface and is a model animal for studying memory. Read the guide →

Invertebrates NE Great Silver Water Beetle Hydrophilus piceus The great silver water beetle is a glossy black giant among European water beetles that carries a silvery film of air, grazes water plants as an adult, and floats its eggs in a silk case with a mast. Read the guide →

Invertebrates NE Green Drake Mayfly Ephemera danica The green drake is a large, cream-and-grey European mayfly whose burrowing nymphs live in river silt for one or two years, before adults hatch in a spectacular emergence and live only a day or two. Read the guide →

Fish LC Gudgeon Gobio gobio The gudgeon is a small, speckled bottom-dwelling fish with a pair of sensitive barbels at the corners of its mouth, found in shoals over sand and gravel in rivers and lakes across Europe. Read the guide →

Fish EN Huchen Hucho hucho The huchen, or Danube salmon, is a huge, torpedo-shaped predator of clean, cold Danube rivers, one of the largest salmon relatives in the world and now endangered by dams and pollution. Read the guide →

Fish LC Ide Leuciscus idus The ide, or orfe, is a deep-bodied, silvery shoaling fish of northern and eastern European rivers and lakes whose golden form, the golden orfe, is a favourite of garden ponds. Read the guide →

Fish LC Longear Sunfish Lepomis megalotis The longear sunfish is a palm-sized freshwater fish of clear American streams, its turquoise-and-orange body marked with wavy blue face lines and a long black ear flap edged in white. Read the guide →

Birds LC Mandarin Duck Aix galericulata The mandarin duck is a small East Asian perching duck whose drake wears orange sail-feathers and a purple breast, nests in tree holes, and has become a naturalised bird of British parks. Read the guide →

Reptiles VU Mugger Crocodile Crocodylus palustris The mugger is a broad-snouted South Asian crocodile of marshes and village reservoirs, a burrow-digging predator up to about 4 metres that has recovered in India after decades of hide hunting. Read the guide →

Reptiles CR Northern River Terrapin Batagur baska The northern river terrapin is one of Asia's largest freshwater turtles, a plant-eating giant of estuaries and tidal rivers that nests on sandbanks and is Critically Endangered. Read the guide →

Invertebrates LC Painter's Mussel Unio pictorum The painter's mussel is an elongated freshwater mussel of European rivers and lakes whose shells were once used by artists to hold their pigments, and whose larvae travel on the gills of fish. Read the guide →

Invertebrates NE Quagga Mussel Dreissena rostriformis bugensis The quagga mussel is a small, striped freshwater mussel from Ukraine that has invaded the Great Lakes and western Europe, carpeting the bottom, clogging pipes, and outcompeting the zebra mussel. Read the guide →

Fish LC River Lamprey Lampetra fluviatilis The river lamprey is a jawless, eel-like fish that lives as a larva in river silt, feeds on other fish in estuaries as a parasite, and returns to rivers to spawn in autumn and spring before dying. Read the guide →

Reptiles CR Roti Island Snake-necked Turtle Chelodina mccordi The Roti Island snake-necked turtle is a freshwater turtle with an extraordinarily long neck, found naturally only on one small Indonesian island and nearly wiped out by collecting for the pet trade. Read the guide →

Fish LC Rudd Scardinius erythrophthalmus The rudd is a golden-bronze carp relative with blazing red fins and an upturned mouth, a surface-feeding fish of still and slow waters across Europe that readily hybridises with roach and bream. Read the guide →

Fish LC Ruffe Gymnocephalus cernua The ruffe is a small, spiny perch relative of European lakes and rivers with a single prickly dorsal fin and sensory pits on its head, and a successful invader in the Great Lakes of North America. Read the guide →

Invertebrates LC Signal Crayfish Pacifastacus leniusculus The signal crayfish is a large, bold North American crayfish with a pale patch on each claw that was introduced to Europe for farming and is now an invader that carries plague to native crayfish. Read the guide →

Fish LC Silver Bream Blicca bjoerkna The silver bream, or white bream, is a small, deep-bodied, silvery shoaling fish of slow European rivers and lakes that resembles a young common bream but has larger eyes and pinkish fins. Read the guide →

Fish LC Spined Loach Cobitis taenia The spined loach is a slim, sand-dwelling little fish with a hidden spine below each eye and six barbels, which buries itself by day and sifts the bottom for food by night. Read the guide →

Fish LC Stone Loach Barbatula barbatula The stone loach is a slender, mottled, nocturnal bottom fish with six whisker-like barbels, which hides under stones by day in clean streams and rivers across Europe and Asia. Read the guide →

Fish LC Sunbleak Leucaspius delineatus The sunbleak is a tiny, silvery European shoaling fish with an upturned mouth whose male guards a spiral string of eggs wrapped around a reed stem, and which has become an invader in Britain. Read the guide →

Invertebrates LC Swan Mussel Anodonta cygnea The swan mussel is a large, thin-shelled freshwater mussel of European lakes and slow rivers that ploughs a trail through the mud, filters the water, and sends its larvae to hitch a ride on fish. Read the guide →

Fish LC Topmouth Gudgeon Pseudorasbora parva The topmouth gudgeon is a tiny, hardy East Asian carp relative that was accidentally introduced to Europe in the 1960s and is now a widespread invader that carries a parasite harmful to native fish. Read the guide →

Fish LC Vimba Bream Vimba vimba The vimba bream is a slender, silvery carp relative with a pointed, overhanging snout that feeds on the bottom of rivers and estuaries and runs upstream to spawn on gravel. Read the guide →

Invertebrates NE Water Louse Asellus aquaticus The water louse is a flat, grey-brown aquatic relative of the woodlouse that crawls over mud and weed in ponds and slow rivers, feeds on rotting plant matter, and tolerates poor water. Read the guide →

Invertebrates EN White-clawed Crayfish Austropotamobius pallipes The white-clawed crayfish is Britain's only native freshwater crayfish, a small nocturnal inhabitant of clean, hard-water streams that is endangered by plague carried by invading American crayfish. Read the guide →

Amphibians EW Wyoming Toad Anaxyrus baxteri The Wyoming toad is a small high-plains toad from one Wyoming valley, declared extinct in the wild in the 1990s and now kept alive by zoos that breed thousands of tadpoles a year for release. Read the guide →

Fish LC Zander Sander lucioperca The zander, or pikeperch, is a large, pale-eyed predator of murky European lakes and rivers with fangs like a pike and the spiny fin of a perch, prized as food and widely introduced. Read the guide →

Reptiles CR Bog Turtle Glyptemys muhlenbergii The bog turtle is North America's smallest turtle, a palm-sized species with an orange neck blaze, now one of the continent's most endangered, clinging to scattered spring-fed bogs. Read the guide →

Reptiles LC Eastern Kingsnake Lampropeltis getula The eastern kingsnake is a powerful constrictor that hunts and eats other snakes, rattlesnakes and copperheads included, and shrugs off a dose of their venom that would kill most animals. Read the guide →

Fish LC Walking Catfish Clarias batrachus The walking catfish breathes air, survives out of water for hours, and crosses wet ground between ponds by wriggling on its stiff fins, which has made it a fast-spreading invader in Florida. Read the guide →

Fish LC Yellow Perch Perca flavescens The yellow perch is a golden, tiger-striped panfish of North American lakes, one of the most sought-after fish for eating and ice fishing, and a favourite prey of walleye, pike, and bass. Read the guide →

Reptiles LC Common Musk Turtle Sternotherus odoratus The common musk turtle, or stinkpot, is a tiny bottom-walker that climbs high into streamside trees, sometimes dropping into a boat, and releases a foul musk when it is handled. Read the guide →

Amphibians LC Shovel-nosed Salamander Desmognathus marmoratus The shovel-nosed salamander never leaves the water, living its whole life wedged under stones in cold Appalachian torrents and digging through the gravel with a flattened, spade-like snout. Read the guide →

Amphibians LC Tailed Frog Ascaphus truei The tailed frog is one of the most primitive frogs alive and the only North American frog with internal fertilisation, and its tadpoles grip rocks in freezing torrents with a sucker mouth. Read the guide →

Invertebrates LC Azure Damselfly Coenagrion puella The azure damselfly is a slender sky-blue damselfly with black markings, one of the most abundant damselflies of ponds and ditches, told from its relatives by a black U-shaped mark. Read the guide →

Mammals EN Baird's Tapir Tapirus bairdii Baird's tapir is the largest land mammal of Central America, an Endangered swimmer and seed disperser of tropical forests and wetlands from southern Mexico to northern Colombia. Read the guide →

Invertebrates LC Banded Demoiselle Calopteryx splendens The banded demoiselle is a metallic blue damselfly of slow rivers whose male has a broad dark band across each wing and flutters through the air like a butterfly. Read the guide →

Reptiles LC Banded Krait Bungarus fasciatus The banded krait is a boldly striped black-and-yellow snake of South and Southeast Asia that hunts other snakes at night, with a deadly neurotoxic venom but a placid nature by day. Read the guide →

Invertebrates LC Beautiful Demoiselle Calopteryx virgo The beautiful demoiselle is a damselfly of fast, clean streams whose male has deep violet-blue wings and body, and whose presence is a sign of good water quality. Read the guide →

Amphibians LC Black-bellied Salamander Desmognathus quadramaculatus The black-bellied salamander is the biggest Appalachian stream salamander, a heavy, aggressive lungless hunter that takes insects, crayfish, and even other salamanders in fast mountain water. Read the guide →

Invertebrates LC Black-tailed Skimmer Orthetrum cancellatum The black-tailed skimmer is a dragonfly whose mature male has a powder-blue abdomen ending in a black tip, basking on bare ground beside gravel pits, ponds, and slow rivers. Read the guide →

Invertebrates LC Blue-tailed Damselfly Ischnura elegans The blue-tailed damselfly is a slender black damselfly with a single bright blue segment at the tip of the tail, tolerant of small and polluted waters and found around ponds and ditches. Read the guide →

Invertebrates LC Broad-bodied Chaser Libellula depressa The broad-bodied chaser is a stocky, flat-bodied dragonfly whose male is dusted pale blue, and one of the first species to colonise new garden ponds. Read the guide →

Reptiles LC Broad-snouted Caiman Caiman latirostris The broad-snouted caiman is a South American crocodilian with a wide, short snout suited to crushing snails, and one of the species managed by a sustainable ranching programme in Argentina. Read the guide →

Invertebrates LC Brown Hawker Aeshna grandis The brown hawker is a large dragonfly with a rich brown body and amber-tinted wings that glow golden in the sun, patrolling ponds and canals from midsummer into autumn. Read the guide →

Birds LC Cattle Egret Bubulcus ibis The cattle egret is a small white heron that followed grazing herds out of Africa, crossed the Atlantic on its own around 1877, and now trails cattle and tractors across most of the world. Read the guide →

Invertebrates LC Common Blue Damselfly Enallagma cyathigerum The common blue damselfly is a bright blue damselfly of lakes and ponds across the Northern Hemisphere, recognised by a mushroom-shaped black mark near the base of the abdomen. Read the guide →

Invertebrates LC Common Darter Sympetrum striolatum The common darter is a small dragonfly whose male turns orange-red, a late-season species that darts out from a perch to catch prey and is often the last dragonfly on the wing in autumn. Read the guide →

Mammals LC Cuban Hutia Capromys pilorides The Cuban hutia is a stocky, tree-climbing rodent of Cuba and nearby islands, one of the largest surviving hutias and a rare native mammal of the Caribbean. Read the guide →

Reptiles LC Cuvier's Dwarf Caiman Paleosuchus palpebrosus Cuvier's dwarf caiman is the smallest crocodilian, a heavily armoured, shy caiman of South American forest streams that grows to little more than a metre and a half. Read the guide →

Mammals LC Daubenton's Bat Myotis daubentonii Daubenton's bat is the water bat, skimming just above lakes and rivers to scoop insects off the surface with its large feet and tail membrane. Read the guide →

Fish CR Devils Hole Pupfish Cyprinodon diabolis The Devils Hole pupfish lives in one sunlit desert pool in Nevada, the smallest natural range of any vertebrate, and its survival once hinged on a US Supreme Court ruling about groundwater. Read the guide →

Reptiles LC Dice Snake Natrix tessellata The dice snake is a non-venomous semi-aquatic snake of rivers and lakes in Europe and Asia, with a chequered pattern like dice, that hunts fish underwater and plays dead when threatened. Read the guide →

Reptiles LC Eastern Long-necked Turtle Chelodina longicollis The eastern long-necked turtle is an Australian freshwater turtle with a neck as long as its shell that sucks in prey in a flash, smells foul when handled, and walks overland between wetlands. Read the guide →

Reptiles LC Eastern Water Dragon Intellagama lesueurii The eastern water dragon is a large Australian lizard of rivers and parks, a strong swimmer that dives to escape danger, with orange-chested males and eggs whose sex depends on temperature. Read the guide →

Reptiles NT European Pond Turtle Emys orbicularis The European pond turtle is a long-lived freshwater turtle with a dark, yellow-speckled shell, found in ponds and marshes across Europe, and threatened by habitat loss and invasive sliders. Read the guide →

Mammals EN Flat-headed Cat Prionailurus planiceps The flat-headed cat is a semi-aquatic Southeast Asian hunter with a long, flattened skull and fish-gripping teeth, one of the few cats that seeks out wetlands for its prey. Read the guide →

Reptiles LC Forest Cobra Naja melanoleuca The forest cobra is Africa's largest true cobra, a glossy black, swimming and tree-climbing snake of rainforest and wet savanna that hunts fish, amphibians, and snakes with a neurotoxic venom. Read the guide →

Reptiles LC Freshwater Crocodile Crocodylus johnstoni The freshwater crocodile, or freshie, is a slender-snouted Australian crocodile of northern rivers that eats fish and insects, is far shyer than the saltwater crocodile, and was hit by cane toads. Read the guide →

Invertebrates LC Golden-ringed Dragonfly Cordulegaster boltonii The golden-ringed dragonfly is a huge black dragonfly with yellow rings and green eyes, whose female stabs her eggs into the mud of upland streams with a long ovipositor. Read the guide →

Reptiles NT Indian Rock Python Python molurus The Indian rock python is a heavy, pale-blotched constrictor of South Asia whose brooding mother shivers to warm her eggs, and which has declined as its grassland and marsh habitats have been lost. Read the guide →

Mammals LC Jungle Cat Felis chaus The jungle cat is a long-legged, plain-coated wild cat that thrives in reed beds and wetlands from Egypt to Southeast Asia, and was once mummified in ancient Egypt. Read the guide →

Invertebrates LC Large Red Damselfly Pyrrhosoma nymphula The large red damselfly is the first damselfly of spring, a slender red-and-black insect that emerges in April and May around ponds, ditches, and slow streams. Read the guide →

Reptiles LC Lowland Copperhead Austrelaps superbus The lowland copperhead is a shy, cold-tolerant Australian snake of southern swamps and grassland with coppery flanks, no relation to the American copperhead, that gives birth to live young. Read the guide →

Mammals LC Meadow Jumping Mouse Zapus hudsonius The meadow jumping mouse leaps on long hind legs with a tail longer than its body, and hibernates through most of the year in damp North American meadows. Read the guide →

Amphibians LC Mink Frog Lithobates septentrionalis The mink frog is a small green frog of cold northern lakes that smells of rotten onions or mink when handled, and whose call sounds like a stick tapped fast against a hollow log. Read the guide →

Reptiles LC Monocled Cobra Naja kaouthia The monocled cobra is a brown-to-olive cobra of South and Southeast Asia, marked by a single ring on the back of its hood, that lives in wetlands and paddies and whose bite can destroy tissue. Read the guide →

Reptiles LC Morelet's Crocodile Crocodylus moreletii Morelet's crocodile is a medium-sized freshwater crocodile of Mexico, Belize, and Guatemala that recovered after heavy hunting for its skin and is now classed as Least Concern. Read the guide →

Mammals LC Nathusius's Pipistrelle Pipistrellus nathusii Nathusius's pipistrelle is a small European bat that makes one of the longest migrations of any bat, flying more than two thousand kilometres between northeastern and southwestern Europe. Read the guide →

Reptiles LC New Guinea Crocodile Crocodylus novaeguineae The New Guinea crocodile is a dark, medium-sized freshwater crocodile of the swamps, rivers, and lakes of New Guinea, and the close relative of the rare Philippine crocodile. Read the guide →

Invertebrates LC Old World Swallowtail Papilio machaon The Old World swallowtail is a large yellow-and-black butterfly whose green caterpillar rears a smelly orange horn when threatened, and whose British form lives only in the Norfolk Broads. Read the guide →

Reptiles CR Orinoco Crocodile Crocodylus intermedius The Orinoco crocodile is a large, slender-snouted crocodile of the Orinoco river basin in Colombia and Venezuela, hunted almost to extinction for its skin and now Critically Endangered. Read the guide →

Reptiles CR Philippine Crocodile Crocodylus mindorensis The Philippine crocodile is a small freshwater crocodile found only in the Philippines, one of the rarest crocodilians on Earth, protected by villagers who are rewarded for guarding nests. Read the guide →

Invertebrates NE Puss Moth Cerura vinula The puss moth is a fluffy white-and-grey European moth whose green caterpillar rears up with a red false face and whip-like tails and sprays formic acid at attackers. Read the guide →

Mammals LC Rakali Hydromys chrysogaster The rakali is Australia's semi-aquatic native water-rat, a white-tailed hunter of freshwater crayfish, mussels, and fish that is at home in rivers, lakes, and estuaries. Read the guide →

Reptiles LC Red-bellied Black Snake Pseudechis porphyriacus The red-bellied black snake is a glossy, shy Australian snake with bright red flanks and belly that swims well, eats frogs and other snakes, and has evolved some resistance to cane toad toxin. Read the guide →

Amphibians LC River Frog Lithobates heckscheri The river frog is a big, dark, wrinkly frog of southeastern swamps and blackwater rivers, named for a deep snoring growl and known for playing dead when it is picked up. Read the guide →

Reptiles CR Siamese Crocodile Crocodylus siamensis The Siamese crocodile is a medium-sized freshwater crocodile of Southeast Asia, once widespread and now Critically Endangered, with tiny wild populations kept alive by protection and breeding. Read the guide →

Reptiles CR Slender-snouted Crocodile Mecistops cataphractus The slender-snouted crocodile is a shy, narrow-snouted fish-eater of West and Central African rivers and forest swamps, now Critically Endangered through hunting for bushmeat and loss of habitat. Read the guide →

Reptiles LC Smooth-fronted Caiman Paleosuchus trigonatus The smooth-fronted caiman is a dark, heavily armoured dwarf caiman of Amazon forest streams, a bit larger than Cuvier's dwarf caiman, with a smooth forehead and forest-floor nest mounds. Read the guide →

Mammals LC Soprano Pipistrelle Pipistrellus pygmaeus The soprano pipistrelle is a tiny European bat named for its higher-pitched calls, once lumped with the common pipistrelle, that hunts over rivers and lakes and roosts in large summer colonies. Read the guide →

Invertebrates LC Southern Hawker Aeshna cyanea The southern hawker is a large, inquisitive dragonfly with apple-green and blue markings that hunts along woodland paths and garden hedges and will hover to inspect passing people. Read the guide →

Mammals VU Sulawesi Babirusa Babyrousa celebensis The Sulawesi babirusa is a Vulnerable wild pig whose upper tusks grow up through its snout and curve back toward its forehead, found only on the Indonesian island of Sulawesi. Read the guide →

Reptiles LC Tiger Snake Notechis scutatus The tiger snake is a highly venomous Australian snake of southern wetlands, often banded like a tiger, that flattens its neck when threatened and gives birth to live young. Read the guide →

Reptiles LC Water Python Liasis fuscus The water python is a brown, iridescent-scaled Australian python of northern floodplains and billabongs that hunts rats, birds, and reptiles at night and reaches around three metres in length. Read the guide →

Reptiles CR Western Swamp Turtle Pseudemydura umbrina The western swamp turtle is a tiny, brown freshwater turtle found only in a few seasonal swamps near Perth, Australia's most endangered reptile, saved from the brink by captive breeding. Read the guide →

Reptiles LC Yacare Caiman Caiman yacare The yacare caiman is a medium-sized crocodilian of the Pantanal and surrounding wetlands, where millions live, fish for piranha, and gather in dense groups in the shrinking pools of the dry season. Read the guide →

Reptiles CR Big-headed Turtle Platysternon megacephalum The big-headed turtle of Asian mountain streams has a head too big to pull into its shell, so it is armoured instead, and the turtle climbs rocks and trees using its long tail as a brace. Read the guide →

Invertebrates NE Horsehair Worm Nematomorpha The horsehair worm is a hair-thin parasite up to a metre long that grows inside a cricket, then hijacks its brain and drives the insect to drown itself so the worm can escape into water. Read the guide →

Fish LC White Sturgeon Acipenser transmontanus The white sturgeon is the largest freshwater fish in North America, an armoured survivor from the age of dinosaurs that can pass 6 metres, weigh over 800 kg, and live more than a century. Read the guide →

Birds LC American Bittern Botaurus lentiginosus The American bittern is a heron that hides in the reeds by freezing with its bill pointed straight up, and whose deep pumping boom carries across a marsh at dusk. Read the guide →

Invertebrates NE Crane Fly Tipulidae The crane fly is the giant, long-legged insect often called a mosquito hawk, though it does not hunt mosquitoes or bite anyone, and most adults do not feed at all before they die. Read the guide →

Amphibians CR Dusky Gopher Frog Lithobates sevosus The dusky gopher frog is one of the world's most endangered amphibians, a warty Mississippi frog that lives in gopher tortoise burrows and hides its eyes behind its hands when frightened. Read the guide →

Fish LC Freshwater Drum Aplodinotus grunniens The freshwater drum is the only croaker that lives entirely in fresh water, a bottom fish that grunts, crushes snails with its throat, and leaves behind lucky-stone ear bones. Read the guide →

Reptiles LC Northern Water Snake Nerodia sipedon The northern water snake is a harmless fish-eating snake of North American ponds and rivers that is killed on sight across its range because it is mistaken for a venomous cottonmouth. Read the guide →

Reptiles EN Wood Turtle Glyptemys insculpta The wood turtle has a shell that looks carved from wood, does well in maze and learning tests, and stomps the ground with its feet to bring earthworms to the surface. Read the guide →

Birds LC American Dipper Cinclus mexicanus The American dipper is the only songbird in North America that swims, walking along the beds of fast mountain streams and diving underwater to hunt insect larvae year-round. Read the guide →

Fish LC Bigmouth Buffalo Ictiobus cyprinellus The bigmouth buffalo is North America's largest sucker, often mistaken for a carp, and a fish that turned out to live longer than any other, with some individuals over 110 years old. Read the guide →

Birds LC Green Heron Butorides virescens The green heron is a small, stocky heron of the Americas and one of the few birds that uses tools, dropping insects, feathers, or bread onto the water to lure fish within reach. Read the guide →

Amphibians LC Little Grass Frog Pseudacris ocularis The little grass frog is the smallest frog in North America, under 2 cm long, a tan wetland-edge chorus frog whose thin tinkling call is often mistaken for an insect. Read the guide →

Fish NT Silver Carp Hypophthalmichthys molitrix The silver carp is an Asian filter-feeding fish that has overrun the Mississippi basin and is infamous for hurling its heavy body clear of the water when startled by a boat motor. Read the guide →

Amphibians LC Spring Salamander Gyrinophilus porphyriticus The spring salamander is a large pink lungless salamander of cold Appalachian streams that breathes through its skin and hunts other salamanders, including its own kind. Read the guide →

Invertebrates NE Alderfly Sialidae The alderfly's predatory larva breathes through feathery gills in clean streams and ponds, while the short-lived adult barely feeds at all before dying within days. Read the guide →

Fish NE Angelicus Catfish Synodontis angelicus The angelicus catfish is covered in bold white spots against a dark body, often swimming upside down to graze food from the underside of logs and leaves. Read the guide →

Invertebrates NE Assassin Snail Clea helena The assassin snail hunts and eats other snails, often kept deliberately in aquariums to control outbreaks of smaller pest snail species that reproduce out of control. Read the guide →

Amphibians LC Barking Tree Frog Dryophytes gratiosus The barking tree frog is the largest tree frog native to the US, a plump spotted climber of southern pinewoods that barks like a dog from the treetops and digs into sand in dry spells. Read the guide →

Birds LC Belted Kingfisher Megaceryle alcyon The belted kingfisher patrols North American rivers with a loud rattle, dives headfirst for fish, nests in a tunnel in an earth bank, and has a female more colourful than the male. Read the guide →

Fish NE Black Ghost Knifefish Apteronotus albifrons The black ghost knifefish swims entirely backward and forward with a single rippling fin, generating a weak electric field around its body to navigate and hunt in total darkness. Read the guide →

Fish EN Boesemani Rainbowfish Melanotaenia boesemani The boesemani rainbowfish shows a sharp colour split along its body, blue-grey at the front and vivid orange-yellow at the back, native to only one small lake system in Indonesia. Read the guide →

Fish NE Bristlenose Pleco Ancistrus cirrhosus The bristlenose pleco stays far smaller than giant pleco relatives, making it a practical algae-eating catfish for home aquariums, with males growing fleshy tentacles on the face. Read the guide →

Fish LC Burbot Lota lota The burbot is the only member of the cod family that lives in fresh water, a mottled, barbel-chinned predator of cold northern lakes that spawns in a writhing ball under midwinter ice. Read the guide →

Fish LC Cardinal Tetra Paracheirodon axelrodi The cardinal tetra carries a brilliant blue-red stripe running the entire length of its body, a small schooling fish from the Amazon's blackwater rivers popular in home aquariums worldwide. Read the guide →

Fish LC Celebes Rainbowfish Marosatherina ladigesi The celebes rainbowfish carries unusually elongated, flag-like fins for its small size, native to a limited area of Sulawesi, Indonesia, and distinct enough to sit in its own genus. Read the guide →

Invertebrates NE Cherry Shrimp Neocaridina davidi The cherry shrimp has been selectively bred into a deep, solid red colour from a naturally plainer wild form, now one of the most popular small shrimp kept in freshwater aquariums. Read the guide →

Fish NE Croaking Gourami Trichopsis vittata The croaking gourami produces an audible croaking sound by vibrating muscles against its pectoral fins, one of the few aquarium fish whose courtship and territorial displays can actually be heard. Read the guide →

Invertebrates LC Emperor Dragonfly Anax imperator The emperor dragonfly is one of the largest and fastest dragonfly species in Europe, patrolling ponds in powerful, continuous flight while hunting other flying insects out of the air. Read the guide →

Fish EN Endler's Livebearer Poecilia wingei Endler's livebearer is naturally restricted to just a couple of small lagoons in Venezuela, a vividly coloured relative of the guppy now far more common in aquariums than in the wild. Read the guide →

Fish NE Figure-8 Puffer Dichotomyctere ocellatus The figure-8 puffer carries a pattern of interlocking loops on its back resembling the numeral eight, a small brackish-water pufferfish that inflates sharply when threatened. Read the guide →

Fish NE Flowerhorn Cichlid Hybrid cichlid, no single wild species The flowerhorn cichlid is a man-made hybrid fish that does not exist in the wild, bred for a prominent head bump and vivid colours that some cultures consider symbols of good fortune. Read the guide →

Fish LC Frontosa Cichlid Cyphotilapia frontosa The frontosa cichlid develops a prominent fatty bump on its forehead as it matures, growing larger and more pronounced with age in one of Lake Tanganyika's largest and longest-lived cichlids. Read the guide →

Fish LC Giant Gourami Osphronemus goramy The giant gourami grows up to 70 centimetres, far larger than its small, popular aquarium relatives, and serves as a major farmed food fish across Southeast Asia. Read the guide →

Invertebrates LC Great Diving Beetle Dytiscus marginalis The great diving beetle is one of the fiercest hunters in a European pond, an air-carrying underwater predator of tadpoles and small fish whose larva, the water tiger, sucks its prey dry. Read the guide →

Fish LC Lake Sturgeon Acipenser fulvescens The lake sturgeon is a bony-plated living fossil of North American lakes that can live past 100 years, was nearly wiped out for its caviar and isinglass, and is recovering only slowly. Read the guide →

Amphibians LC Marsh Frog Pelophylax ridibundus The marsh frog is the largest frog native to Europe, a big green water frog whose loud cackling chorus earns it the name laughing frog, and a parent species of the hybrid edible frog. Read the guide →

Reptiles LC Massasauga Sistrurus catenatus The massasauga is a small, shy wetland rattlesnake of the North American interior with a buzz more like an insect than a rattle, and the eastern population is now federally threatened. Read the guide →

Fish NT Medaka Oryzias latipes The medaka was the first fish ever bred successfully in space, a small, hardy Japanese species that has become one of the most important model organisms in genetics research. Read the guide →

Fish NE Moonlight Gourami Trichopodus microlepis The moonlight gourami carries a pale, silvery-green body with a faint glowing quality, making it one of the more subtly elegant gouramis kept in home aquariums. Read the guide →

Invertebrates NE Mystery Snail Pomacea bridgesii The mystery snail breathes with both gills and a lung, letting it live underwater or crawl out briefly to gulp air, a large, peaceful algae-grazer popular in home aquariums. Read the guide →

Fish EN Rainbow Shark Epalzeorhynchos frenatum The rainbow shark is not a true shark but a shark-shaped freshwater minnow, now considered Endangered in the wild in Thailand despite remaining common and widely bred for aquariums. Read the guide →

Invertebrates NE Ramshorn Snail Planorbella and relatives The ramshorn snail carries a flattened, coiled shell resembling a ram's horn, breathing air through a simple lung that lets it survive in low-oxygen water where many snails cannot. Read the guide →

Fish CR Redtail Shark Epalzeorhynchos bicolor The redtail shark was believed extinct in the wild for decades, surviving only in aquariums worldwide, until a small wild population was eventually rediscovered in Thailand. Read the guide →

Fish LC Snakeskin Gourami Trichopodus pectoralis The snakeskin gourami carries a mottled, scale-like pattern across its body resembling snake skin, and ranks among the more commercially important farmed gouramis of Southeast Asia. Read the guide →

Fish VU Turquoise Rainbowfish Melanotaenia lacustris The turquoise rainbowfish shows a vivid blue-green body found naturally only in a single lake in Papua New Guinea, a restricted range that leaves its wild population vulnerable to any change there. Read the guide →

Invertebrates NE Vampire Shrimp Atyopsis moluccensis The vampire shrimp catches food by holding out a pair of fan-shaped appendages to filter tiny particles directly from the current, rather than scavenging the substrate like most shrimp. Read the guide →

Mammals EN Web-footed Tenrec Limnogale mergulus The web-footed tenrec traded the spiny coat of its relatives for dense, waterproof fur, becoming the only tenrec species adapted to hunting underwater in Madagascar's fast-flowing mountain streams. Read the guide →

Fish EN White Cloud Mountain Minnow Tanichthys albonubes The white cloud mountain minnow was feared extinct in the wild for decades after its single known stream was developed, surviving mainly through aquarium populations. Read the guide →

Birds EN Whooping Crane Grus americana The whooping crane, the tallest bird in North America, was down to 15 individuals in 1941 and survives today only through decades of captive breeding and aircraft-led migration. Read the guide →

Invertebrates LC American Cockroach Periplaneta americana The American cockroach is one of the largest roaches to live alongside people, it is not American but African, it can run 50 body lengths a second, and it can survive about a week without its head. Read the guide →

Invertebrates LC Blue Land Crab Cardisoma guanhumi The blue land crab digs burrows far inland from the shore, only returning to the ocean to release its eggs, bridging land and sea for most of its adult life. Read the guide →

Fish LC Bluegill Lepomis macrochirus The bluegill is the small, deep-bodied sunfish behind more first fish caught in North America than any other species, and its breeding colonies feature a classic case of three different kinds of male. Read the guide →

Mammals NT Bush Dog Speothos venaticus The bush dog is a small, stocky South American canid that hunts cooperatively in packs and swims readily, pursuing prey through water as confidently as it does on land. Read the guide →

Amphibians LC Carpenter Frog Lithobates virgatipes The carpenter frog of the US Atlantic coast is named for a call like carpenters hammering nails, and it is one of the few frogs that breeds in the harsh acid water of a sphagnum bog. Read the guide →

Fish LC Channel Catfish Ictalurus punctatus The channel catfish is the most fished-for and most farmed catfish in the United States, a whiskered, scaleless fish that tastes the world with its entire skin and finds food in total darkness. Read the guide →

Fish LC Chinook Salmon Oncorhynchus tshawytscha The Chinook is the largest Pacific salmon, a fish that carries ocean nutrients far inland and feeds bears, eagles, and orcas, and whose river runs are among the most dammed in North America. Read the guide →

Amphibians EN Flatwoods Salamander Ambystoma cingulatum The flatwoods salamander lays its eggs in a dry pond basin and waits for autumn rain to flood it, a gamble that has made it one of the most endangered amphibians in the eastern United States. Read the guide →

Amphibians LC Marbled Newt Triturus marmoratus The marbled newt of France and Iberia is one of the largest and most striking European newts, bright green marbled with black, and where its range meets the great crested newt the two interbreed. Read the guide →

Birds LC Red-winged Blackbird Agelaius phoeniceus The red-winged blackbird, one of North America's most abundant birds, is a black marsh bird whose red shoulder patches are a badge it can flash to warn off rivals or hide to pass unseen. Read the guide →

Fish LC Striped Bass Morone saxatilis The striped bass is the great migratory sport fish of the US Atlantic coast, a silver, seven-striped river-spawning predator whose 1980s collapse and recovery is a fisheries classic. Read the guide →

Birds LC American Woodcock Scolopax minor The American woodcock is a shorebird that lives in the forest, with eyes set so far back it can see behind itself, a bill that probes soil for worms, and a rocking walk that made it an internet star. Read the guide →

Birds LC Bare-faced Ibis Phimosus infuscatus The bare-faced ibis probes damp South American grassland and wetland soil with a curved bill, its reddish facial skin visible from a distance against dark plumage. Read the guide →

Birds LC Black-headed Duck Heteronetta atricapilla The black-headed duck is the only duck species known to be an obligate brood parasite, laying every egg in the nests of other birds and never raising its own young. Read the guide →

Birds LC Brazilian Teal Amazonetta brasiliensis The Brazilian teal is one of South America's most common ducks, identified by a bright red bill and legs in males against otherwise brown plumage. Read the guide →

Fish LC Brown Trout Salmo trutta The brown trout is the trout of European rivers and the birthplace of fly fishing, one species ranging from small stream fish to sea-run giants, and a major invasive threat where it was introduced. Read the guide →

Birds LC Cinereous Harrier Circus cinereus The cinereous harrier hunts by flying low over Patagonian marshes and grassland, males pale grey and females a streaked brown, a difference typical of harriers worldwide. Read the guide →

Birds LC Cocoi Heron Ardea cocoi The cocoi heron is South America's largest heron, standing motionless at the water's edge before spearing fish with a rapid strike of its long bill. Read the guide →

Birds LC Comb Duck Sarkidiornis sylvicola The comb duck is named for the large fleshy knob breeding males grow atop the bill, one of the most distinctive ornaments of any South American waterfowl. Read the guide →

Fish LC Creole Perch Percichthys trucha The creole perch is a native Patagonian freshwater fish increasingly outcompeted in its own rivers and lakes by introduced trout and salmon. Read the guide →

Amphibians LC Four-toed Salamander Hemidactylium scutatum The four-toed salamander is a small lungless amphibian of mossy North American wetlands, named for a missing toe, with a break point at the base of its tail and a habit of nesting in shared clutches. Read the guide →

Birds LC Giant Coot Fulica gigantea The giant coot builds nest mounds of piled vegetation so large they can weigh over a tonne, anchored to the floor of high Andean lakes. Read the guide →

Fish LC Golden Dorado Salminus brasiliensis The golden dorado is a powerful South American river predator nicknamed the river tiger, prized by anglers for its spectacular aerial leaps when hooked. Read the guide →

Amphibians LC Green Frog Lithobates clamitans The green frog is the frog most people meet at the edge of a pond in eastern North America, the one that gives a single low twang like a loose banjo string and dives with a startled squawk. Read the guide →

Birds CR Hooded Grebe Podiceps gallardoi The hooded grebe performs an elaborate synchronized courtship dance on remote Patagonian plateau lakes, a ritual now threatened by introduced predators. Read the guide →

Birds LC Lake Duck Oxyura vittata The lake duck is a small South American diving duck best known for an extraordinary biological record, a male reproductive organ far longer than its entire body. Read the guide →

Birds CR Madagascar Fish Eagle Haliaeetus vociferoides The Madagascar fish eagle is one of the rarest raptors on Earth, with only a small number of breeding pairs left along the island's rivers, lakes, and coastline. Read the guide →

Birds CR Madagascar Pochard Aythya innotata The Madagascar pochard was believed extinct for over a decade until a tiny population was rediscovered on a remote volcanic lake in 2006, making it one of the rarest birds on Earth. Read the guide →

Birds LC Masked Duck Nomonyx dominicus The masked duck is a small, secretive stiff-tailed duck that stays hidden in dense marsh vegetation, making it one of the least frequently seen ducks in the Americas. Read the guide →

Fish LC Muskellunge Esox masquinongy The muskellunge is the largest member of the pike family and the top predator of the North American lakes it lives in, an ambush hunter so hard to catch that anglers call it the fish of 10,000 casts. Read the guide →

Fish LC Pejerrey Odontesthes bonariensis The pejerrey is a silvery South American fish so prized for sport fishing that it has been introduced to lakes on multiple continents far outside its native range. Read the guide →

Amphibians LC Pig Frog Lithobates grylio The pig frog is a large, almost fully aquatic frog of southeastern US marshes, named for its deep pig-like grunt, and it supplies most of the wild frog legs eaten in the United States. Read the guide →

Fish LC Redtail Catfish Phractocephalus hemioliopterus The redtail catfish grows over a metre long with a distinctive reddish-orange tail, an opportunistic Amazon basin predator popular with aquarium keepers despite its eventual size. Read the guide →

Birds LC Rosy-billed Pochard Netta peposaca The rosy-billed pochard is identified by a swollen, bright rosy-red knob at the base of the male's bill, a diving duck common across southern South American wetlands. Read the guide →

Fish LC Silver Dollar Fish Metynnis argenteus The silver dollar fish is a flat, round-bodied Amazon basin species named for its resemblance to a shining coin, a peaceful schooling relative of the piranha. Read the guide →

Birds LC Smooth-billed Ani Crotophaga ani The smooth-billed ani nests communally, with multiple females laying their eggs together in a single shared nest raised cooperatively by the whole group. Read the guide →

Birds LC Spot-flanked Gallinule Porphyriops melanops The spot-flanked gallinule is a small, secretive marsh bird of South America, identified by white-spotted flanks against otherwise dark plumage. Read the guide →

Fish LC Tambaqui Colossoma macropomum The tambaqui is one of the largest scaled freshwater fish in South America, using flat, molar-like teeth to crack open nuts and seeds that fall into flooded Amazon forest. Read the guide →

Fish LC Trahira Hoplias malabaricus The trahira is an aggressive ambush predator nicknamed the wolf fish, able to breathe air and survive in oxygen-poor South American rivers and swamps. Read the guide →

Fish LC Walleye Sander vitreus The walleye is a large member of the perch family with a mirror behind its eye that lets it hunt in near-darkness; it is the most prized freshwater food fish across much of the northern US and Canada. Read the guide →

Birds LC Whistling Heron Syrigma sibilatrix The whistling heron hunts insects across dry grassland far from water more often than most herons, named for its distinctive whistling call. Read the guide →

Birds LC White-faced Whistling Duck Dendrocygna viduata The white-faced whistling duck is one of the few duck species native to both South America and Africa, instantly recognizable by its bright white face against a dark body. Read the guide →

Birds LC Yellow-billed Pintail Anas georgica The yellow-billed pintail ranges from high Andean lakes to sub-Antarctic islands, identified by a bright yellow bill against mottled brown plumage. Read the guide →

Birds LC Chilean Swallow Tachycineta meyeni The Chilean swallow migrates seasonally across southern South America, nesting in tree cavities and abandoned woodpecker holes rather than building a nest from scratch. Read the guide →

Birds LC Dark-bellied Cinclodes Cinclodes patagonicus The dark-bellied cinclodes forages by walking along the water's edge rather than flying, a ground-based hunting style shared with other cinclodes species of Patagonian streams and shorelines. Read the guide →

Mammals LC Four-eyed Opossum Philander opossum The four-eyed opossum carries two pale spots above its eyes that resemble a second pair, a nocturnal and solitary marsupial found across a broad stretch of the Americas. Read the guide →

Amphibians CR Loa Water Frog Telmatobius dankoi The Loa water frog survives in a single isolated stretch of river within Chile's Atacama Desert, making it one of the rarest and most narrowly distributed amphibians on Earth. Read the guide →

Birds LC Magellanic Oystercatcher Haematopus leucopodus The Magellanic oystercatcher probes rocky and sandy shorelines for shellfish with a long, bright orange bill, its bold black-and-white plumage and pink legs standing out along Patagonian coasts. Read the guide →

Birds LC Plumbeous Rail Pardirallus sanguinolentus The plumbeous rail moves secretively through dense marsh vegetation, its dark slate-grey plumage and bright red legs and bill base rarely seen despite the species' wide South American range. Read the guide →

Fish LC Puye Galaxias maculatus The puye migrates between rivers and the sea across an extraordinary Southern Hemisphere range, found in South America, New Zealand, and Australia despite its small size and short lifespan. Read the guide →

Fish LC Rainbow Trout Oncorhynchus mykiss The rainbow trout is a cold-water fish of western North America, farmed and stocked into about a hundred countries; its sea-run form, the steelhead, is the same species after a life at sea. Read the guide →

Birds LC Southern Screamer Chauna torquata The southern screamer produces a trumpeting call audible for kilometres, a large, goose-like bird armed with sharp spurs on its wings for territorial combat. Read the guide →

Birds LC Spectacled Tyrant Hymenops perspicillatus The spectacled tyrant perches conspicuously near water, males marked by a bright yellow eye-ring and wing patch standing out sharply against otherwise black plumage. Read the guide →

Invertebrates LC Water Strider Gerridae The water strider walks on the surface of ponds and even the open ocean, held up by water-repellent hairs on its legs; it hunts by feeling the ripples of insects that fall onto the water. Read the guide →

Reptiles LC Yellow Anaconda Eunectes notaeus The yellow anaconda constricts prey rather than using venom, one of the largest snake species in South America, found gliding through wetlands across Paraguay, Bolivia, and northern Argentina. Read the guide →

Birds VU Andean Flamingo Phoenicoparrus andinus The Andean flamingo is the rarest flamingo species in the world, breeding on remote high-altitude salt flats where thin air and freezing nights make survival a genuine challenge. Read the guide →

Birds LC Andean Goose Chloephaga melanoptera The Andean goose lives at higher altitude than any of its Patagonian relatives, grazing the edges of high-Andean lakes and bogs thousands of metres above sea level. Read the guide →

Birds LC Austral Negrito Lessonia rufa The austral negrito shows one of the sharpest differences between the sexes of any Patagonian songbird, males jet black with a white wing patch, females a plain brown. Read the guide →

Birds LC Buff-necked Ibis Theristicus caudatus The buff-necked ibis forages across open grassland rather than wading through deep water like most ibis species, using its long curved bill to probe soil for worms and insects. Read the guide →

Amphibians VU California Red-legged Frog Rana draytonii The California red-legged frog is the largest native frog in the western US and the model for Mark Twain's jumping-frog story; introduced bullfrogs and lost wetlands have made it a threatened species. Read the guide →

Amphibians VU California Tiger Salamander Ambystoma californiense The California tiger salamander spends most of the year in rodent burrows, surfacing on rainy nights to breed in vernal pools; farmland, sprawl, and an invasive cousin have made it threatened. Read the guide →

Birds NT Chilean Flamingo Phoenicopterus chilensis The Chilean flamingo is the southernmost breeding flamingo species in the world, filtering tiny crustaceans and algae from soda lakes and coastal lagoons across southern South America. Read the guide →

Birds LC Chiloe Wigeon Mareca sibilatrix The Chiloe wigeon grazes on grass like a goose more than it dabbles like a typical duck, sporting a metallic green head patch unlike the rufous heads of most other wigeon species. Read the guide →

Fish VU Common Carp Cyprinus carpio Farmed for two thousand years and bred into koi, the common carp has been released across the world, where its habit of rooting up the bottom makes it one of the most damaging of all invasive fish. Read the guide →

Birds LC Coscoroba Swan Coscoroba coscoroba The coscoroba swan is the smallest and most goose-like of the swans, the sole member of its own genus, distinguished from true swans by its shorter neck and bright red bill. Read the guide →

Amphibians NT Crawfish Frog Lithobates areolatus The crawfish frog of the American Midwest lives year-round in an abandoned crayfish burrow, ambushing insects from the entrance, and it has one of the loudest calls of any North American frog. Read the guide →

Birds LC Crested Duck Lophonetta specularioides The crested duck sports a shaggy tuft of feathers on the back of its head, ranging from lowland Patagonian coastlines to high-altitude Andean lakes across a remarkably wide range of elevations. Read the guide →

Reptiles LC Eastern Copperhead Agkistrodon contortrix The eastern copperhead, a camouflaged pit viper of the US East and Midwest, causes more venomous bites than any other American snake and among the fewest deaths, because its venom is mild. Read the guide →

Amphibians LC Four-eyed Frog Pleurodema thaul The four-eyed frog startles predators by arching its back to reveal two large eye-like markings on its rump, a bluff aimed squarely away from its actual head. Read the guide →

Birds LC Great Grebe Podiceps major The great grebe is the largest grebe species in South America, an elegant diving waterbird capable of both freshwater lake and sheltered coastal marine habitat. Read the guide →

Birds NT James's Flamingo Phoenicoparrus jamesi James's flamingo was believed extinct for decades before a breeding colony was rediscovered on a remote high-Andean salt lake, and it remains the smallest of the world's flamingo species. Read the guide →

Birds LC Magellanic Snipe Gallinago magellanica The Magellanic snipe probes deep into soft mud with a long, flexible bill, its cryptic plumage making it nearly invisible until it bursts into flight at the last moment. Read the guide →

Amphibians EN Mountain Yellow-legged Frog Rana muscosa Once the most abundant amphibian in California's high Sierra, the mountain yellow-legged frog was driven to the brink by stocked trout and a fungal disease, then partly rescued by removing the fish. Read the guide →

Mammals NT Neotropical Otter Lontra longicaudis The neotropical otter has the broadest range of any otter species in the Americas, found from tropical Mexican rivers all the way south into the cooler waters of northern Patagonia. Read the guide →

Fish LC Northern Pike Esox lucius The northern pike is the ambush predator of cool fresh water across the northern hemisphere, a long green fish with a duck-bill snout, hundreds of teeth, and a lunge like a released spring. Read the guide →

Amphibians EN Patagonia Frog Atelognathus patagonicus The Patagonia frog spends almost its entire life in a handful of cold Andean lakes, its restricted range now threatened by introduced trout that prey heavily on its tadpoles. Read the guide →

Birds LC Puna Ibis Plegadis ridgwayi The puna ibis breeds on high-altitude Andean wetlands, its glossy dark plumage catching an iridescent sheen as it wades through shallow water probing for invertebrates. Read the guide →

Amphibians LC Smooth Newt Lissotriton vulgaris The smooth newt is the most common newt in Britain and much of Europe, a small amphibian that spends most of the year on land, breeds in ponds, and courts by fanning water at the female with its tail. Read the guide →

Birds LC Southern Lapwing Vanellus chilensis The southern lapwing is one of the most conspicuous and vocal birds of open South American habitat, using loud alarm calls and aggressive aerial dives to defend its nest against intruders. Read the guide →

Mammals EN Southern River Otter Lontra provocax The southern river otter is an Endangered species of southern Chile and Argentina, hunted heavily for its fur in the twentieth century and now surviving in fragmented river and coastal populations. Read the guide →

Birds LC Spectacled Duck Speculanas specularis The spectacled duck nests in tree cavities along forested Patagonian streams, unlike most ducks, males marked by a distinctive pale ring of feathers resembling a pair of spectacles. Read the guide →

Birds LC Torrent Duck Merganetta armata The torrent duck lives permanently on fast-flowing Andean mountain rivers, diving and swimming against powerful currents that would sweep away almost any other waterfowl species. Read the guide →

Birds LC White-tufted Grebe Rollandia rolland The white-tufted grebe displays a striking golden-white plume fanning out behind each eye during the breeding season, diving for small fish and invertebrates across South American lakes and lagoons. Read the guide →

Birds LC Yellow-billed Teal Anas flavirostris The yellow-billed teal ranges from high Andean lakes in Colombia all the way south to Tierra del Fuego, one of the broadest latitudinal ranges of any South American duck. Read the guide →

Birds LC Black-necked Swan Cygnus melancoryphus The black-necked swan is South America's only swan species, marked by a striking white body and jet-black neck and head that set it apart from the all-white swans of the Northern Hemisphere. Read the guide →

Reptiles VU Burmese Python Python bivittatus The Burmese python is one of the largest snakes in the world, a heavy-bodied constrictor from Southeast Asia that has become a devastating invasive predator in the Florida Everglades. Read the guide →

Birds LC Common Nightingale Luscinia megarhynchos The common nightingale is a plain brown bird with an extraordinary voice; males sing through the night as well as the day, drawing on a repertoire of around a thousand different sounds. Read the guide →

Birds LC Flying Steamer Duck Tachyeres patachonicus The flying steamer duck is the only steamer duck species capable of true flight, setting it apart from several closely related, heavier-bodied relatives that have lost the ability entirely. Read the guide →

Amphibians NT Gopher Frog Lithobates capito The gopher frog of the southeastern US spends most of its life sheltering in the burrow of a gopher tortoise, coming out on rainy winter nights to breed explosively in temporary, fishless ponds. Read the guide →

Fish LC Largemouth Bass Micropterus salmoides The largemouth bass is North America's most popular freshwater game fish, an ambush predator of weedy lakes and ponds that has been introduced to dozens of countries, where it often turns invasive. Read the guide →

Birds LC Magellanic Plover Pluvianellus socialis The Magellanic plover is so taxonomically distinct that it is the only member of its own family, a small Patagonian wading bird that feeds its chicks by direct regurgitation. Read the guide →

Amphibians LC Pickerel Frog Lithobates palustris The pickerel frog is the only frog native to North America with skin toxic enough to matter, strong enough to kill other frogs shut in a bag with it and to make most snakes leave it alone. Read the guide →

Birds LC Silvery Grebe Podiceps occipitalis The silvery grebe forms dense, sociable breeding colonies on lakes across southern South America, diving underwater to hunt small fish and invertebrates using feet set far back on its body. Read the guide →

Mammals VU Asian Small-Clawed Otter Aonyx cinereus The Asian small-clawed otter is the smallest otter species in the world, using unusually dexterous, only partly webbed paws to feel for shellfish and crabs rather than relying on sight. Read the guide →

Mammals VU Barasingha Rucervus duvaucelii The barasingha takes its name from antlers that can carry twelve or more points, an Indian swamp deer brought back from the edge of extinction through decades of protection. Read the guide →

Mammals LC Bushbuck Tragelaphus sylvaticus The bushbuck is the smallest of the spiral-horned antelope, a solitary, secretive forest dweller marked with white spots and stripes that freezes rather than flees when threatened. Read the guide →

Mammals LC Crab-Eating Mongoose Herpestes urva The crab-eating mongoose has partially webbed feet for swimming after its favourite prey, an Asian mongoose species that forages along streams and rice paddies rather than dry savanna. Read the guide →

Reptiles VU Eastern Box Turtle Terrapene carolina The eastern box turtle is a small land turtle of the eastern US that can fold its hinged shell shut into a sealed box, lives for many decades, and stays in a home range of a few hectares for life. Read the guide →

Mammals LC Egyptian Mongoose Herpestes ichneumon The Egyptian mongoose is the only mongoose species established wild in Europe, valued for centuries as a natural controller of snakes and rodents around human settlements. Read the guide →

Mammals LC Eurasian Otter Lutra lutra The Eurasian otter recovered dramatically after near-extinction from pollution across much of Europe, now serving as a living indicator of healthy river water quality wherever it returns. Read the guide →

Mammals CR European Mink Mustela lutreola The European mink has been pushed toward extinction largely by its own invasive American relative, escaped fur-farm animals that outcompete it wherever the two species overlap. Read the guide →

Reptiles LC Green Anole Anolis carolinensis The green anole is a small southeastern US lizard sold as an American chameleon for its green-to-brown colour change, though it is no chameleon and is being pushed up into the treetops by an invader. Read the guide →

Mammals EN Hairy-Nosed Otter Lutra sumatrana The hairy-nosed otter is one of the rarest and least-studied otter species in the world, identified by a fully furred nose unlike the bare noses of its close relatives. Read the guide →

Mammals LC Kob Kobus kob The kob relies on a unique mating system where males display and compete on tiny territories called leks, a reddish-brown floodplain antelope closely related to the waterbuck. Read the guide →

Mammals NT Lechwe Kobus leche The lechwe has water-repellent, oily fur and elongated hooves built for splashing through shallow floodplains at speed, often forming herds tens of thousands strong. Read the guide →

Mammals LC Long-Nosed Mongoose Xenogale naso The long-nosed mongoose has an unusually elongated snout and a partly aquatic lifestyle, a poorly studied Central African rainforest species that forages along streams and swampy ground. Read the guide →

Mammals LC Marsh Mongoose Atilax paludinosus The marsh mongoose forages almost entirely along riverbanks and wetlands, an excellent swimmer despite lacking webbed feet, using dexterous paws to crack open crabs and mussels. Read the guide →

Mammals EN Otter Civet Cynogale bennettii The otter civet has evolved webbed feet and dense, water-resistant fur strikingly similar to a true otter, despite belonging to an entirely different carnivore family. Read the guide →

Mammals EW Pere David's Deer Elaphurus davidianus Pere David's deer vanished from the wild in China over a century ago, surviving only in European deer parks before descendants were eventually returned to reestablish the species. Read the guide →

Mammals LC Southern Reedbuck Redunca arundinum The southern reedbuck relies on a piercing whistled alarm call and tall reedbeds for cover, a shy grassland antelope rarely seen far from water. Read the guide →

Mammals LC Ring-Tailed Vontsira Galidia elegans The ring-tailed vontsira is Madagascar's most commonly seen native carnivore, an active daytime hunter belonging to the same island-exclusive family as the fossa and fanaloka. Read the guide →

Mammals VU Sambar Deer Rusa unicolor The sambar deer is one of the largest deer species in Asia, a shaggy, water-loving giant that wallows in mud to cool off and serves as one of the tiger's most important prey species across its range. Read the guide →

Mammals LC Sitatunga Tragelaphus spekii The sitatunga has splayed, elongated hooves built for walking on floating swamp vegetation, and can submerge almost entirely underwater to hide from predators. Read the guide →

Mammals LC Stripe-Necked Mongoose Herpestes vitticollis The stripe-necked mongoose carries a bold dark stripe running down the side of its neck, one of the larger Asian mongoose species found across the forests of southern India and Sri Lanka. Read the guide →

Mammals VU Water Deer Hydropotes inermis The water deer is the only deer species that grows no antlers at all in either sex, relying instead on long, visible tusks that have earned it an occasional nickname as the vampire deer. Read the guide →

Mammals LC Waterbuck Kobus ellipsiprymnus The waterbuck secretes an oily, musky substance that may make its meat unpalatable to predators, a shaggy African antelope with a white target-like ring around its rump. Read the guide →

Birds LC Amazon Kingfisher Chloroceryle amazona The Amazon kingfisher is the largest of the green-backed American kingfishers, favouring the wider rivers that its smaller relative the green kingfisher tends to avoid. Read the guide →

Birds LC American Coot Fulica americana The American coot swims with lobed rather than webbed toes, an unusual adaptation among waterbirds, while chicks flash a shock of orange fuzz that parents seem to specifically favour when feeding. Read the guide →

Mammals LC American Water Shrew Sorex palustris The American water shrew can run briefly across the surface of water, trapped air bubbles under its fringed feet keeping it from sinking for a few crucial seconds. Read the guide →

Birds LC Azure Kingfisher Ceyx azureus The azure kingfisher flashes along quiet Australian forest streams like a living jewel, its deep blue back and orange underparts visible only in a brief blur before it vanishes back into the shadows. Read the guide →

Birds LC Baillon's Crake Zapornia pusilla Baillon's crake ranks among the smallest rails on Earth, a tiny reed-bed specialist found across an enormous range spanning Europe, Africa, Asia, and Australia yet rarely glimpsed anywhere within it. Read the guide →

Birds LC Black-crowned Night-Heron Nycticorax nycticorax The black-crowned night-heron is one of the most widespread herons in the world, a stocky, red-eyed hunter that does most of its feeding after dark while other herons sleep. Read the guide →

Birds LC Black-headed Gull Chroicocephalus ridibundus Despite its name, the black-headed gull's breeding hood is chocolate-brown rather than true black, and for much of the year it wears a plain white head with a small dark ear spot instead. Read the guide →

Birds LC Black Heron Egretta ardesiaca The black heron hunts by forming its wings into an umbrella-like canopy over the water, a highly unusual behaviour that creates shade to help it spot fish hiding beneath. Read the guide →

Birds NT Black Rail Laterallus jamaicensis The black rail is the smallest rail in North America, a sparrow-sized marsh bird so secretive that most of what is known about it comes from its distinctive nighttime calls. Read the guide →

Birds LC Black Tern Chlidonias niger The black tern breaks the usual seabird mould, breeding on freshwater marshes far from any coast and wearing an almost entirely black breeding plumage unlike beach-dwelling terns. Read the guide →

Birds LC Boat-billed Heron Cochlearius cochlearius The boat-billed heron carries an enormously broad, shovel-shaped bill unlike any other heron, a tool suited to a nocturnal life spent hunting through dark mangrove waters. Read the guide →

Birds LC Caspian Tern Hydroprogne caspia The Caspian tern is the largest tern in the world, armed with a massive, blood-red bill powerful enough to seize fish that would challenge much smaller tern species entirely. Read the guide →

Birds LC Clapper Rail Rallus crepitans The clapper rail thrives in salt marsh where few other rails can survive, its harsh clattering call carrying across the exposed, tidal grasslands it calls home along the Atlantic and Gulf coasts. Read the guide →

Birds LC Collared Kingfisher Todiramphus chloris The collared kingfisher holds one of the widest ranges of any kingfisher, thriving in mangroves, gardens, and coastal towns from the Red Sea to Australia and the Pacific. Read the guide →

Birds LC Common Gallinule Gallinula galeata The common gallinule looks nearly identical to the Old World common moorhen, a resemblance so close the two were treated as a single species until genetic evidence split them apart in 2011. Read the guide →

Birds LC Common Moorhen Gallinula chloropus The common moorhen walks confidently across floating vegetation on long, unwebbed toes, a species so similar to its American relative the two were only split apart in 2011. Read the guide →

Birds LC Common Tern Sterna hirundo The common tern hunts by hovering above the water before folding its wings into a sharp plunge dive, a hunting style that has earned terns the nickname "sea swallows" for their agile, buoyant flight. Read the guide →

Birds LC Corncrake Crex crex The corncrake lives in hay meadows rather than marshes, its rasping "crex-crex" call giving the species its scientific name, while mechanised mowing pushed it toward decline in Western Europe. Read the guide →

Birds LC Eurasian Coot Fulica atra The Eurasian coot carries a bright white frontal shield above its bill, a feature so recognisable it inspired the phrase "as bald as a coot" for its stark, feather-free forehead. Read the guide →

Mammals LC Eurasian Water Shrew Neomys fodiens The Eurasian water shrew is one of the very few venomous mammals alive, delivering a mild toxin through its bite that can subdue prey considerably larger than itself. Read the guide →

Birds LC Franklin's Gull Leucophaeus pipixcan Franklin's gull breeds far from any ocean on prairie wetlands across the North American interior, following farm ploughs for insects so readily that it earned the nickname prairie dove. Read the guide →

Birds LC Giant Kingfisher Megaceryle maxima The giant kingfisher is the largest kingfisher found anywhere in Africa, a powerful hunter capable of taking prey well beyond the small fish that make up most kingfishers' diets. Read the guide →

Birds LC Goliath Heron Ardea goliath The goliath heron is the largest living heron in the world, a towering hunter powerful enough to catch and swallow fish that would overwhelm almost any other wading bird. Read the guide →

Amphibians LC Gray Treefrog Hyla versicolor The gray treefrog of eastern North America can shift between grey, green, and brown to match bark or leaves, survives its body partly freezing solid each winter, and carries four sets of chromosomes. Read the guide →

Birds LC Great Egret Ardea alba The great egret was hunted to the brink in the late 1800s for its ornamental breeding plumes, a slaughter so severe it helped spark the modern bird conservation movement. Read the guide →

Birds LC Green Kingfisher Chloroceryle americana The green kingfisher favours narrow, sheltered streams that its much larger relative the ringed kingfisher tends to avoid, letting the two related hunters share the same rivers. Read the guide →

Birds LC Grey Heron Ardea cinerea The grey heron is the Old World counterpart to the great blue heron, a tall, patient hunter that stands motionless at the water's edge before striking with lightning speed. Read the guide →

Birds LC Gull-billed Tern Gelochelidon nilotica The gull-billed tern carries a thick, black, gull-like bill instead of the slender pointed bill typical of most terns, and hunts as often over dry land as over water. Read the guide →

Birds NT King Rail Rallus elegans The king rail is the largest rail species in North America, a freshwater marsh specialist whose numbers have quietly declined for decades as the wetlands it depends on continue to disappear. Read the guide →

Birds LC Little Blue Heron Egretta caerulea The little blue heron hatches entirely white and only gradually turns its adult slate-blue colour, passing through an unusual patchy blue-and-white phase along the way. Read the guide →

Birds LC Little Crake Zapornia parva The little crake is one of the smallest members of the entire rail family, a diminutive marsh bird that slips through reed beds so quietly its presence often goes entirely unnoticed. Read the guide →

Birds LC Little Egret Egretta garzetta The little egret is the Old World counterpart to the snowy egret, sharing the same black legs and bright yellow feet used to stir up hidden prey in shallow water. Read the guide →

Birds LC Malachite Kingfisher Corythornis cristatus The malachite kingfisher is one of Africa's most photographed birds, a tiny jewel-toned hunter with a vivid turquoise back and orange underparts that perches low over still water. Read the guide →

Birds LC Oriental Dwarf Kingfisher Ceyx erithacus The oriental dwarf kingfisher ranks among the smallest kingfishers in the world, a tiny burst of orange, purple, and blue that vanishes into the forest understory almost as soon as it is seen. Read the guide →

Birds LC Pied Kingfisher Ceryle rudis The pied kingfisher hunts by hovering in mid-air over open water before folding its wings and dropping straight down onto a fish, a technique most other kingfishers never use at all. Read the guide →

Birds LC Purple Gallinule Porphyrio martinica The purple gallinule wears an almost impossibly vivid combination of purple, blue, and green, walking across lily pads on long yellow toes that spread its weight evenly enough to avoid sinking. Read the guide →

Birds LC Purple Heron Ardea purpurea The purple heron is a slimmer, more secretive relative of the grey heron, favouring dense reed beds over open water and blending its chestnut and slate plumage into marsh vegetation. Read the guide →

Birds LC Purple Swamphen Porphyrio porphyrio The purple swamphen wields a massive red bill capable of tearing apart tough reed stems, using an oversized foot to hold food steady while it feeds like a bird with hands. Read the guide →

Mammals EN Pygmy Hippo Choeropsis liberiensis The pygmy hippo is a shy, nocturnal forest animal of West Africa that weighs about a tenth as much as the common hippo, lives mostly on land near water, and is now endangered. Read the guide →

Birds LC Ringed Kingfisher Megaceryle torquata The ringed kingfisher is the largest kingfisher found anywhere in the Americas, a chunky, loud-calling hunter whose rattling cry often announces its presence along a riverbank before it is ever seen. Read the guide →

Birds VU Sarus Crane Antigone antigone The sarus crane is the tallest flying bird in the world, standing up to 1.8 metres, and in India it is a lasting symbol of marital devotion because pairs bond and hold a territory for life. Read the guide →

Birds LC Snowy Egret Egretta thula The snowy egret hunts by shuffling its bright yellow feet through shallow water to flush hidden prey before striking, a trick that earned those feet the nickname golden slippers. Read the guide →

Birds LC Sora Porzana carolina The sora is the most abundant rail in North America, betraying its presence in dense marsh vegetation with a distinctive descending whinny few visitors ever manage to trace back to the bird itself. Read the guide →

Birds LC Spotted Crake Porzana porzana The spotted crake wears a body dusted with fine white spots and streaks, camouflage that helps it vanish almost completely into the dense marsh vegetation it rarely leaves. Read the guide →

Birds LC Stork-billed Kingfisher Pelargopsis capensis The stork-billed kingfisher carries a massive, thick red bill more reminiscent of a stork, a powerful tool that lets it take prey far beyond the small fish most kingfishers rely on. Read the guide →

Birds LC Tricolored Heron Egretta tricolor The tricolored heron chases its prey rather than waiting for it, darting through shallow water in a burst of energy unlike the patient hunting style typical of most other herons. Read the guide →

Birds LC Virginia Rail Rallus limicola The Virginia rail has a body flattened from side to side, an adaptation that lets it slip between dense marsh reeds without disturbing a single stalk, living up to the phrase "thin as a rail." Read the guide →

Birds LC Water Rail Rallus aquaticus The water rail produces a call so pig-like that its unearthly squeals from deep within a reed bed have convinced many a passerby that something else entirely was hiding in the marsh. Read the guide →

Birds LC Whiskered Tern Chlidonias hybrida The whiskered tern is a freshwater marsh specialist like its close relative the black tern, but keeps a sharp white cheek stripe against dark grey underparts rather than turning almost entirely black. Read the guide →

Birds VU Yellow Rail Coturnicops noveboracensis The yellow rail is one of the most elusive birds in North America, a tiny marsh dweller so reluctant to fly or be seen that many birders spend years searching before ever glimpsing one. Read the guide →

Birds CR Zapata Rail Cyanolimnas cerverai The Zapata rail survives only within Cuba's Zapata Swamp, a nearly flightless bird so rarely encountered that decades sometimes pass between confirmed sightings by researchers. Read the guide →

Fish LC Blue Acara Andinoacara pulcher The blue acara is speckled with iridescent turquoise flecks across a stout, hardy body, one of the more peaceful medium-sized cichlids widely recommended as an introduction to the family. Read the guide →

Birds LC Blue-And-Gold Macaw Ara ararauna The blue-and-gold macaw pairs a sky-blue back with a golden-yellow chest, one of the most recognisable large parrots of South American rainforest and a familiar sight at riverside clay licks. Read the guide →

Fish LC Bumblebee Cichlid Pseudotropheus crabro The bumblebee cichlid wears the yellow-and-black bands of its insect namesake, a pattern that closely resembles a bottom-dwelling catfish and may help it sneak close to mouthbrooding females. Read the guide →

Fish LC Celestial Pearl Danio Danio margaritatus The celestial pearl danio was unknown to science until 2006, and within months of its discovery a tiny, star-speckled fish barely two centimetres long had become a global aquarium sensation. Read the guide →

Fish LC Chili Rasbora Boraras brigittae The chili rasbora is barely two centimetres long yet burns with an intense red colour, one of the smallest schooling fish kept in aquariums and a favourite for tiny nano tanks. Read the guide →

Fish VU Chocolate Gourami Sphaerichthys osphromenoides The chocolate gourami is a shy, small-bodied labyrinth fish of Southeast Asian blackwater swamps that carries its eggs and young inside its mouth rather than building a bubble nest. Read the guide →

Reptiles LC Common Basilisk Basiliscus basiliscus The common basilisk of Central America is the original Jesus Christ lizard, able to sprint upright across the surface of a stream on its hind legs for a few metres before it sinks and swims off. Read the guide →

Fish LC Convict Cichlid Amatitlania nigrofasciata The convict cichlid wears bold, vertical black-and-white stripes like a cartoon prisoner, backed by a breeding drive so prolific that a single pair can quickly overwhelm an aquarium with fry. Read the guide →

Fish LC Demasoni Cichlid Pseudotropheus demasoni The demasoni cichlid is barely six centimetres long yet considered one of the most aggressive fish, inch for inch, in the entire mbuna group, requiring large groups just to spread out the hostility. Read the guide →

Fish LC Electric Yellow Cichlid Labidochromis caeruleus The electric yellow cichlid glows a solid, almost fluorescent yellow across its entire body, one of the most recognisable of the rock-dwelling mbuna cichlids endemic to Africa's Lake Malawi. Read the guide →

Fish LC Firemouth Cichlid Thorichthys meeki The firemouth cichlid flares an ember-coloured throat at rivals during territorial disputes, a bluffing display that usually settles conflicts before a single bite is thrown. Read the guide →

Fish LC Giant Danio Devario aequipinnatus The giant danio is the largest commonly kept member of the danio group, a fast, torpedo-shaped schooling fish that appreciates far more open swimming space than its smaller relatives. Read the guide →

Fish LC Glowlight Danio Danio choprae The glowlight danio carries a coppery-orange stripe that seems to glow along a slim, blue-black body, a relatively recent addition to the aquarium hobby compared with its longer-established relatives. Read the guide →

Fish LC Green Terror Andinoacara rivulatus The green terror carries a fearsome name earned by a territorial streak, with mature males developing a pronounced forehead hump and an iridescent green-and-orange sheen across the body. Read the guide →

Fish LC Honey Gourami Trichogaster chuna The honey gourami is one of the smallest and most peaceful gouramis kept in aquariums, with breeding males turning a warm honey-orange colour rarely seen outside the courtship season. Read the guide →

Birds VU Hyacinth Macaw Anodorhynchus hyacinthinus The hyacinth macaw is the longest parrot species in the world, wielding a bite powerful enough to crack the hardest palm nuts that most other animals in its habitat cannot even dent. Read the guide →

Fish LC Jack Dempsey Rocio octofasciata The Jack Dempsey cichlid was named after a heavyweight boxing champion for its pugnacious temperament, transforming from a drab grey juvenile into an adult spangled with iridescent blue-green flecks. Read the guide →

Fish LC Jewel Cichlid Hemichromis bimaculatus The jewel cichlid flushes a brilliant red studded with iridescent blue spangles when breeding, a burst of colour matched by some of the most aggressive parental defence in the aquarium hobby. Read the guide →

Fish LC Kribensis Pelvicachromis pulcher The kribensis is a small, peaceful West African cichlid in which the female often outshines the male, flushing a vivid purple-red belly that is brightest exactly when she is ready to breed. Read the guide →

Fish LC Kuhli Loach Pangio kuhlii The kuhli loach is a slender, eel-like bottom-dweller that squirms through gravel and leaf litter by day and only really becomes active once the aquarium lights go out. Read the guide →

Fish VU Licorice Gourami Parosphromenus deissneri The licorice gourami is a tiny, intensely coloured labyrinth fish restricted to disappearing peat-swamp pools, among the most threatened and least widely kept fish in the aquarium hobby. Read the guide →

Fish LC Panda Corydoras Corydoras panda The panda corydoras carries bold black eye and tail patches recalling its mammalian namesake, a small catfish that prefers noticeably cooler water than most of its relatives. Read the guide →

Amphibians LC Paradox Frog Pseudis paradoxa The paradox frog of South America is famous for a strange life history — its tadpole grows to around 25 cm, three or four times the length of the small adult frog it eventually becomes. Read the guide →

Fish LC Peacock Cichlid Aulonocara nyassae The peacock cichlid uses enlarged, sensory-lined cheek pores to detect prey hiding beneath sand, hunting by feel across Lake Malawi's open sandy floor rather than by sight alone. Read the guide →

Fish LC Pearl Danio Danio albolineatus The pearl danio carries an iridescent pinkish-purple sheen across its body that shifts and shimmers like the surface of a pearl as the fish moves through the water. Read the guide →

Fish LC Pearl Gourami Trichopodus leerii The pearl gourami is covered in fine, pale speckling that catches the light like scattered pearls, one of the more peaceful and widely kept species in the entire gourami family. Read the guide →

Fish LC Ram Cichlid Mikrogeophagus ramirezi The ram cichlid packs iridescent blue, yellow, and red into a body barely five centimetres long, a popular dwarf cichlid that is noticeably more sensitive to water quality than most. Read the guide →

Fish LC Red Zebra Cichlid Maylandia estherae The red zebra cichlid is often more orange than red, since its natural colouring varies enormously between individuals, sexes, and different rocky stretches of Lake Malawi. Read the guide →

Fish LC Scissortail Rasbora Rasbora trilineata The scissortail rasbora flicks its bold, black-and-white banded tail fin open and shut like a pair of scissors, a distinctive habit that gives the species both its name and its constant motion. Read the guide →

Fish LC Severum Heros severus The severum carries a deep, disc-shaped body reminiscent of a large discus, with young fish showing bold vertical banding that fades into a calmer, more mottled pattern with age. Read the guide →

Fish LC Sterbai Corydoras Corydoras sterbai The sterbai corydoras tolerates noticeably warmer water than most of its relatives, making it one of the few corydoras species that can comfortably share a tank with heat-loving fish like discus. Read the guide →

Fish LC Texas Cichlid Herichthys cyanoguttatus The Texas cichlid is the only cichlid species native to the United States, tolerating water temperatures far colder than almost any other member of a family famous for needing warmth. Read the guide →

Fish LC Three-Spot Gourami Trichopodus trichopterus The three-spot gourami is one of the most widely kept aquarium fish in the world, its two body spots and eye together forming the "three spots" that give the species its name. Read the guide →

Birds EN Yellow-Headed Amazon Amazona oratrix The yellow-headed amazon is renowned as one of the most talented talking parrots in the world, a reputation for mimicry that has driven relentless trapping and pushed the species toward extinction. Read the guide →

Fish LC Yoyo Loach Botia almorhae The yoyo loach carries a bold, zigzagging body pattern that some keepers read as a string of "Y" and "O" letters, spelling out the toy that gave the species its playful common name. Read the guide →

Fish LC Zebra Mbuna Maylandia zebra The zebra mbuna was one of the first Lake Malawi rock cichlids described, and its natural colour morphs vary so widely that different rocky outcrops can look like different species. Read the guide →

Mammals EN Amazon River Dolphin Inia geoffrensis The Amazon river dolphin can turn pink as it matures, the largest river dolphin in the world, navigating flooded forest and murky river water almost entirely by sound rather than sight. Read the guide →

Mammals VU Amazonian Manatee Trichechus inunguis The Amazonian manatee is the only manatee species living entirely in fresh water, spending its whole life within the Amazon River basin rather than ever entering the ocean its coastal relatives need. Read the guide →

Mammals LC American Mink Neovison vison The American mink hunts both on land and underwater along streams and marshes, a fierce predator whose introduction to Europe made it one of the more disruptive invasive carnivores there. Read the guide →

Mammals CR Baiji Lipotes vexillifer The baiji was declared functionally extinct after a 2006 survey found no individuals, a once-thriving Yangtze dolphin whose disappearance is one of the starkest modern conservation losses. Read the guide →

Mammals VU Bald Uakari Cacajao calvus The bald uakari's bright red bald face signals good health to potential mates, since illness and parasites cause the skin to fade to a duller shade. Read the guide →

Amphibians EN Bornean Flat-headed Frog Barbourula kalimantanensis The Bornean flat-headed frog is the only frog known to have no lungs at all. It breathes entirely through its skin, and its flattened body lets it stay pinned to the bed of cold, fast forest streams. Read the guide →

Mammals LC Coypu Myocastor coypus The coypu has bright orange front teeth stained by iron in the enamel, a semi-aquatic rodent whose fur-trade releases turned it into an invasive species worldwide. Read the guide →

Invertebrates NE Darwin's Bark Spider Caerostris darwini Darwin's bark spider builds the largest web of any spider — an orb up to 2.8 square metres slung across a river on anchor lines 25 metres long, from the toughest biological material known. Read the guide →

Mammals LC De Brazza's Monkey Cercopithecus neglectus The De Brazza's monkey can freeze motionless for hours to avoid detection, making this widespread swamp forest primate one of the hardest to actually spot. Read the guide →

Reptiles LC Eastern Mud Turtle Kinosternon subrubrum The eastern mud turtle spends much of the year buried in mud or leaf litter rather than open water, a small, secretive species equally comfortable walking overland as swimming its shallow wetlands. Read the guide →

Mammals LC Eurasian Harvest Mouse Micromys minutus The Eurasian harvest mouse weaves a spherical nest suspended among grass stems, using a prehensile tail to climb as one of the smallest rodents in the world. Read the guide →

Mammals LC Evening Bat Nycticeius humeralis The evening bat emerges earlier than many other bat species, often while there is still light in the sky, a small hunter raising young in tree cavities and Spanish moss across the Southeast. Read the guide →

Amphibians LC Fanged Frog Limnonectes larvaepartus The male fanged frog has a pair of bony tusks on its lower jaw for fighting rivals. This Sulawesi species is the only frog known to give birth to live tadpoles rather than laying eggs. Read the guide →

Mammals EN Ganges River Dolphin Platanista gangetica The Ganges river dolphin is functionally blind, having lost the ability to form images, relying on extraordinarily refined echolocation to hunt within the murky, sediment-heavy rivers of South Asia. Read the guide →

Mammals VU Gray-Headed Flying Fox Pteropus poliocephalus The gray-headed flying fox is Australia's largest bat, a keystone forest pollinator whose colonies can suffer mass die-offs when temperatures spike past 42 degrees Celsius. Read the guide →

Mammals LC Greater Bulldog Bat Noctilio leporinus The greater bulldog bat rakes its oversized clawed feet through the water to gaff fish detected by the ripples they leave, a hunting method unique among bats. Read the guide →

Mammals LC Greater Cane Rat Thryonomys swinderianus The greater cane rat is farmed widely across West Africa for its meat, a large semi-aquatic rodent capable of causing serious damage to sugarcane fields. Read the guide →

Mammals LC Hammer-Headed Bat Hypsignathus monstrosus Male hammer-headed bats gather at nightly display grounds and inflate an oversized larynx to honk for mates, giving Africa's largest bat one of the odder faces in nature. Read the guide →

Mammals LC Indian Flying Fox Pteropus giganteus The Indian flying fox roosts by day in colonies of thousands hanging from treetops, one of the largest bats in the world and a vital pollinator across South Asia's forests. Read the guide →

Mammals EN Indus River Dolphin Platanista minor The Indus river dolphin survives in only a fraction of its range, isolated into fragmented river stretches by irrigation barrages, a functionally blind species among the rarest freshwater cetaceans. Read the guide →

Mammals EN Irrawaddy Dolphin Orcaella brevirostris The Irrawaddy dolphin has a rounded, beakless head giving it an almost whale-like look, a species of coastal and river waters in Southeast Asia known for cooperating with fishers to herd fish. Read the guide →

Mammals EN Little Brown Bat Myotis lucifugus The little brown bat can catch hundreds of insects in a single hour using echolocation alone, a once-abundant species now devastated across much of its range by white-nose syndrome. Read the guide →

Mammals LC Lowland Paca Cuniculus paca The lowland paca uses hollow chambers in its skull to amplify alarm calls into a booming, resonant sound far louder than its stocky, spotted body would suggest. Read the guide →

Mammals LC Meadow Vole Microtus pennsylvanicus The meadow vole reproduces so quickly a single pair could theoretically produce over a million descendants a year, a foundational prey species whose boom-and-bust cycles ripple through the food web. Read the guide →

Mammals LC Muskrat Ondatra zibethicus The muskrat builds dome-shaped lodges out of cattails and mud rising straight out of the marsh, engineering wetland habitat that dozens of other species end up relying on as well. Read the guide →

Mammals LC North American River Otter Lontra canadensis The North American river otter turns snow-covered riverbanks into a playground, tobogganing on its belly down slick slopes purely, it seems, for the fun of it, between serious bouts of fishing. Read the guide →

Reptiles VU Pig-nosed Turtle Carettochelys insculpta The pig-nosed turtle is the only freshwater turtle with true flippers like a sea turtle, and it has a fleshy pig-like snout it uses as a snorkel. Its eggs hatch only when a flood arrives. Read the guide →

Mammals LC Proboscis Bat Rhynchonycteris naso The proboscis bat roosts in neat head-to-tail lines along branches over water, its long pointed nose and mottled fur helping it blend seamlessly into tree bark. Read the guide →

Mammals LC Raccoon Dog Nyctereutes procyonoides The raccoon dog is a true canid that looks strikingly like a raccoon, one of the only dog family members capable of true hibernation, spending the coldest winter months in a den rather than active. Read the guide →

Reptiles LC Smooth Softshell Turtle Apalone mutica The smooth softshell turtle has a leathery, pancake-flat shell free of the bumps and spines found on its close relatives, an adaptation for burying itself almost completely in river sand. Read the guide →

Mammals LC Swamp Wallaby Wallabia bicolor The swamp wallaby is the only species in its genus and can carry an embryo in reserve even while still nursing an older joey, thanks to overlapping pregnancies. Read the guide →

Mammals NT Tucuxi Sotalia fluviatilis The tucuxi is often mistaken for a small bottlenose dolphin, sharing rivers with the larger Amazon river dolphin, a distinct species occupying freshwater rivers and coastal waters of South America. Read the guide →

Mammals LC Water Opossum Chironectes minimus The water opossum is the only truly aquatic marsupial, swimming with webbed hind feet, and even males carry a sealable pouch that protects them while diving. Read the guide →

Mammals VU Water Vole Arvicola amphibius The water vole, the real-life inspiration for Ratty in The Wind in the Willows, has vanished from most of Britain since American mink escaped into the wild. Read the guide →

Mammals LC White-Winged Vampire Bat Diaemus youngi The white-winged vampire bat feeds mainly on bird blood rather than mammal blood, setting it apart from its better-known relative, the common vampire bat. Read the guide →

Mammals CR Yangtze Finless Porpoise Neophocaena asiaeorientalis The Yangtze finless porpoise is the only surviving cetacean in the Yangtze River since the baiji disappeared, a small, smiling-faced species now the sole focus of urgent conservation efforts. Read the guide →

Fish LC Alabama Bass Micropterus henshalli The Alabama bass was only recognised as its own species after genetic study split it from the spotted bass, and its wide stocking has since caused hybridisation problems for other black bass. Read the guide →

Fish LC Arctic Grayling Thymallus arcticus The Arctic grayling carries an enormous, sail-like dorsal fin far larger than almost any other freshwater fish its size, displayed by males during courtship in the cold, clear rivers of the far north. Read the guide →

Invertebrates LC Baltimore Checkerspot Euphydryas phaeton The Baltimore checkerspot depends heavily on turtlehead, a wetland plant, for its caterpillars to survive their first winter huddled together in a communal silk web spun onto the host plant. Read the guide →

Fish LC Banded Pygmy Sunfish Elassoma zonatum The banded pygmy sunfish rarely grows longer than an inch and a half, a tiny predator of vegetation-choked swamps and ditches that spends its entire life hidden among dense aquatic plants. Read the guide →

Fish LC Bighead Carp Hypophthalmichthys nobilis The bighead carp filters plankton from the water using an enormous mouth, growing large enough and spreading fast enough since its introduction to threaten the food supply of native fish. Read the guide →

Reptiles LC Black-Knobbed Map Turtle Graptemys nigrinoda The black-knobbed map turtle carries a row of raised, dark-tipped knobs along its shell's central ridge, an unusually pronounced feature that makes it one of the more recognisable map turtles. Read the guide →

Birds LC Black Phoebe Sayornis nigricans The black phoebe rarely strays more than a few feet from water, perching low over streams and ponds to sally out after flying insects before returning to the exact same favoured perch again and again. Read the guide →

Fish NT Blueback Herring Alosa aestivalis The blueback herring migrates from the ocean into freshwater rivers in enormous numbers each spring to spawn, a journey that once supported major fisheries and still feeds many predators. Read the guide →

Fish LC Brook Silverside Labidesthes sicculus The brook silverside is capable of skittering across the water's surface in a series of rapid skips when startled, a behaviour distinctive enough to give the species one of its alternate common names. Read the guide →

Amphibians LC Brownback Salamander Eurycea aquatica The brownback salamander was only recognised as its own species after genetic study separated it from the wider dwarf salamander complex, a distinction invisible from appearance alone. Read the guide →

Fish VU Carolina Pygmy Sunfish Elassoma boehlkei The Carolina pygmy sunfish is known from only a small number of blackwater streams along the Carolina coastal plain, a tiny, rarely seen fish confined to a narrow strip of vegetated wetland habitat. Read the guide →

Fish LC Central Stoneroller Campostoma anomalum The central stoneroller grazes algae off rocks using a hard ridge on its lower jaw, and a breeding male develops a crown of large, sharp head tubercles used to battle rivals for spawning territory. Read the guide →

Birds LC Cinnamon Teal Spatula cyanoptera The cinnamon teal male displays some of the deepest, most saturated red-brown plumage of any North American duck, a colour so intense that it can appear almost glowing in strong sunlight. Read the guide →

Fish LC Cutlip Minnow Exoglossum maxillingua The cutlip minnow has a strange, three-lobed jaw used not for grazing algae but for nipping fins and scales off other fish, a specialised feeding habit unusual among small North American minnows. Read the guide →

Fish LC Cutthroat Trout Oncorhynchus clarkii The cutthroat trout takes its name from a bold slash of red or orange under its jaw, a feature distinctive enough to separate the species from other North American trout at a glance. Read the guide →

Amphibians LC Eastern Narrowmouth Toad Gastrophryne carolinensis The eastern narrowmouth toad specialises almost entirely on ants and termites, using a small, pointed head to push into tight nest galleries that would keep most other amphibians out entirely. Read the guide →

Fish LC Everglades Pygmy Sunfish Elassoma evergladei The Everglades pygmy sunfish thrives in some of the most crowded, vegetation-packed wetland water in Florida, a tiny predator so small that a single adult could rest comfortably across a fingertip. Read the guide →

Fish LC Flathead Chub Platygobio gracilis The flathead chub thrives in murky, sediment-heavy prairie rivers that many other fish avoid entirely, its flattened head and streamlined body suited to holding position against strong current. Read the guide →

Reptiles LC Florida Red-Bellied Cooter Pseudemys nelsoni The Florida red-bellied cooter often basks stacked several deep on a single log, its reddish underside and domed shell making it one of the most recognisable turtles in Florida's lakes and rivers. Read the guide →

Fish LC Glass Catfish Kryptopterus vitreus The glass catfish is a small Southeast Asian fish so transparent you can see its spine and internal organs through its skin. Schools of them can flash iridescent colours as they hover in the current. Read the guide →

Invertebrates LC Globe Skimmer Pantala flavescens The globe skimmer is the most widespread dragonfly on Earth and the longest-distance insect migrant, crossing the Indian Ocean on the monsoon winds in a relay of generations. Read the guide →

Fish NT Green Sturgeon Acipenser medirostris The green sturgeon spends most of its adult life in the open ocean, returning only to a few specific rivers to spawn, making it one of the most marine-oriented North American sturgeon species. Read the guide →

Reptiles EN Mary River Turtle Elusor macrurus The Mary River turtle lives in one Australian river, grows a mohawk of green algae, and can stay underwater for days by breathing through its cloaca. It was a common pet before science even named it. Read the guide →

Amphibians LC New Jersey Chorus Frog Pseudacris kalmi The New Jersey chorus frog was only recognised as its own species after study split it from the upland and southern chorus frogs, occupying a narrow strip of coastal plain habitat between them. Read the guide →

Birds LC Northern Harrier Circus hudsonius The northern harrier hunts by sound almost as much as sight, using an owl-like facial disc to funnel the rustle of hidden prey toward its ears while gliding low and slow over open grassland and marsh. Read the guide →

Fish LC Northern Madtom Noturus stigmosus The northern madtom hides beneath flat rocks and debris by day, emerging at night to hunt, using venomous spines as its main defence against predators that might otherwise make an easy meal of it. Read the guide →

Fish LC Northern Pikeminnow Ptychocheilus oregonensis The northern pikeminnow is the largest minnow native to North America, a predator significant enough that fisheries agencies pay anglers a bounty for every one caught to protect young salmon. Read the guide →

Amphibians VU Pedernales Mountain Salamander Eurycea pterophila The Pedernales mountain salamander survives only around a handful of spring-fed streams in central Texas, a fully aquatic species whose entire global range could be crossed on foot in an afternoon. Read the guide →

Fish LC Plains Killifish Fundulus zebrinus The plains killifish buries itself in loose, sandy streambeds to escape predators and extreme temperatures, a survival strategy suited to the wide, shallow, ever-shifting prairie rivers it calls home. Read the guide →

Fish LC Prickly Sculpin Cottus asper The prickly sculpin is covered in small, rough prickles across much of its skin, a texture unusual among freshwater fish that gives the species its name and sets it apart from smoother relatives. Read the guide →

Fish EN Pygmy Madtom Noturus stanauli The pygmy madtom is one of the smallest catfish in North America, a tiny, venomous-spined fish restricted to a couple of Tennessee River tributaries and considered one of the continent's rarest fish. Read the guide →

Fish LC Redeye Bass Micropterus coosae The redeye bass is restricted to clear, rocky upland streams in the southern Appalachians, a smaller, more stream-adapted relative of the largemouth and smallmouth bass with a strikingly red iris. Read the guide →

Fish NT Redside Dace Clinostomus elongatus The redside dace leaps clear out of the water to snatch flying insects just above the surface, a hunting technique unusual among small minnows and made possible by its unusually large, upturned mouth. Read the guide →

Fish VU Sacramento Perch Archoplites interruptus The Sacramento perch is the only sunfish native west of the Rocky Mountains, once the top native predator of California's Central Valley before introduced fish pushed it to the edge of its own range. Read the guide →

Birds LC Short-Eared Owl Asio flammeus The short-eared owl hunts readily in broad daylight, flying low over open fields with a floppy, moth-like wingbeat setting it apart from most other, strictly nocturnal North American owls. Read the guide →

Amphibians LC Sierran Treefrog Pseudacris sierra The Sierran treefrog was only recognised as its own species after genetic study split a once wide-ranging Pacific treefrog, dividing California's population from relatives to the north and south. Read the guide →

Amphibians LC Smallmouth Salamander Ambystoma texanum The smallmouth salamander forms all-female hybrid populations with close relatives, cloning itself generation after generation, almost as unusual as parthenogenetic whiptail lizards. Read the guide →

Reptiles LC Striped Swamp Snake Liodytes pygaea The striped swamp snake spends nearly all its life within dense aquatic vegetation, a small, secretive predator of southeastern wetlands rarely seen away from the plant mats it depends on for cover. Read the guide →

Reptiles LC Texas Cooter Pseudemys texana The Texas cooter is restricted almost entirely to river systems within the state its name references, a basking turtle whose narrow range makes it one of the more geographically specific US reptiles. Read the guide →

Fish LC Threespine Stickleback Gasterosteus aculeatus The threespine stickleback is a key example of evolution in action, with separate freshwater populations repeatedly evolving the same reduced armour and spines after colonising lakes from the sea. Read the guide →

Birds LC Tree Swallow Tachycineta bicolor The tree swallow switches to eating berries when cold snaps wipe out flying insects, a flexibility that lets it migrate farther north than most other aerial insect-hunting birds dare to. Read the guide →

Reptiles LC Western Fox Snake Pantherophis vulpinus The western fox snake vibrates its tail against dry vegetation to produce a buzz convincing enough that many people mistake this harmless constrictor for a rattlesnake and kill it out of fear. Read the guide →

Amphibians VU Helmeted Water Toad Calyptocephalella gayi The helmeted water toad of central Chile is one of the world's largest frogs and eats fish, birds, and other frogs. It is also the last of a frog family over 100 million years old. Read the guide →

Reptiles LC Elephant Trunk Snake Acrochordus javanicus The elephant trunk snake is a wholly aquatic Southeast Asian snake with baggy, warty skin several sizes too big for it. It grips slippery fish with its file-like scales and is nearly helpless on land. Read the guide →

Invertebrates NE Mosquito Anopheles gambiae The mosquito kills more people than any other animal on Earth, spreading malaria, dengue, and other diseases to hundreds of millions a year. Only the females bite, for the protein to make eggs. Read the guide →

Birds LC Ruff Calidris pugnax The ruff is a wading bird with three fixed kinds of male, set by one block of genes. Most fight over a lek, some hang around as pale satellites, and a rare few disguise themselves as females. Read the guide →

Fish LC Climbing Perch Anabas testudineus The climbing perch breathes air, survives days on land, and lurches overland on its gill covers to reach new pools. In Australia it is feared as an invader that chokes the predators that eat it. Read the guide →

Amphibians LC Crucifix Frog Notaden bennettii The crucifix frog is a round Australian frog marked with a cross of coloured spots. Threatened, its skin oozes a fast-setting natural glue that gums up ants and is being tested as a surgical adhesive. Read the guide →

Birds LC Limpkin Aramus guarauna The limpkin is a brown wading bird of American marshes that eats almost nothing but apple snails, extracting them without breaking the shell. Its wailing scream has spooked people for centuries. Read the guide →

Amphibians LC Water-holding Frog Cyclorana platycephala The water-holding frog of arid Australia stores water in its body, buries itself, and seals into a cocoon of shed skin to wait out drought. Desert peoples dug them up and squeezed them for a drink. Read the guide →

Amphibians CR Mountain Chicken Frog Leptodactylus fallax The mountain chicken is one of the world's largest frogs, a Caribbean giant once eaten as a national dish. Hunting, a volcano, and disease have cut it to a few hundred, almost all on one island. Read the guide →

Birds VU Wrybill Anarhynchus frontalis The wrybill is a small New Zealand plover and the only bird in the world with a bill that curves sideways, always to the right, which it uses to sweep under round riverbed stones for insect larvae. Read the guide →

Reptiles VU Alabama Red-Bellied Cooter Pseudemys alabamensis The Alabama red-bellied cooter is found nowhere on Earth outside a small stretch of coastal Alabama, making it the state reptile of the one place where it actually lives. Read the guide →

Amphibians NT Alabama Waterdog Necturus alabamensis The Alabama waterdog spends its entire life underwater with feathery external gills fanned out behind its head, found naturally in only a small handful of river systems in Alabama and adjacent states. Read the guide →

Invertebrates LC American Rubyspot Hetaerina americana The American rubyspot flashes a patch of deep ruby-red at the base of each wing, a colour bold enough to catch sunlight from across a stream and give this damselfly a striking appearance. Read the guide →

Birds LC Bell's Vireo Vireo bellii One subspecies of Bell's vireo declined so severely from habitat loss and cowbird parasitism that it was listed as federally endangered, while other subspecies of the species remain common elsewhere. Read the guide →

Fish LC Bigeye Shiner Notropis boops The bigeye shiner has unusually large eyes for a small minnow, an adaptation that lets it feed effectively in clear water even during the dim light of dawn and dusk. Read the guide →

Invertebrates LC Black Saddlebags Tramea lacerata The black saddlebags carries a bold dark patch at the base of each hindwing, like saddlebags slung over a horse, and travels farther and faster than almost any other dragonfly in North America. Read the guide →

Fish LC Blackbanded Darter Percina nigrofasciata The blackbanded darter is marked with a row of bold, dark, saddle-like blotches along its back, a pattern that helps it disappear against the dappled shade and gravel bottom of its home stream. Read the guide →

Fish LC Blackstripe Topminnow Fundulus notatus The blackstripe topminnow spends its life just beneath the water's surface, a bold dark stripe down its body making it one of the easiest small fish to identify in the streams it calls home. Read the guide →

Fish LC Bluefin Killifish Lucania goodei A breeding male bluefin killifish develops fins so vividly blue that the species is kept purely for its colour in home aquariums, despite being a small, unassuming wild fish most of the year. Read the guide →

Fish LC Bluespotted Sunfish Enneacanthus gloriosus The bluespotted sunfish is scattered with iridescent blue flecks across its dark body, a pattern so fine it looks hand-painted, and it thrives in slow, tannin-stained waters most other sunfish avoid. Read the guide →

Fish LC Bullhead Minnow Pimephales vigilax The bullhead minnow shares its common name with an entirely unrelated group of catfish, a small, tolerant minnow that thrives in murky, silty water many other minnow species avoid. Read the guide →

Reptiles LC Butler's Garter Snake Thamnophis butleri Butler's garter snake stays remarkably close to home for life, rarely straying far from where it was born, a stationary lifestyle unusual among North American garter snakes. Read the guide →

Invertebrates LC Calico Pennant Celithemis elisa The calico pennant carries a row of small heart-shaped red or yellow markings down the middle of its abdomen, a pattern distinctive enough among dragonflies to make identification almost immediate. Read the guide →

Invertebrates LC Common Whitetail Plathemis lydia A mature male common whitetail develops a body so heavily coated in chalky white powder it can look almost artificial, a striking transformation from the brown, patterned dragonfly it started as. Read the guide →

Fish LC Creek Chubsucker Erimyzon oblongus The creek chubsucker vacuums organic matter directly off the streambed with a downturned, sucker-shaped mouth, then sorts out the edible portion before spitting the rest back into the current. Read the guide →

Fish LC Cypress Darter Etheostoma proeliare The cypress darter is one of the smallest darters in North America, thriving in the slow, tannin-stained backwaters of cypress swamps that most of its fast-water-loving relatives avoid entirely. Read the guide →

Fish LC Deepwater Sculpin Myoxocephalus thompsonii The deepwater sculpin survives as a glacial relict, isolated in the cold depths of a handful of large northern lakes since the last ice age, unable to tolerate the warmer water separating populations. Read the guide →

Invertebrates LC Dragonhunter Hagenius brevistylus The dragonhunter is one of the largest dragonflies in North America, bold enough to attack and eat other dragonflies nearly its own size, including species most predators avoid entirely. Read the guide →

Fish LC Dusky Darter Percina sciera The dusky darter grows larger than many darter relatives, favoring deeper pools where it perches motionless on the bottom, propped up on its own pectoral fins between short bursts of movement. Read the guide →

Invertebrates LC Eastern Pondhawk Erythemis simplicicollis The eastern pondhawk is an aggressive, ground-perching dragonfly that attacks prey nearly as large as itself, including other dragonflies, and changes from bright green to powder blue as it matures. Read the guide →

Amphibians LC Everglades Dwarf Siren Pseudobranchus axanthus belli The Everglades dwarf siren is a tiny, eel-like salamander of Florida's marshes, so small and secretive that most people sharing its wetlands have never seen one despite it being locally common. Read the guide →

Reptiles LC False Map Turtle Graptemys pseudogeographica The false map turtle earned its odd name for resembling the common map turtle, distinguished by a bold yellow crescent behind each eye and a low, saw-toothed ridge running down its shell. Read the guide →

Fish LC Flagfish Jordanella floridae The flagfish is one of the few fish that will happily eat troublesome hair algae and blue-green algae most fish ignore, making it a favourite biological cleanup crew among aquarium keepers. Read the guide →

Fish LC Flier Sunfish Centrarchus macropterus The flier sunfish is the sole member of its own genus, a rounded, heavily barred fish carrying a dark eyespot near its dorsal fin that can help redirect a predator's strike away from vital organs. Read the guide →

Fish LC Goldstripe Darter Etheostoma parvipinne The goldstripe darter is one of the few darters that thrives in shallow, sluggish, sometimes barely-flowing seeps and spring runs, a habitat most of its fast-water-loving relatives avoid entirely. Read the guide →

Amphibians LC Green Treefrog Dryophytes cinereus The green treefrog is the official state amphibian of both Georgia and Louisiana, a bright frog often seen clinging to windows and porch lights at night, drawn by the insects gathering there. Read the guide →

Fish VU Guadalupe Bass Micropterus treculii The Guadalupe bass is found naturally nowhere on Earth except a handful of central Texas rivers, and it is now threatened by hybridization with introduced smallmouth bass stocked in the same waters. Read the guide →

Fish LC Least Killifish Heterandria formosa The least killifish is one of the smallest freshwater fish in North America, and despite its tiny size it gives birth to live young a couple at a time over an extended period rather than all at once. Read the guide →

Invertebrates LC Least Skipper Ancyloxypha numitor The least skipper flies with a weak, bobbing flutter low over grass, a flight style so different from most other skippers' fast, darting flight that it helps identify the species from a distance. Read the guide →

Reptiles LC Loggerhead Musk Turtle Sternotherus minor The loggerhead musk turtle carries an oversized head relative to its small shell, giving it a genuinely painful bite for such a small turtle and a look distinct from its musk turtle relatives. Read the guide →

Fish LC Longnose Sucker Catostomus catostomus The longnose sucker tolerates colder water than almost any other sucker in North America, found as far north as the Arctic Circle and surviving beneath ice through the harshest winters. Read the guide →

Birds LC Louisiana Waterthrush Parkesia motacilla The Louisiana waterthrush is one of the most reliable indicators of a healthy forest stream, since it depends so heavily on clean, fast-flowing water that its presence alone signals good conditions. Read the guide →

Reptiles VU Mexican Garter Snake Thamnophis eques The Mexican garter snake declined so sharply in Arizona from habitat loss and invasive fish and bullfrogs that it is now federally listed as threatened in the very state where it was once common. Read the guide →

Fish LC Mountain Redbelly Dace Chrosomus oreas A breeding male mountain redbelly dace turns a brilliant crimson along its belly and cheeks, one of the most vivid seasonal colour transformations of any small fish in Appalachian streams. Read the guide →

Amphibians LC Narrow-Striped Dwarf Siren Pseudobranchus striatus The narrow-striped dwarf siren is one of the smallest salamanders in North America, an eel-like amphibian with only tiny front legs that spends its entire life hidden among dense aquatic vegetation. Read the guide →

Amphibians LC Northern Dusky Salamander Desmognathus fuscus The northern dusky salamander holds its tail in a distinctive knife-edged, flattened profile, a subtle build that helps identify it among a large group of closely related stream-dwelling salamanders. Read the guide →

Fish LC Pearl Dace Margariscus margarita The pearl dace tolerates some of the coldest, most oxygen-poor water any small minnow regularly survives in, thriving in boggy northern streams and beaver ponds many other fish species avoid entirely. Read the guide →

Fish LC Pirate Perch Aphredoderus sayanus The pirate perch is the only living member of its family, a fish whose vent migrates forward to sit beneath its throat as it matures, an arrangement found in no other North American freshwater fish. Read the guide →

Birds LC Prothonotary Warbler Protonotaria citrea The prothonotary warbler is the only eastern warbler that nests inside tree cavities over water, a habit unusual enough among ground- and shrub-nesting warblers to earn it the nickname "swamp canary." Read the guide →

Fish LC Pugnose Minnow Opsopoeodus emiliae The pugnose minnow has a small, upturned mouth angled almost straight up, an adaptation suited to picking food from just below the water's surface rather than the bottom most minnows target. Read the guide →

Fish LC River Chub Nocomis micropogon The male river chub builds a nest mound of thousands of pebbles carried one at a time in his mouth, a structure so attractive to other fish that several minnow species rely on it to spawn. Read the guide →

Fish VU Roanoke Bass Ambloplites cavifrons The Roanoke bass survives naturally in only a handful of Virginia and North Carolina rivers, a close relative of the widespread rock bass now increasingly displaced by that same relative. Read the guide →

Fish LC Shadow Bass Ambloplites ariommus The shadow bass gets its name from lurking motionless in shaded cover along undercut banks and logs, ambushing prey that wanders too close rather than chasing anything down in open water. Read the guide →

Fish VU Shoal Bass Micropterus cataractae The shoal bass depends on rocky river shoals so specifically that dam construction across its native rivers has fragmented the species into isolated populations that can no longer reach one another. Read the guide →

Fish EN Shortnose Sturgeon Acipenser brevirostrum The shortnose sturgeon is one of the smallest sturgeons in North America, an armoured fish essentially unchanged for tens of millions of years, now endangered by dams blocking its spawning rivers. Read the guide →

Fish LC Slimy Sculpin Cottus cognatus The slimy sculpin has no swim bladder at all and coats itself in an unusually thick layer of mucus, an adaptation that lets it survive being frozen into surface ice during the coldest winters. Read the guide →

Birds NT Snowy Plover Charadrius nivosus The snowy plover is so pale that its speckled eggs and downy chicks nearly vanish against open sand, a camouflage so effective that beachgoers are the species' single biggest unintentional threat. Read the guide →

Amphibians CR South China Giant Salamander Andrias sligoi The South China giant salamander is the largest amphibian on Earth, historically nearly two metres long. Overhunting for luxury food has left it all but extinct in the wild. Read the guide →

Amphibians LC Southern Cricket Frog Acris gryllus The southern cricket frog produces a call so similar to two pebbles struck together that it gives the entire cricket frog group its name, despite being a true frog with no relation to crickets. Read the guide →

Reptiles LC Southern Watersnake Nerodia fasciata The southern watersnake is frequently mistaken for a venomous cottonmouth and killed on sight, despite being harmless and playing an important role controlling fish and amphibian populations. Read the guide →

Reptiles LC Speckled Kingsnake Lampropeltis holbrooki The speckled kingsnake is covered in so many yellow flecks that it earned the nickname salt-and-pepper snake, and like other kingsnakes it is largely immune to rattlesnake venom. Read the guide →

Birds LC Spotted Sandpiper Actitis macularius The spotted sandpiper reverses the usual roles seen in most birds, with females competing for mates and males left to incubate the eggs and raise the young almost entirely on their own. Read the guide →

Fish LC Starhead Topminnow Fundulus dispar The starhead topminnow carries a small star-shaped patch of light scales between its eyes, a marking that gives the species its name and helps separate it from similarly shaped topminnow relatives. Read the guide →

Birds LC Sungrebe Heliornis fulica The sungrebe is a secretive Central American waterbird with a trick found in no other bird — the male carries his tiny chicks in a pair of skin pouches under his wings, even in flight. Read the guide →

Fish LC Suwannee Bass Micropterus notius The Suwannee bass is found naturally in only two river systems, both in northern Florida and southern Georgia, making it one of the most geographically restricted black bass species in North America. Read the guide →

Birds LC Swamp Sparrow Melospiza georgiana The swamp sparrow forages by wading directly into shallow marsh water, sometimes submerging its head entirely to snatch aquatic insects most other sparrows would never attempt to reach. Read the guide →

Fish LC Telescope Shiner Notropis telescopus The telescope shiner has unusually large, forward-directed eyes that give the species its common name, an adaptation thought to help it track fast-drifting insect prey in clear, flowing water. Read the guide →

Fish LC Torrent Sculpin Cottus rhotheus The torrent sculpin thrives in the fast, turbulent riffle water its name suggests, holding its position on the streambed with a body built to sink and stay put rather than fight the current. Read the guide →

Invertebrates LC Twelve-Spotted Skimmer Libellula pulchella The twelve-spotted skimmer carries exactly twelve dark spots across its wings, a precise, countable pattern that makes it one of the easiest dragonflies in North America to identify from a distance. Read the guide →

Invertebrates LC Viceroy Butterfly Limenitis archippus The viceroy butterfly was long believed to be a harmless mimic copying the toxic monarch for protection, until research showed the viceroy is itself genuinely distasteful too. Read the guide →

Fish LC Warpaint Shiner Luxilus coccogenis A breeding male warpaint shiner develops streaks of vivid red and orange across its head and fins, a striking seasonal pattern bold enough to have earned the species its distinctive common name. Read the guide →

Fish LC White Crappie Pomoxis annularis The white crappie tolerates murkier, more turbid water better than its close relative the black crappie, and a count of dorsal fin spines is the most reliable way anglers separate the two. Read the guide →

Birds LC Alder Flycatcher Empidonax alnorum The alder flycatcher was only recognized as its own species after researchers realized its "free-beer" song never overlaps with its nearly identical relative, the willow flycatcher. Read the guide →

Fish EN American Eel Anguilla rostrata The American eel lives most of its life in fresh water, then travels to the Sargasso Sea to breed and die, the exact reverse of a salmon's migration. Read the guide →

Amphibians NT Atlantic Coast Leopard Frog Lithobates kauffeldi The Atlantic Coast leopard frog was hiding in plain sight around New York City for decades, only formally recognized as its own species in 2014 after its distinct call gave it away. Read the guide →

Fish LC Banded Sunfish Enneacanthus obesus The banded sunfish shares its acidic blackwater habitat with the more boldly patterned blackbanded sunfish, wearing a softer, more diffuse version of the same vertical striping. Read the guide →

Fish LC Bantam Sunfish Lepomis symmetricus The bantam sunfish is one of the least commonly seen members of its genus, confined to swampy Mississippi River floodplain backwaters that most anglers rarely fish. Read the guide →

Fish NT Blackbanded Sunfish Enneacanthus chaetodon The blackbanded sunfish wears bold vertical black bars over a silvery body, an ornamental pattern striking enough to make it a favorite in the home aquarium trade. Read the guide →

Fish LC Blacknose Dace Rhinichthys atratulus The blacknose dace is one of the most reliable indicators of a healthy small stream, thriving in clean, cool water and disappearing once pollution or warming pushes conditions too far. Read the guide →

Amphibians LC Boreal Chorus Frog Pseudacris maculata The boreal chorus frog calls before almost any other frog each spring, sometimes trilling from beneath a thin layer of ice, and it can even survive being partly frozen solid during a late cold snap. Read the guide →

Reptiles LC Brazos Water Snake Nerodia harteri The Brazos water snake exists naturally only along a single Texas river system, favoring rocky, fast-flowing riffles over the still water most water snakes prefer. Read the guide →

Fish LC Brindled Madtom Noturus miurus The brindled madtom carries a mottled, saddle-like blotch pattern along its back, and like its close relatives it packs a genuinely painful venomous sting into a fish barely longer than a finger. Read the guide →

Amphibians LC Chamberlain's Dwarf Salamander Eurycea chamberlaini Chamberlain's dwarf salamander was only recognized as its own species after genetic study split it away from the wider dwarf salamander group it had long been lumped into. Read the guide →

Fish NT Coho Salmon Oncorhynchus kisutch The coho salmon spends far longer as a freshwater juvenile than most Pacific salmon before heading to sea, and breeding males develop a distinctive hooked jaw. Read the guide →

Reptiles LC Concho Water Snake Nerodia paucimaculata The Concho water snake exists only along two Texas rivers, and its recovery from federal protection to delisting stands as one of the rarer conservation success stories. Read the guide →

Fish LC Dollar Sunfish Lepomis marginatus The dollar sunfish is named for its small, round, coin-like shape, one of the smallest sunfish species and easy to overlook in the quiet, vegetated waters it prefers. Read the guide →

Amphibians LC Dwarf Waterdog Necturus punctatus The dwarf waterdog is the smallest of the North American waterdogs, keeping its feathery external gills for life while rarely growing large enough to draw much attention. Read the guide →

Reptiles EN Eastern Fox Snake Pantherophis gloydi The eastern fox snake is a harmless constrictor so often mistaken for a rattlesnake, thanks to its coppery head and rattlesnake-mimicking tail vibration, that it is regularly killed by mistake. Read the guide →

Birds LC Eastern Kingbird Tyrannus tyrannus The eastern kingbird fearlessly attacks hawks and crows many times its own size near its nest, and hides a fiery orange-red crown patch it flashes only during these confrontations. Read the guide →

Amphibians LC Iberian Water Frog Pelophylax perezi The Iberian water frog stays active and calling through the hottest, driest Iberian summers that send most other frogs into hiding, thriving in irrigation ditches and farm ponds most amphibians avoid. Read the guide →

Fish LC Longnose Dace Rhinichthys cataractae The longnose dace has a flattened head and overhanging snout built to hug the bottom of the fastest, most turbulent riffles, letting it feed exactly where most other small fish cannot. Read the guide →

Fish LC Mud Sunfish Acantharchus pomotis The mud sunfish tolerates the acidic, tannin-stained blackwater swamps of the coastal plain, often sitting motionless on the bottom rather than swimming like most of its more active relatives. Read the guide →

Fish LC Ninespine Stickleback Pungitius pungitius The ninespine stickleback rarely has exactly nine spines despite its name, and males build and guard a nest the way few fish parents ever do. Read the guide →

Birds LC Northern Parula Setophaga americana The northern parula builds its nest almost exclusively inside hanging clumps of Spanish moss or beard lichen, tucking the whole structure into a natural curtain most predators never think to search. Read the guide →

Amphibians DD One-Toed Amphiuma Amphiuma pholeter The one-toed amphiuma is the smallest and least-seen of the three amphiuma species, spending nearly its entire life burrowed into wet organic muck. Read the guide →

Reptiles LC Ouachita Map Turtle Graptemys ouachitensis Female Ouachita map turtles grow heads and jaws so much larger than males that the two sexes eat different diets, with only females strong enough to crush hard-shelled mussels and snails. Read the guide →

Fish LC Ozark Sculpin Cottus hypselurus The Ozark sculpin lives only in cold, spring-fed Ozark streams, and was only recognized as its own species after genetic study separated it from a similar-looking relative. Read the guide →

Fish EN Pallid Sturgeon Scaphirhynchus albus The pallid sturgeon may not reach sexual maturity until its twenties, and dam-driven habitat loss has made it one of the most endangered fish in North America. Read the guide →

Birds LC Red-Shouldered Hawk Buteo lineatus The red-shouldered hawk hunts from within dense forest rather than open sky, unusual for its family, and its loud call is so distinctive that blue jays are known to mimic it. Read the guide →

Amphibians DD Reticulated Siren Siren reticulata The reticulated siren was only formally described in 2018, one of the largest new vertebrate species named in the United States in decades, despite a striking net-like pattern. Read the guide →

Amphibians LC Rio Grande Chirping Frog Eleutherodactylus cystignathoides The Rio Grande chirping frog skips the tadpole stage entirely, hatching directly into a tiny froglet, and has hitchhiked in nursery plants far beyond its native range. Read the guide →

Reptiles LC River Cooter Pseudemys concinna The river cooter is one of the few reptiles known to communicate with its mouth completely underwater, using a face-to-face vibrating claw display that plays out entirely below the surface. Read the guide →

Fish LC Shorthead Redhorse Moxostoma macrolepidotum The shorthead redhorse vacuums up mouthfuls of river-bottom sediment and sorts out edible invertebrates before spitting the rest back out, a feeding style shared across its entire sucker family. Read the guide →

Fish LC Snail Darter Percina tanasi The snail darter became a household name in the 1970s when its discovery in a Tennessee river halted a federal dam, in one of the most famous endangered species court battles in US history. Read the guide →

Fish LC Southern Redbelly Dace Chrosomus erythrogaster The southern redbelly dace turns a brilliant, fiery red along its belly during breeding season, one of the most vivid colour transformations of any small North American minnow. Read the guide →

Fish LC Spotted Sucker Minytrema melanops The spotted sucker carries a dark spot at the base of nearly every scale, together forming faint rows that run the length of its body. Read the guide →

Amphibians LC Striped Chorus Frog Pseudacris nigrita The striped chorus frog breeds in shallow, temporary coastal-plain pools, and its males call in such dense choruses that individual calls blur into a single continuous buzzing wall of sound. Read the guide →

Reptiles LC Striped Mud Turtle Kinosternon baurii The striped mud turtle can seal its shell more completely than most other mud turtles, closing itself away almost entirely thanks to a double-hinged plastron. Read the guide →

Fish LC Striped Shiner Luxilus chrysocephalus A breeding male striped shiner develops a rosy-pink flush and rows of hard bumps across its head, transforming from an unremarkable silver minnow into one of the more colourful fish in its stream. Read the guide →

Amphibians LC Stripeless Tree Frog Hyla meridionalis The stripeless tree frog lacks the dark side stripe nearly every other European tree frog carries, a single missing marking that gives it both its common name and easiest identification feature. Read the guide →

Fish LC Swamp Darter Etheostoma fusiforme The swamp darter is one of the very few darter species that thrives in still, weedy, low-oxygen swamp water, a habitat almost every other member of its fast-water-loving family avoids entirely. Read the guide →

Fish LC Tadpole Madtom Noturus gyrinus The tadpole madtom is named for its stout, rounded body shape that resembles a tadpole rather than a typical catfish, and it is the most widely distributed madtom species in North America. Read the guide →

Amphibians NT Texas Salamander Eurycea neotenes The Texas salamander never grows up in the usual sense, keeping its larval gills for life within the same Edwards Aquifer springs that support several of its more famous cave-dwelling relatives. Read the guide →

Amphibians EX Vegas Valley Leopard Frog Lithobates fisheri The Vegas Valley leopard frog once lived only in the desert springs beneath what is now Las Vegas, and disappeared for good sometime around the 1940s. Read the guide →

Birds LC Vermilion Flycatcher Pyrocephalus rubinus The male vermilion flycatcher performs a fluttering, sky-facing display flight while singing, showing off a scarlet-red body that ranks among the most vivid colors of any North American flycatcher. Read the guide →

Amphibians LC White-Lipped Tree Frog Litoria infrafrenata The white-lipped tree frog is the largest tree frog on Earth, identifiable at a glance by the crisp white stripe running along its lower jaw, and its deep, dog-like bark is unlike any other frog call. Read the guide →

Birds LC Willow Flycatcher Empidonax traillii The willow flycatcher looks almost identical to its sibling species the alder flycatcher, and the two are reliably told apart only by their completely different songs. Read the guide →

Birds LC Wilson's Warbler Cardellina pusilla Wilson's warbler is a tiny, active songbird with a neat black cap, and its western populations have declined so sharply that it is one of the most closely tracked warblers in bird-banding studies. Read the guide →

Fish LC Yellow Bass Morone mississippiensis The yellow bass looks nearly identical to the white bass, but its dark side stripes are often broken and offset rather than running in straight, unbroken lines. Read the guide →

Birds LC Yellow Warbler Setophaga petechia The yellow warbler responds to a cowbird egg in its nest by building an entirely new nest floor right on top of it, sometimes stacking several buried layers in a single season. Read the guide →

Reptiles LC Alabama Map Turtle Graptemys pulchra The Alabama map turtle's females grow dramatically wider heads than males, an adaptation that lets them crush thick-shelled mussels the narrower-jawed males of the same species cannot manage. Read the guide →

Amphibians EN Austin Blind Salamander Eurycea waterlooensis The Austin blind salamander lives only within the deep aquifer water beneath a single Texas spring complex and was not formally described until 2001. Read the guide →

Fish LC Black Bullhead Ameiurus melas The black bullhead tolerates water so poor in oxygen that most other fish would suffocate, and its young form a tight, parent-guarded schooling ball. Read the guide →

Fish LC Black Redhorse Moxostoma duquesnei The black redhorse requires cleaner, faster-flowing water than most of its redhorse relatives, making it one of the more reliable indicators of good stream health within its range. Read the guide →

Amphibians EN Black Warrior Waterdog Necturus alabamensis The Black Warrior waterdog survives only in one Alabama river already altered by dams and pollution, one of the more critically endangered aquatic salamanders in North America. Read the guide →

Invertebrates LC Blue Dasher Pachydiplax longipennis The blue dasher perches with its wings angled forward and down, a distinctive posture that helps it regulate body temperature by controlling how much sunlight reaches its body. Read the guide →

Reptiles LC Brown Basilisk Basiliscus vittatus The brown basilisk can sprint across the surface of water on its hind legs alone, slapping specialized fringed toes down fast enough to avoid sinking before momentum runs out. Read the guide →

Amphibians VU Comal Blind Salamander Eurycea tridentifera The Comal blind salamander spends its entire life underground in Texas cave water, with no eyes, no pigment, and external gills it never outgrows. Read the guide →

Birds LC Common Yellowthroat Geothlypis trichas The male common yellowthroat wears a bold black mask across the eyes, and females appear to select mates partly based on the size and sharpness of that exact facial marking. Read the guide →

Fish LC Emerald Shiner Notropis atherinoides The emerald shiner forms schools numbering in the millions in large lakes and rivers, making it one of the most important single forage fish supporting entire freshwater food webs. Read the guide →

Reptiles LC Escambia Map Turtle Graptemys ernsti The Escambia map turtle was only formally recognized as its own species in 1992, split from a similar-looking relative after closer study revealed genuinely distinct shell and jaw features. Read the guide →

Amphibians VU Florida Bog Frog Lithobates okaloosae The Florida bog frog is found in only a small handful of acidic seepage streams within a single county, one of the most geographically restricted frog species in the United States. Read the guide →

Fish LC Golden Redhorse Moxostoma erythrurum The golden redhorse takes its name from a brassy sheen and reddish fins, one of the more common and adaptable members of a sucker group generally sensitive to poor water. Read the guide →

Invertebrates LC Halloween Pennant Celithemis eponina The Halloween pennant perches loosely at the tip of tall grass or reeds, flagging back and forth in the breeze like a small orange-and-black pennant flying from a pole. Read the guide →

Fish LC Margined Madtom Noturus insignis The margined madtom carries a dark border along its fins that gives the species its name, and like its madtom relatives it delivers a mild but genuinely irritating sting if handled carelessly. Read the guide →

Reptiles LC Mimic Glass Lizard Ophisaurus mimicus The mimic glass lizard closely resembles its more common slender glass lizard relative, a similarity close enough that the species went undescribed for years. Read the guide →

Reptiles LC Mississippi Map Turtle Graptemys pseudogeographica kohnii The Mississippi map turtle carries a small crescent-shaped mark behind each eye, a feature that stands out against the fine pattern of light lines covering the rest of the shell and skin. Read the guide →

Amphibians VU Neuse River Waterdog Necturus lewisi The Neuse River waterdog is found only within two river systems in North Carolina, remaining fully aquatic and gilled for its entire life while population numbers continue a long, slow decline. Read the guide →

Fish LC Nile Perch Lates niloticus The Nile perch is a two-metre African predator. Stocked into Lake Victoria last century, it helped drive hundreds of the lake's unique cichlids to extinction and built a huge export fishery. Read the guide →

Fish LC Quillback Carpiodes cyprinus The quillback carries a tall, sharply pointed dorsal fin whose leading ray extends into a long, quill-like filament, a feature striking enough to give the species its common name. Read the guide →

Reptiles LC Razorback Musk Turtle Sternotherus carinatus The razorback musk turtle carries a distinctly high, sharply keeled shell unlike the flatter shells of its musk turtle relatives, a shape pronounced enough to give the species its common name. Read the guide →

Amphibians LC Rio Grande Leopard Frog Lithobates berlandieri The Rio Grande leopard frog tolerates warmer, more arid conditions than most leopard frog relatives, thriving in irrigation canals and stock tanks across otherwise dry border country. Read the guide →

Fish LC River Redhorse Moxostoma carinatum The river redhorse has unusually large, molar-like teeth in its throat capable of crushing snail and mussel shells whole, a feeding tool more powerful than most of its redhorse relatives possess. Read the guide →

Fish LC Sailfin Molly Poecilia latipinna Male sailfin mollies raise a tall, sail-like dorsal fin to compete for female attention, a display so central that smaller, subordinate males rely on sneaking instead. Read the guide →

Amphibians EN Sierra Nevada Yellow-Legged Frog Rana sierrae The Sierra Nevada yellow-legged frog has vanished from the vast majority of its historical high-elevation lakes, largely because trout introduced for sport fishing prey heavily on its tadpoles. Read the guide →

Fish LC Silver Redhorse Moxostoma anisurum The silver redhorse is among the largest members of the redhorse group, with a silvery body and grey rather than red fins, a plainer look than several of its more brightly finned relatives. Read the guide →

Birds LC Song Sparrow Melospiza melodia The song sparrow varies so dramatically across North America that some three dozen recognized subspecies exist, ranging from pale desert forms to notably large, dark birds of the Aleutian Islands. Read the guide →

Birds LC Southern Carmine Bee-eater Merops nubicoides The southern carmine bee-eater is a brilliant red African bird that nests in huge colonies in riverbanks, catches bees in flight, and rides on bustards and antelopes to flush insects. Read the guide →

Amphibians NT Southern Crawfish Frog Lithobates areolatus areolatus The southern crawfish frog spends nearly all its life inside an abandoned crayfish burrow, emerging mainly to breed, a level of dependence on another animal's construction work rare among frogs. Read the guide →

Amphibians EN Southern Dusky Salamander Desmognathus auriculatus The southern dusky salamander vanished from most of its range for reasons only partly understood, one of the more mysterious amphibian declines in the southeastern US. Read the guide →

Fish LC Stonecat Noturus flavus The stonecat delivers a genuinely painful sting from venom glands at the base of its pectoral and dorsal spines, a defense unusual among the otherwise mild madtom catfish it belongs to. Read the guide →

Amphibians CR Table Mountain Ghost Frog Heleophryne rosei The Table Mountain ghost frog lives only in a few fast streams above Cape Town. It climbs wet vertical rock on sticky toes, and its tadpoles grip boulders in the torrent with a sucker mouth. Read the guide →

Reptiles LC Texas Map Turtle Graptemys versa The Texas map turtle is found only within a single Texas river system, and females grow a noticeably wider, crushing jaw than males, letting them tackle snails and mussels males can't manage. Read the guide →

Fish LC White Bass Morone chrysops The white bass forms surface-churning feeding frenzies while chasing shad in open water, and its hybrid with the striped bass is stocked widely as the wiper. Read the guide →

Amphibians CR Hula Painted Frog Latonia nigriventer The Hula painted frog was declared extinct in 1996, rediscovered in an Israeli marsh in 2011, and then found to be the only living member of a frog genus otherwise known only from fossils. Read the guide →

Amphibians EW Kihansi Spray Toad Nectophrynoides asperginis The Kihansi spray toad lived only in the mist of one Tanzanian waterfall until a dam dried its home. Saved by a last-minute airlift to US zoos, it has since been bred and returned to the wild. Read the guide →

Fish CR Mekong Giant Catfish Pangasianodon gigas The Mekong giant catfish is one of the largest freshwater fish on Earth, reaching three metres and 300 kg, yet it is toothless and eats plants. Dams and overfishing have made it Critically Endangered. Read the guide →

Reptiles VU Sailfin Dragon Hydrosaurus pustulatus The sailfin dragon is a metre-long Southeast Asian lizard with a tall skin-covered sail on its tail. It lives along rivers, swims and dives well, and its young can sprint across the water surface. Read the guide →

Invertebrates LC Common Green Darner Anax junius The common green darner migrates south in autumn much like a bird, and the generation that returns north the following spring is actually the grandchildren of the ones that made the original journey. Read the guide →

Amphibians LC Eastern Banjo Frog Limnodynastes dumerilii The eastern banjo frog is a burrowing Australian ground frog whose short, resonant bonk call sounds like a plucked banjo string, and a pond full of calling males sounds like a band tuning up. Read the guide →

Invertebrates LC Ebony Jewelwing Calopteryx maculata The ebony jewelwing flies with a slow, fluttering wingbeat, its solid black wings and metallic green body making it look more like a flying jewel than an insect. Read the guide →

Fish LC Elephantnose Fish Gnathonemus petersii The elephantnose fish navigates muddy African rivers by generating a weak electric field and reading the distortions in it. It has one of the largest brains for its size of any animal. Read the guide →

Mammals VU Fishing Cat Prionailurus viverrinus The fishing cat is a stocky, water-loving wild cat of South and Southeast Asian wetlands that dives and swims after fish, scoops them from the water with a paw, and has partly webbed feet. Read the guide →

Amphibians CR Lake Patzcuaro Salamander Ambystoma dumerilii The Lake Patzcuaro salamander is a gilled, permanently aquatic axolotl relative from one Mexican highland lake, kept from extinction partly by nuns who have bred it for generations. Read the guide →

Birds LC Northern Jacana Jacana spinosa The northern jacana walks on floating lily pads with enormous long toes. Females are larger, hold territories of several males, and leave each male to build the nest and raise the chicks alone. Read the guide →

Fish NE Payara Hydrolycus scomberoides The payara, or vampire fish, is a powerful Amazon predator with two long fangs in its lower jaw that slot into sockets in its skull and impale smaller fish, including piranhas, that it swallows whole. Read the guide →

Fish LC Rosyface Shiner Notropis rubellus The rosyface shiner's breeding males flush a vivid rosy-red wash across the head and body, a seasonal display bright enough to stand out clearly even among a large, fast-moving school. Read the guide →

Fish LC Silverjaw Minnow Notropis buccatus The silverjaw minnow has a distinctly fleshy, overhanging snout used to root through sand and gravel, and a translucent silvery patch on the lower jaw that gives the species its common name. Read the guide →

Reptiles NE Spiny Bush Viper Atheris hispida The spiny bush viper is a small African tree viper whose strongly keeled, upturned scales stick out to give it a bristly, almost dragon-like coat. It ambushes frogs and small mammals at night. Read the guide →

Fish LC Spotfin Shiner Cyprinella spiloptera The spotfin shiner tolerates murkier, more disturbed water than many of its minnow relatives, often becoming one of the most common small fish in streams degraded enough to push pickier species out. Read the guide →

Amphibians LC Three-Lined Salamander Eurycea guttolineata The three-lined salamander has a notably long tail making up well over half its total length, an exaggerated proportion that helps it wriggle rapidly through dense leaf litter and grass. Read the guide →

Birds LC American Avocet Recurvirostra americana The American avocet sweeps its long, distinctly upturned bill side to side through shallow water like a scythe, feeling for prey rather than looking for it directly. Read the guide →

Fish LC Arctic Char Salvelinus alpinus The Arctic char lives further north than any other freshwater fish on Earth, with some populations spawning in near-freezing water and others trapped in lakes since the last ice age. Read the guide →

Fish EN Australian Lungfish Neoceratodus forsteri The Australian lungfish is a heavy, olive-scaled river fish of Queensland that has barely changed in 100 million years and can breathe air through a single lung when its pool runs low on oxygen. Read the guide →

Fish LC Banded Killifish Fundulus diaphanus The banded killifish forms large, tight schools that swim just beneath the surface of clear, weedy shallows, its narrow vertical bars breaking up the outline of any single fish within the group. Read the guide →

Fish LC Banded Sculpin Cottus carolinae The banded sculpin favours cool spring-fed streams and cave-adjacent waters of the Ozark and Appalachian highlands, its dark banding blending into the same gravel it hides against. Read the guide →

Fish LC Black Crappie Pomoxis nigromaculatus The black crappie carries irregular black speckling rather than the vertical bars of its close relative, and its extra dorsal spines are the most reliable way to tell the two apart. Read the guide →

Reptiles LC Black-Necked Garter Snake Thamnophis cyrtopsis The black-necked garter snake carries a pair of dark blotches just behind its head, and it sticks closer to rocky canyon streams than almost any other garter snake in its range. Read the guide →

Birds LC Black-Necked Stilt Himantopus mexicanus The black-necked stilt wades on the longest legs relative to body size of almost any bird, and a pair defending a nest will fake a broken wing to lure a predator far away from their eggs. Read the guide →

Fish LC Blackside Darter Percina maculata The blackside darter carries a row of squarish dark blotches down its flank, a pattern that helps it disappear against gravel and sand in the moderate-current streams it prefers. Read the guide →

Amphibians DD Blanco Blind Salamander Eurycea robusta The Blanco blind salamander is known from only a single well and has not been documented in the wild since its initial discovery, making it one of the most poorly known amphibians in North America. Read the guide →

Fish LC Bluebreast Darter Etheostoma camurum The bluebreast darter's breeding males flush a vivid blue chest and orange-red fins, a display so demanding on clean, fast-flowing water that the species disappears quickly once a stream is polluted. Read the guide →

Fish LC Bluehead Chub Nocomis leptocephalus The bluehead chub builds a large gravel mound nest that other minnow species deliberately spawn over, making this one fish's construction project a shared nursery for an entire local fish community. Read the guide →

Amphibians LC Brimley's Chorus Frog Pseudacris brimleyi Brimley's chorus frog is confined to a narrow strip of the Atlantic coastal plain, calling from grassy ditches with a rasping call easily confused with its more widespread upland relative. Read the guide →

Fish LC Brown Bullhead Ameiurus nebulosus The brown bullhead can taste food before it even reaches its mouth, using sensitive barbels and skin covered in taste buds, and it tolerates water so low in oxygen it would kill most other fish. Read the guide →

Fish VU Bull Trout Salvelinus confluentus The bull trout needs colder, cleaner water than any of its relatives, and unlike most trout it keeps eating other fish as an adult instead of switching mainly to invertebrates. Read the guide →

Amphibians LC Cajun Chorus Frog Pseudacris fouquettei The Cajun chorus frog was only recently recognized as its own species, split from the upland chorus frog after genetic evidence showed the western Gulf Coast population was genuinely distinct. Read the guide →

Fish EN Candy Darter Etheostoma osburni The candy darter shows some of the most vivid coloring of any North American freshwater fish, and hybridization with an introduced relative threatens to erase its genetics. Read the guide →

Amphibians VU Cascade Caverns Salamander Eurycea latitans The Cascade Caverns salamander lives entirely within cave streams and springs of the Texas Hill Country, sometimes retaining tiny remnants of eyes despite spending its whole life in total darkness. Read the guide →

Reptiles LC Checkered Garter Snake Thamnophis marcianus The checkered garter snake tolerates heat and drought better than most of its garter snake relatives, surviving comfortably in arid habitat that would leave many close relatives struggling. Read the guide →

Fish LC Christmas Darter Etheostoma hopkinsi The Christmas darter's breeding males flash festive red and green bands along the body, a combination bright enough to have given this small Southeastern fish its holiday-themed common name. Read the guide →

Amphibians EN Comal Springs Salamander Eurycea sp. The Comal Springs salamander survives entirely within one Texas spring system, spending much of its life deep in the Edwards Aquifer that feeds it. Read the guide →

Fish LC Common Shiner Luxilus cornutus The common shiner's breeding males flush a vivid rosy pink along the sides and grow small horn-like bumps on the head, among the most colourful transformations of any widespread North American minnow. Read the guide →

Reptiles LC Cottonmouth Agkistrodon piscivorus The cottonmouth, or water moccasin, is a thick-bodied semi-aquatic pit viper of the southeastern United States that gapes to flash the white lining of its mouth when it feels cornered. Read the guide →

Reptiles CR Cuban Crocodile Crocodylus rhombifer The Cuban crocodile is a small, agile, boldly speckled crocodile that survives only in two Cuban swamps. It leaps, walks on land with ease, and is one of the most endangered crocodiles on Earth. Read the guide →

Amphibians EN Dixie Valley Toad Anaxyrus williamsi The Dixie Valley toad survives entirely within a single square mile of geothermal wetland in the Nevada desert, one of the smallest ranges of any amphibian species on Earth. Read the guide →

Amphibians LC Dwarf Salamander Eurycea quadridigitata The dwarf salamander has only four toes on its hind feet rather than the usual five found on most salamanders, a subtle but reliable feature for identifying this tiny southeastern species. Read the guide →

Fish LC Flier Centrarchus macropterus The flier carries a dark eyespot on its dorsal fin and unusually long, rounded fins for a sunfish relative, favoring sluggish, heavily vegetated swamps of the southeastern coastal plain. Read the guide →

Reptiles LC Florida Softshell Turtle Apalone ferox The Florida softshell turtle breathes through a long, flexible, snorkel-like nose while staying almost entirely buried in mud, and it bites hard enough to make handling one a genuinely bad idea. Read the guide →

Amphibians VU Georgetown Salamander Eurycea naufragia The Georgetown salamander survives only in a handful of springs and caves near one Texas city, dependent on groundwater the city's own growth increasingly threatens. Read the guide →

Reptiles VU Giant Garter Snake Thamnophis gigas The giant garter snake has lost most of its original California wetland habitat to agriculture, now surviving largely in irrigation canals and rice fields rather than the marshes it once depended on. Read the guide →

Fish VU Gilt Darter Percina evides The gilt darter has vanished from large parts of its range as dams and sediment transformed the fast, clean riffles it needs, though scattered strongholds remain. Read the guide →

Reptiles LC Glossy Crayfish Snake Regina rigida The glossy crayfish snake stays hidden by day beneath mats of vegetation in southeastern swamps, emerging after dark to hunt for crayfish freshly emerged from their molt. Read the guide →

Birds LC Glossy Ibis Plegadis falcinellus The glossy ibis appears dark and unremarkable from a distance, but breeding adults catch the light in an iridescent sheen of bronze, purple, and green rarely appreciated until seen up close. Read the guide →

Reptiles LC Green Water Snake Nerodia cyclopion The green water snake is a large, heavy-bodied non-venomous species that basks in numbers along southern swamps and bayous, frequently mistaken for the venomous cottonmouth it shares habitat with. Read the guide →

Fish LC Iowa Darter Etheostoma exile The Iowa darter tolerates colder water than most of its darter relatives, and breeding males flush a vivid blue-green and orange-red pattern in glacial lakes and cool northern streams. Read the guide →

Amphibians VU Jollyville Plateau Salamander Eurycea tonkawae The Jollyville Plateau salamander lives in springs and caves near fast-growing Austin, Texas, one of the few salamanders whose survival depends directly on urban groundwater management. Read the guide →

Amphibians NT Junaluska Salamander Eurycea junaluska The Junaluska salamander is so rarely encountered that its adult form went undescribed for years after its larvae were already known to science, a genuine reversal of how most species get discovered. Read the guide →

Amphibians VU Kaiser's Spotted Newt Neurergus kaiseri Kaiser's spotted newt is a black, white and orange salamander from a few mountain streams in western Iran, nearly bought to extinction by collectors through the online pet trade. Read the guide →

Fish LC Lake Trout Salvelinus namaycush The lake trout retreats into the deepest, coldest water of a lake as the seasons warm, and some individuals in the coldest northern lakes have been documented living for over a century. Read the guide →

Fish LC Least Darter Etheostoma microperca The least darter ranks among the smallest freshwater fish in North America, small enough that its entire life plays out within a single quiet, weedy pool most anglers would never think to look in. Read the guide →

Amphibians VU Lowland Leopard Frog Lithobates yavapaiensis The lowland leopard frog survives in desert streams and springs of the arid Southwest, an unusually dry range for a leopard frog, and has declined sharply from introduced predators and disease. Read the guide →

Amphibians NT Mabee's Salamander Ambystoma mabeei Mabee's salamander survives in a narrow strip of the Atlantic coastal plain, breeding in temporary forest ponds that dry up completely for much of the year. Read the guide →

Fish NE Madtom Noturus spp. The madtom is among the very few catfish genera with a genuine venomous sting, delivered through grooved spines that make this small, secretive fish surprisingly painful to mishandle. Read the guide →

Amphibians LC Many-Lined Salamander Stereochilus marginatus The many-lined salamander stays aquatic its entire life, never fully transforming into a land-dwelling adult, and can be found hiding among sphagnum moss in Carolina bay wetlands. Read the guide →

Fish LC Mottled Sculpin Cottus bairdii The mottled sculpin has no swim bladder at all, so it simply sinks and stays pinned to the streambed, camouflaged so effectively it can vanish in plain sight. Read the guide →

Fish LC Mummichog Fundulus heteroclitus The mummichog tolerates swings in salinity, temperature, and oxygen that would kill most fish outright, and its genetic hardiness has made it one of the most studied fish in laboratory research. Read the guide →

Invertebrates NE Mysid Mysida The mysid carries its developing young in a pouch beneath the body just like a marsupial, earning it the nickname opossum shrimp despite not being a true shrimp at all. Read the guide →

Fish LC Northern Hogsucker Hypentelium nigricans The northern hogsucker roots along stream bottoms with a hog-like snout, flipping rocks for insect larvae, a style so effective other fish trail behind to catch what it stirs loose. Read the guide →

Amphibians LC Northern Red-Legged Frog Rana aurora The northern red-legged frog was once considered the same species as the California red-legged frog, until researchers split them apart based on genetic and physical differences. Read the guide →

Amphibians LC Northwestern Salamander Ambystoma gracile The northwestern salamander produces a mild skin toxin as defense, and some populations never leave the water at all, remaining gilled and aquatic for their entire adult lives. Read the guide →

Fish LC Orangespotted Sunfish Lepomis humilis The orangespotted sunfish tolerates murky, silty prairie streams better than most of its relatives, often becoming the dominant small sunfish where turbid water pushes pickier species out. Read the guide →

Reptiles LC Red-Bellied Snake Storeria occipitomaculata The red-bellied snake feeds almost entirely on slugs, and when frightened some individuals curl back their upper lip in a strange, nervous-looking grin rather than trying to strike. Read the guide →

Fish LC Redbreast Sunfish Lepomis auritus The redbreast sunfish favours flowing streams and rivers more than the still water most of its sunfish relatives prefer, and breeding males flush a vivid orange-red across the breast. Read the guide →

Fish LC Redear Sunfish Lepomis microlophus The redear sunfish carries specialised crushing teeth in its throat built specifically for cracking snail shells, a diet distinctive enough among sunfish to earn it the nickname shellcracker. Read the guide →

Fish LC Redline Darter Etheostoma rufilineatum The redline darter's breeding males develop thin red streaks running down the body and bright turquoise fins, a combination that makes it one of the more colorful small fish of Appalachian streams. Read the guide →

Amphibians VU Salado Salamander Eurycea chisholmensis The Salado salamander survives only around a small cluster of springs feeding one Texas creek, a population so localized that a single prolonged drought could threaten the entire species at once. Read the guide →

Amphibians VU San Marcos Salamander Eurycea nana The San Marcos salamander lives only at the headwater springs of the San Marcos River, one of the smallest members of its genus and entirely dependent on a single spring system's flow. Read the guide →

Fish LC Sauger Sander canadensis The sauger tolerates muddier, more turbid water than its close relative the walleye, and its heavily spotted dorsal fin is the clearest way to tell the two fish apart. Read the guide →

Fish LC Shortnose Gar Lepisosteus platostomus The shortnose gar can gulp air at the surface using a swim bladder that works like a primitive lung, letting it survive in water too low in oxygen for most other fish. Read the guide →

Fish LC Smallmouth Bass Micropterus dolomieu The smallmouth bass favors cooler, rockier rivers and lakes than its largemouth relative, and its jumping, hard-fighting resistance on a fishing line has made it a favorite among anglers. Read the guide →

Fish LC Smallmouth Buffalo Ictiobus bubalus The smallmouth buffalo can live for over a century, one of the longest-lived freshwater fish in North America, despite being a native species often mistaken for an invasive carp. Read the guide →

Birds LC Snow Goose Anser caerulescens The snow goose gathers in flocks that can exceed a million birds, and grazing pressure from this hyperabundant population has visibly damaged the fragile Arctic tundra it breeds on. Read the guide →

Amphibians LC Southern Chorus Frog Pseudacris nigrita The southern chorus frog calls from shallow, grassy ditches and temporary ponds across the southeastern coastal plain, carrying three dark stripes down an otherwise small, unremarkable body. Read the guide →

Amphibians LC Spotted Chorus Frog Pseudacris clarkii The spotted chorus frog carries bolder, better-defined dark blotches than most of its chorus frog relatives, calling from temporary pools scattered across south-central grassland and farmland. Read the guide →

Amphibians LC Spotted Dusky Salamander Desmognathus conanti The spotted dusky salamander carries light blotches along its back, a marking more pronounced than in many of its closely related dusky salamander cousins found across the same southeastern streams. Read the guide →

Fish LC Spotted Sunfish Lepomis punctatus The spotted sunfish carries neat rows of small dark spots along its sides, favouring the quiet, vegetated waters and sluggish ditches of the southeastern coastal plain. Read the guide →

Reptiles LC Striped Crayfish Snake Regina alleni The striped crayfish snake stays almost entirely underwater in Florida marshes, timing its hunts specifically to catch crayfish just after they molt, when their new shells are still soft. Read the guide →

Fish LC Tangerine Darter Percina aurantiaca The tangerine darter is among the largest darters in North America, and a breeding male flushes a vivid orange along its lower body bright enough to be spotted from well above the water's surface. Read the guide →

Invertebrates NE Tapeworm Cestoda The tapeworm has no mouth and no gut at all, absorbing already-digested food directly through its skin while living entirely inside another animal's intestine. Read the guide →

Fish LC Tessellated Darter Etheostoma olmstedi The tessellated darter carries a mottled pattern of small dark blotches resembling tiny tiles, and it tolerates a wider range of water conditions than many of its pickier darter relatives. Read the guide →

Reptiles VU Two-Striped Garter Snake Thamnophis hammondii The two-striped garter snake has lost most of its southern California stream habitat to drought and development, depending on the same shrinking waterways as other threatened natives. Read the guide →

Amphibians LC Upland Chorus Frog Pseudacris feriarum The upland chorus frog calls with a sound like running a fingernail down the teeth of a comb, breeding in temporary ponds during the very first mild nights of early spring. Read the guide →

Amphibians VU Valdina Farms Salamander Eurycea troglodytes The Valdina Farms salamander was first described from a sinkhole altered by quarrying, and its entire known population still depends on groundwater flowing through that same disturbed cave system. Read the guide →

Fish LC Warmouth Lepomis gulosus The warmouth gets its name from an unusually large mouth for a sunfish, and it hunts other fish more aggressively than most of its panfish relatives while tolerating murky, weedy water they avoid. Read the guide →

Reptiles LC Western Ribbon Snake Thamnophis proximus The western ribbon snake stays close to water's edge without fully submerging, carrying three bold stripes down a slender body built for speed rather than for confrontation. Read the guide →

Reptiles LC Western Terrestrial Garter Snake Thamnophis elegans The western terrestrial garter snake ranges higher into the mountains than almost any other North American snake, found active at elevations where snow lingers well into summer. Read the guide →

Fish LC White Catfish Ameiurus catus The white catfish sits squarely between its larger and smaller relatives in size, with a forked tail that instantly separates it from the rounder-tailed bullheads sharing its own genus. Read the guide →

Fish LC White Sucker Catostomus commersonii The white sucker feeds by vacuuming the bottom sediment through a downturned, fleshy mouth, sorting out edible particles and expelling the rest in a steady cloud of disturbed silt. Read the guide →

Invertebrates LC Widow Skimmer Libellula luctuosa The widow skimmer carries bold black bands across the base of each wing, a pattern bold enough that a folk belief about males abandoning their mates gave the species its lasting name. Read the guide →

Birds LC Willet Tringa semipalmata The willet looks plain and unremarkable standing still, but the instant it takes flight, bold black-and-white wing stripes flash into view, transforming its appearance entirely. Read the guide →

Fish LC Yellow Bullhead Ameiurus natalis The yellow bullhead tolerates warm, weedy, oxygen-poor water that would drive off most other fish, and pale whitish chin barbels help distinguish it from its darker-barbeled catfish relatives. Read the guide →

Birds LC Yellow-Crowned Night-Heron Nyctanassa violacea The yellow-crowned night-heron specializes on crustaceans, using a heavy, blunt bill built for crushing crayfish and crab shells rather than the slender spear typical of most herons. Read the guide →

Fish LC Alewife Alosa pseudoharengus The alewife migrates from the ocean into freshwater to spawn, but landlocked Great Lakes populations sometimes wash ashore in mass die-offs after sudden temperature shifts. Read the guide →

Fish LC Banded Darter Etheostoma zonale The banded darter grazes algae directly off submerged rocks in fast-flowing riffles, an unusual feeding habit among darters that sets it apart from most of its strictly invertebrate-hunting relatives. Read the guide →

Amphibians EN Berry Cave Salamander Gyrinophilus gulolineatus The Berry Cave salamander lives entirely within a handful of Tennessee cave systems, keeping its larval gills and reduced eyes into adulthood in permanent underground darkness. Read the guide →

Amphibians VU Black-Spotted Newt Notophthalmus meridionalis The black-spotted newt often skips the terrestrial eft stage that defines its famous eastern relative, in some populations staying aquatic for essentially its entire life. Read the guide →

Fish LC Bluntnose Minnow Pimephales notatus The bluntnose minnow gets its name from a rounded snout that overhangs its small mouth, and breeding males grow a fleshy pad used to clean and guard the nest. Read the guide →

Invertebrates LC Brine Fly Ephydridae The brine fly develops inside water many times saltier than the ocean, surviving alkaline lakes lethal to nearly every other insect, its sheer numbers feeding entire flocks of migratory birds. Read the guide →

Fish LC Brook Stickleback Culaea inconstans The brook stickleback lacks the pelvic spines and armour plating of its well-known marine relative, a small, spineless freshwater fish whose males build and defend a woven nest of plant material. Read the guide →

Reptiles LC Brown Water Snake Nerodia taxispilota The brown water snake is the largest North American water snake, so frequently mistaken for the venomous cottonmouth that it carries the nickname false moccasin despite lacking any venom of its own. Read the guide →

Reptiles LC Chicken Turtle Deirochelys reticularia The chicken turtle carries a neck nearly as long as its own shell, and in parts of its range it nests in autumn rather than spring, an unusual reversal among turtles. Read the guide →

Fish LC Creek Chub Semotilus atromaculatus The creek chub builds a gravel nest mound by carrying stones one at a time in its mouth, a common minnow whose construction efforts sometimes attract other fish species to spawn on the same pile. Read the guide →

Reptiles LC Diamondback Water Snake Nerodia rhombifer The diamondback water snake carries a bold diamond-patterned back that leads many to mistake it for a venomous species, a large, harmless fish-eater often killed needlessly out of unwarranted fear. Read the guide →

Fish LC Fantail Darter Etheostoma flabellare The fantail darter's breeding males carry fleshy knobs on their dorsal fin spines, possibly mimicking eggs, and guard a nest glued upside down to the underside of a rock. Read the guide →

Fish LC Fathead Minnow Pimephales promelas The fathead minnow has become one of the most important fish in scientific research worldwide, with breeding males developing a fatty head pad and guarding eggs alone in a nest they clean for weeks. Read the guide →

Invertebrates LC Fishing Spider Dolomedes spp. The fishing spider walks on water using surface tension, dives underwater to escape danger, and detects prey by reading vibrations spreading across the surface. Read the guide →

Fish LC Golden Shiner Notemigonus crysoleucas The golden shiner schools in tight, mixed groups with other small fish, a shimmering, deep-bodied baitfish whose sheer abundance makes it one of the most heavily farmed fish in North America. Read the guide →

Reptiles LC Graham's Crayfish Snake Regina grahamii Graham's crayfish snake feeds almost exclusively on crayfish, timing its hunts around freshly molted, soft-shelled prey it can actually swallow without a struggle. Read the guide →

Fish LC Grass Carp Ctenopharyngodon idella The grass carp can eat close to its own body weight in aquatic plants each day, a hunger deliberately put to work controlling weeds in lakes and canals worldwide. Read the guide →

Fish LC Green Sunfish Lepomis cyanellus The green sunfish tolerates murky, degraded water better than most of its sunfish relatives, often becoming the dominant panfish in ponds and streams where others cannot persist. Read the guide →

Fish LC Greenside Darter Etheostoma blennioides The greenside darter grazes algae from rocks using an unusually long, flexible snout, a feeding style shared by few other North American stream fish. Read the guide →

Fish LC Johnny Darter Etheostoma nigrum The johnny darter is one of the most widespread and tolerant darters in North America, with males guarding a clutch of eggs glued upside down to the underside of a rock. Read the guide →

Fish LC Logperch Percina caprodes The logperch flips over small rocks with its snout to expose hidden prey underneath, a distinctive feeding technique that sets this darter apart from most other small freshwater fish. Read the guide →

Fish LC Orangethroat Darter Etheostoma spectabile The orangethroat darter's breeding males flash a vivid orange throat and blue-green banding, among the most vividly coloured of all North American stream fish. Read the guide →

Reptiles LC Plain-Bellied Water Snake Nerodia erythrogaster The plain-bellied water snake carries a solid, unmarked belly that separates it from its more boldly patterned relatives, a wide-ranging species found across a broad range of wetland habitats. Read the guide →

Reptiles LC Pygmy Rattlesnake Sistrurus miliarius The pygmy rattlesnake's rattle is so tiny it often buzzes more like an insect than a warning, a quiet trait shared by one of the smallest rattlesnake species in North America. Read the guide →

Fish LC Rainbow Darter Etheostoma caeruleum The rainbow darter's breeding males burst into vivid blue, orange, and red, a small, colourful stream fish that rivals many tropical species despite living entirely in cool North American creeks. Read the guide →

Fish LC Sockeye Salmon Oncorhynchus nerka The sockeye salmon turns from silver to brilliant scarlet to breed, the male growing a hooked jaw and hump. It navigates thousands of kilometres back to its birth stream, then spawns and dies. Read the guide →

Amphibians LC Southern Two-Lined Salamander Eurycea cirrigera The southern two-lined salamander occupies the warmer, lower share of a species complex across eastern North America, a common streamside amphibian easily mistaken for nearly identical relatives. Read the guide →

Birds LC African Jacana Actophilornis africanus The African jacana strides across floating lily pads on absurdly long toes, and it flips the usual bird script entirely — females hold territories over several males, who alone incubate the eggs. Read the guide →

Amphibians LC Bird-Voiced Treefrog Hyla avivoca The bird-voiced treefrog produces a whistling call so bird-like that it regularly fools observers into scanning the trees above rather than the swamp water below where the frog is actually calling. Read the guide →

Fish LC Blue Catfish Ictalurus furcatus The blue catfish has grown into one of the biggest invasive species headaches in the Chesapeake Bay, a massive predator that eats nearly anything and thrives in both fresh and brackish water. Read the guide →

Invertebrates LC Blue Crab Callinectes sapidus The blue crab swims as readily as it walks, its flattened rear legs working like a pair of paddles, powering a Chesapeake Bay fishery so central to the region it shaped an entire local food culture. Read the guide →

Fish LC Bowfin Amia calva The bowfin is the last survivor of a fish order otherwise extinct for tens of millions of years. It gulps air to live in stagnant swamps, and the male guards a swarm of thousands of young for weeks. Read the guide →

Amphibians LC Chacoan Horned Frog Ceratophrys cranwelli The Chacoan horned frog is nearly all mouth, an ambush predator that buries itself in soil with only its eyes exposed and strikes at anything that moves close enough, regardless of size. Read the guide →

Amphibians VU Chiricahua Leopard Frog Lithobates chiricahuensis The Chiricahua leopard frog survives in isolated pools scattered across southwestern sky-island mountains, a federally threatened species also facing a lethal amphibian fungus. Read the guide →

Fish LC Chum Salmon Oncorhynchus keta The chum salmon develops dramatic canine-like teeth during spawning season, earning it the nickname dog salmon, and undertakes one of the widest-ranging migrations of any Pacific salmon species. Read the guide →

Fish LC Crappie Pomoxis spp. The crappie schools in enormous numbers around submerged brush and timber, a light-sensitive panfish that feeds most actively at dawn and dusk and ranks among North America's most popular sport fish. Read the guide →

Fish LC Florida Gar Lepisosteus platyrhincus The Florida gar is found nowhere else on Earth but the Florida peninsula, an ambush predator armored in the same ancient diamond-scaled design shared across its entire long-lived family. Read the guide →

Fish LC Gizzard Shad Dorosoma cepedianum The gizzard shad filters plankton using a muscular, grinding gizzard-like stomach unusual among fish, an abundant forage species whose sheer numbers quietly support the predatory fish above it. Read the guide →

Amphibians NT Gulf Coast Waterdog Necturus beyeri The Gulf Coast waterdog never grows up in the usual sense, keeping its feathery gills and staying fully aquatic for life in the slow-moving streams of the southeastern coastal plain. Read the guide →

Amphibians NT Illinois Chorus Frog Pseudacris illinoensis The Illinois chorus frog spends most of the year buried in sandy soil, a burrowing frog whose musical, bell-like trill briefly announces its presence each spring before disappearing again. Read the guide →

Amphibians LC Italian Crested Newt Triturus carnifex The Italian crested newt grows a dramatic jagged crest along its back during the breeding season, a striking seasonal display that vanishes again once the newt returns to life on land each year. Read the guide →

Reptiles LC Keelback Rhabdophis tigrinus The keelback steals the very toxins from the toads it eats and stores them in glands on its own neck, a genuine case of a snake borrowing another animal's chemical defenses for its own protection. Read the guide →

Fish LC Lake Whitefish Coregonus clupeaformis The lake whitefish spawns in the coldest months, releasing eggs over gravel shoals just as winter ice begins to form, a historically vital Great Lakes commercial fish built around cold-water timing. Read the guide →

Reptiles LC Mangrove Monitor Varanus indicus The mangrove monitor swims confidently between islands across open saltwater, a semi-aquatic lizard equally at home diving after a fish as climbing a mangrove tree in search of eggs. Read the guide →

Fish LC Mooneye Hiodon tergisus The mooneye carries unusually large, reflective eyes suited to feeding in low light, a silvery North American fish belonging to one of the continent's few surviving primitive freshwater fish families. Read the guide →

Amphibians LC Mud Salamander Pseudotriton montanus The mud salamander wears nearly the same reddish, spotted colouring as its more toxic relative the red salamander, borrowing a warning pattern it never earned toxicologically. Read the guide →

Fish LC Nile Tilapia Oreochromis niloticus The Nile tilapia is farmed in more countries than almost any other freshwater fish, a mouth-brooding species whose females carry fertilized eggs and newly hatched young safely inside their own mouths. Read the guide →

Amphibians NT Paddle-Tail Newt Pachytriton spp. The paddle-tail newt spends nearly its entire life submerged in cold mountain streams, propelled by a flattened, paddle-shaped tail built for a lifestyle most newts never fully commit to. Read the guide →

Amphibians NT Pine Barrens Treefrog Hyla andersonii The Pine Barrens treefrog carries a lavender-grey body set off by a bold dark stripe and bright orange flashes on the thighs, one of North America's most strikingly patterned treefrogs. Read the guide →

Fish LC Pink Salmon Oncorhynchus gorbuscha The pink salmon is the smallest and most abundant Pacific salmon, running on a two-year life cycle so precise that entire river populations return in either even or odd years but almost never both. Read the guide →

Amphibians LC Plains Leopard Frog Lithobates blairi The plains leopard frog produces a short, chuckling call quite unlike its close relatives, one of several look-alike leopard frog species spread across the central United States. Read the guide →

Fish LC Pumpkinseed Lepomis gibbosus The pumpkinseed carries a bright red spot at the tip of its gill flap unlike most other sunfish, a small, vividly patterned panfish often the very first fish caught by children learning to fish. Read the guide →

Fish VU Pupfish Cyprinodon spp. The pupfish survives in isolated desert springs hot and salty enough to kill most other fish, an extremophile relative whose species can be found nowhere else but a single tiny pool. Read the guide →

Amphibians LC Red-Bellied Newt Taricha rivularis The red-bellied newt carries a vivid orange-red belly as a warning that its skin contains the same potent toxin found in some of its more famous newt relatives. Read the guide →

Amphibians VU Relict Leopard Frog Lithobates onca The relict leopard frog was believed extinct for decades before a small population was rediscovered near Lake Mead, one of the rarest amphibians in North America, clinging on in a few desert springs. Read the guide →

Reptiles LC Ribbon Snake Thamnophis sauritus The ribbon snake stays close enough to water to escape into it at the first sign of danger, a slender garter snake relative that hunts pond and marsh edges rather than open fields. Read the guide →

Fish LC Rock Bass Ambloplites rupestris The rock bass gets its alternate name "redeye" from a distinctly reddish iris, an aggressive, rocky-habitat sunfish relative that will strike lures meant for far larger predatory fish. Read the guide →

Amphibians EN Santa Cruz Long-Toed Salamander Ambystoma macrodactylum croceum The Santa Cruz long-toed salamander survives in only a handful of ponds squeezed by California coastal development, one of the most narrowly range-restricted amphibians in North America. Read the guide →

Fish NT Shad Alosa sapidissima Shad once ran up eastern American rivers in numbers so enormous that Revolutionary War soldiers reportedly survived on the spring run, a keystone fish whose migration still shapes river policy. Read the guide →

Fish LC Shovelnose Sturgeon Scaphirhynchus platorynchus The shovelnose sturgeon is the smallest sturgeon species in North America, using a flattened, shovel-shaped snout to stir up river-bottom sediment and expose the small invertebrates hidden underneath. Read the guide →

Birds NT Snail Kite Rostrhamus sociabilis The snail kite has a bill curved into an almost surgical hook, shaped by evolution around one specific task, extracting a single kind of apple snail cleanly from its shell. Read the guide →

Fish LC Spotted Bass Micropterus punctulatus The spotted bass fills the middle ground between its two more famous relatives, favouring rockier, moving water over the largemouth's weedy lakes while skipping the smallmouth's coldest streams. Read the guide →

Fish LC Spotted Gar Lepisosteus oculatus The spotted gar wears a body armored in thick, diamond-shaped scales largely unchanged for tens of millions of years, drifting motionless in weedy shallows until a fish swims too close. Read the guide →

Amphibians LC Squirrel Treefrog Hyla squirella The squirrel treefrog changes color across greens and browns depending on temperature and humidity, and earned the folk nickname rain frog for calling just before a storm arrives. Read the guide →

Birds LC Swallow-Tailed Kite Elanoides forficatus The swallow-tailed kite catches, eats, and even drinks entirely on the wing, its deeply forked tail allowing acrobatic mid-air turns that let it snatch prey without ever needing to land. Read the guide →

Fish LC Threadfin Shad Dorosoma petenense The threadfin shad dies off in mass numbers whenever water temperatures drop sharply, a cold-sensitive forage fish deliberately stocked across reservoirs nationwide despite that same fragility. Read the guide →

Invertebrates LC Whirligig Beetle Gyrinidae The whirligig beetle spins in tight, erratic circles across the water surface, and each of its eyes is split in two, one half watching above the surface and the other watching below at once. Read the guide →

Fish LC White Perch Morone americana The white perch tolerates fresh, brackish, and salty water within a single lifetime, an adaptable temperate bass relative whose name misleadingly links it to a completely different fish family. Read the guide →

Birds LC White-Throated Dipper Cinclus cinclus The white-throated dipper walks straight into fast mountain streams and along the riverbed underwater, the national bird of Norway and one of the only songbirds anywhere that swims for a living. Read the guide →

Invertebrates NE Zebra Mussel Dreissena polymorpha The zebra mussel attaches to hard surfaces using sticky threads most freshwater mussels lack, and a single lake population can filter enough water to reshape the whole ecosystem beneath it. Read the guide →

Amphibians LC Agile Frog Rana dalmatina An agile frog is a slender, long-legged brown frog of European woodland whose two-metre leap is the longest of any European frog, now down to a few protected populations on the Channel Islands. Read the guide →

Amphibians VU Amargosa Toad Anaxyrus nelsoni The Amargosa toad survives within one short stretch of desert river in Nevada, a population so confined that local ranchers and conservationists work together to keep its springs intact. Read the guide →

Invertebrates LC Amphipod Amphipoda An amphipod is a small, flattened crustacean found in nearly every aquatic and damp habitat on Earth, and the beach-dwelling kind can launch itself into the air by snapping its curled body straight. Read the guide →

Fish NE Freshwater Angelfish Pterophyllum scalare A freshwater angelfish is a tall, disc-shaped Amazon cichlid, a long-standing aquarium favourite, and despite its graceful look it is an ambush predator that pairs off and guards its eggs fiercely. Read the guide →

Amphibians EN Arroyo Toad Anaxyrus californicus The arroyo toad depends on a specific kind of California streambed, open sandy terraces that flood and reshape naturally, a habitat dams and development have made hard to find. Read the guide →

Invertebrates LC Backswimmer Notonectidae A backswimmer is a predatory water bug that rows through ponds upside down just below the surface, hunting insects, tadpoles, and small fish, and gives a burning bite if handled. Read the guide →

Amphibians LC Banded Newt Ommatotriton A banded newt is a small Middle Eastern newt whose breeding male grows a tall, smooth-edged crest and a striking blue-and-white-striped tail, unlike the jagged crest of most other crested newts. Read the guide →

Amphibians LC Banjo Frog Limnodynastes A banjo frog is a stout burrowing Australian frog whose call is a single resonant bonk like a plucked banjo string, and a full chorus of them across a wetland sounds like a band tuning up. Read the guide →

Birds NT Bar-tailed Godwit Limosa lapponica The bar-tailed godwit makes the longest non-stop flight of any bird — tracked from Alaska to New Zealand across the open Pacific in about 11 days without landing, resting, or feeding once. Read the guide →

Fish LC Barb Puntius and relatives A barb is a small, active, schooling cyprinid fish of Africa and Asia named for its mouth barbels, a community aquarium mainstay that needs a proper school to keep its fin-nipping in check. Read the guide →

Amphibians CR Barton Springs Salamander Eurycea sosorum The Barton Springs salamander exists nowhere on Earth except one spring complex in the middle of Austin, Texas, making its entire global population dependent on one urban waterway. Read the guide →

Birds LC Bee-eater Meropidae A bee-eater catches bees and wasps in mid-flight, then rubs the insect against a perch to squeeze out its venom and remove the stinger before eating it, a routine practised with remarkable precision. Read the guide →

Amphibians VU Black Toad Anaxyrus exsul The black toad exists nowhere on Earth except one isolated desert valley in California, one of the narrowest ranges of any vertebrate, its whole population tied to a handful of springs. Read the guide →

Birds LC Blackbird Turdus merula and Icteridae A blackbird is really two unrelated birds sharing one name, a European thrush that sings from rooftops and the mostly American Icteridae, glossy birds like the red-winged blackbird. Read the guide →

Reptiles EN Blanding's Turtle Emydoidea blandingii Blanding's turtle carries a bright yellow chin and throat that makes it look like it is always smiling, an appearance that belies how long-lived and slow to reproduce it actually is. Read the guide →

Reptiles LC Blood Python Python brongersmalis A blood python is a stout, short-tailed Southeast Asian constrictor named for the deep red blotches often marking its body, and it is among the heaviest snakes relative to its length. Read the guide →

Amphibians LC Blue-spotted Salamander Ambystoma laterale A blue-spotted salamander is a small, dark, blue-flecked salamander of the Great Lakes region that breeds with a relative to produce all-female hybrid lineages found in almost no other vertebrate. Read the guide →

Invertebrates LC Bryozoan Bryozoa A bryozoan colony is built from thousands of genetically identical microscopic animals, each living in its own tiny box-like chamber, working together as a single encrusting or branching structure. Read the guide →

Invertebrates LC Caddisfly Trichoptera A caddisfly larva builds a protective case from silk and whatever is around, sand, gravel, twigs, or shells, and artists exploit the trick by giving them gold and gems to build with instead. Read the guide →

Reptiles EN Chinese Crocodile Lizard Shinisaurus crocodilurus The Chinese crocodile lizard is a semi-aquatic lizard named for the raised, bony-looking scales down its tail. It hunts in cool forest streams and is the only surviving species of an ancient family. Read the guide →

Invertebrates LC Clam Shrimp Spinicaudata A clam shrimp is a small crustacean enclosed within a hinged, two-part shell that makes it look almost exactly like a tiny clam, though the two animals are not closely related at all. Read the guide →

Amphibians LC Columbia Spotted Frog Rana luteiventris A Columbia spotted frog is a widespread brown frog of the American Northwest and Rockies, tied to permanent water, more terrestrial than its coastal cousin, and hibernating underwater at springs. Read the guide →

Invertebrates LC Copepod Copepoda Copepods are tiny crustaceans so numerous in the ocean that they are often described as the most abundant multicellular animal group on Earth, forming the base of most marine food webs. Read the guide →

Amphibians NT Cope's Giant Salamander Dicamptodon copei Cope's giant salamander is the one member of its family that almost never grows up, keeping its feathery larval gills and living permanently in cold streams instead of walking onto land. Read the guide →

Birds LC Cormorant Phalacrocoracidae A cormorant is a dark, long-necked fishing bird that dives and chases fish with its feet, then perches with its wings spread to dry because its feathers are not fully waterproof. Read the guide →

Fish LC Corydoras Corydoras A corydoras is a small armoured whiskered South American catfish that shoals along the bottom, gulps air from the surface through its gut, and is one of the most popular aquarium fish. Read the guide →

Amphibians LC Crab-eating Frog Fejervarya cancrivora The crab-eating frog is one of the only amphibians on Earth able to tolerate brackish and even nearly full-strength seawater, surviving in mangrove swamps that would kill almost any other frog. Read the guide →

Amphibians LC Great Crested Newt Triturus cristatus A great crested newt is a large, warty European newt whose breeding male grows a spectacular jagged crest, and it is protected so strictly that its presence can halt building projects. Read the guide →

Birds NT Curlew Numenius A curlew is a large wading bird with a long, downward-curved bill built for probing deep into mud for worms, and its haunting, bubbling call is one of the most recognisable sounds of open wetlands. Read the guide →

Amphibians EN Darwin's Frog Rhinoderma darwinii Darwin's frog is a small, leaf-mimicking frog of Chile and Argentina, famous because the male broods the tadpoles in his vocal sac until they hop out of his mouth as froglets. Read the guide →

Reptiles LC DeKay's Brown Snake Storeria dekayi DeKay's brown snake is a tiny, completely harmless North American snake often confused by name with Australia's deadly eastern brown snake, despite the two having nothing but a name in common. Read the guide →

Fish LC Discus Symphysodon A discus is a round, disc-shaped Amazon cichlid, prized as the king of the aquarium, and unusual in that both parents feed their newly hatched young on mucus from their own skin. Read the guide →

Invertebrates LC Diving Beetle Dytiscidae A diving beetle is a streamlined, air-carrying pond predator whose larva, the water tiger, injects prey with digestive juices and sucks it dry, and both stages take tadpoles and small fish. Read the guide →

Reptiles DD Earless Monitor Lanthanotus borneensis The earless monitor is a secretive Bornean lizard so rarely seen it was once considered almost mythical among reptile researchers, and it is the sole living member of its own ancient lizard family. Read the guide →

Amphibians LC Eastern Narrow-mouthed Toad Gastrophryne carolinensis The eastern narrow-mouthed toad is a small, pointy-headed amphibian that eats mainly ants and termites, sometimes found sharing a burrow with a tarantula that appears to tolerate it on purpose. Read the guide →

Invertebrates NE Fairy Shrimp Anostraca A fairy shrimp is a delicate crustacean that swims upside down through temporary pools, filtering food with rows of beating legs, and whose eggs survive dry in the soil for decades between rains. Read the guide →

Reptiles EN False Gharial Tomistoma schlegelii The false gharial has the same long, narrow, fish-catching snout as the true gharial despite belonging to a separate crocodilian family, two unrelated lineages arriving at the same solution. Read the guide →

Reptiles LC File Snake Acrochordus A file snake is a fully aquatic snake of Asian and Australian waters with loose, baggy skin and rough file-like scales it uses to grip slippery fish, and it is nearly helpless out of the water. Read the guide →

Fish LC Four-Eyed Fish Anableps The four-eyed fish only has two eyes, but each one splits into an upper and lower half with its own focus, letting the fish watch for danger in the air and underwater at once. Read the guide →

Amphibians VU Georgia Blind Salamander Haideotriton wallacei The Georgia blind salamander lives its entire life in the total darkness of underground limestone aquifers, having lost both eyes and all body pigment, keeping its feathery external gills for life. Read the guide →

Fish LC Gourami Osphronemidae A gourami is a Southeast Asian labyrinth fish that breathes air at the surface, has thread-like pelvic feelers, and, in most species, the male builds a floating bubble nest and guards the eggs. Read the guide →

Birds LC Grebe Podicipedidae A grebe is a diving waterbird with legs set so far back it swims superbly but cannot walk, and it performs some of the most elaborate courtship dances of any bird, and eats its own feathers. Read the guide →

Amphibians VU Green and Golden Bell Frog Litoria aurea The green and golden bell frog was once one of southeastern Australia's commonest frogs before disease and habitat loss collapsed its range. Its best strongholds are now brick pits and quarry ponds. Read the guide →

Fish LC Halfbeak Hemiramphidae A halfbeak is a slender surface fish named for its lopsided jaw, in which only the lower half is drawn into a long, needle-like spike while the upper stays short, and several species give live birth. Read the guide →

Amphibians CR Harlequin Toad Atelopus Harlequin toads are a genus of roughly 100 brilliantly coloured Central and South American amphibians that has suffered one of the worst disease-driven collapses of any animal group on Earth. Read the guide →

Birds LC Harrier Circus A harrier is a slim, long-winged hawk that hunts by quartering low over open marsh and grassland, using an owl-like facial disc to hear prey hidden in the grass below. Read the guide →

Invertebrates NE Hydra Hydra A hydra is a tiny freshwater relative of jellyfish, a stalk of tentacles a few millimetres long that catches prey with stinging cells, clones itself by budding, and appears to barely age at all. Read the guide →

Reptiles LC Indigo Snake Drymarchon An indigo snake is a big, glossy blue-black non-venomous American snake. The eastern indigo is the longest native snake in the US, eats rattlesnakes, and shelters in gopher tortoise burrows. Read the guide →

Amphibians LC Italian Newt Lissotriton italicus The Italian newt is the smallest newt species in Europe, a tiny southern Italian amphibian that breeds in shallow, often temporary pools and can mature within its very first year of life. Read the guide →

Birds LC Jabiru Jabiru mycteria The jabiru is the tallest flying bird in the Americas, an enormous white stork with a bare black head and a bright red band circling its neck like a piece of jewelry. Read the guide →

Fish LC Killifish Cyprinodontiformes A killifish is a small, often brilliantly coloured fish, and the annual species lay eggs that survive complete drying in mud for months, hatching into a new generation after the adults have died. Read the guide →

Invertebrates LC Leech Hirudinea A leech is a segmented worm with a sucker at each end that can drink several times its own body weight in blood in a single meal, using an anaesthetic in its saliva so the host never feels the bite. Read the guide →

Amphibians LC Lesser Siren Siren intermedia The lesser siren is an eel-like aquatic salamander that keeps its feathery gills for life and has only tiny front legs. It survives drought by sealing itself in a mucus cocoon in the mud for months. Read the guide →

Fish LC Loach Cobitidae and Botiidae A loach is a slender, whiskered bottom-dwelling fish found across Eurasia and Southeast Asia, and one kind, the weather loach, is so sensitive to air pressure that it grows restless before a storm. Read the guide →

Amphibians LC Long-tailed Salamander Eurycea longicauda The long-tailed salamander carries a tail making up nearly two-thirds of its total body length, patterned with a distinctive herringbone marking that helps set it apart from other salamanders. Read the guide →

Amphibians CR Mallorcan Midwife Toad Alytes muletensis The Mallorcan midwife toad was known only from fossils and presumed extinct for millions of years until a living population was discovered surviving in a remote mountain gorge on Mallorca in 1980. Read the guide →

Reptiles LC Map Turtle Graptemys A map turtle is a North American river turtle with fine contour-like lines across its shell, and females grow so much larger than males, with broader heads, that the sexes eat different food. Read the guide →

Birds LC Martin Progne and Delichon A martin is a large, dark swallow-family bird, and the purple martin of North America is now so tied to human-built birdhouses that almost the entire eastern population nests in nothing else. Read the guide →

Invertebrates LC Mayfly Ephemeroptera A mayfly spends up to two years underwater as a nymph and then, as a winged adult, may live for only a matter of hours, just long enough to mate and lay eggs before it dies. Read the guide →

Fish LC Molly Poecilia A molly is a hardy livebearing fish of coastal fresh and brackish water from the southern US to South America, and one species, the Amazon molly, is an all-female fish that clones itself. Read the guide →

Fish LC Mosquitofish Gambusia A mosquitofish is a small, hardy North American livebearer released worldwide to eat mosquito larvae, which then became one of the most damaging invasive fish, called the plague minnow in Australia. Read the guide →

Reptiles LC Mud Snake Farancia abacura A mud snake is a glossy black-and-red, non-venomous water snake of the southeastern US that specialises in eating giant aquatic salamanders, and is the source of the hoop snake legend. Read the guide →

Reptiles LC Mud Turtle Kinosternon A mud turtle is a small American freshwater turtle, close kin to the musk turtle, that can close its shell almost completely with a double hinge and often walks overland between drying ponds. Read the guide →

Fish LC Mullet Mugilidae A mullet is a schooling coastal fish that grazes algae and organic mud off the bottom with a muscular gizzard-like stomach, and it is famous for leaping clear of the water for no fully agreed reason. Read the guide →

Reptiles LC Musk Turtle Sternotherus A musk turtle is a small North American freshwater turtle that walks the bottom rather than swimming, releases a foul musk when handled, and will readily bite to defend itself. Read the guide →

Fish LC Neon Tetra Paracheirodon innesi A neon tetra is an Amazon blackwater fish, one of the most popular aquarium fish, whose electric-blue stripe is structural colour it can switch off at night, and it needs a school to feel secure. Read the guide →

Reptiles LC Nile Monitor Varanus niloticus The Nile monitor is one of Africa's largest lizards, a powerful swimmer known to raid crocodile nests for eggs, and it has established a damaging invasive population in Florida. Read the guide →

Amphibians LC Ornate Chorus Frog Pseudacris ornata The ornate chorus frog packs an unusually bold pattern of dark blotches and stripes onto a body barely bigger than a coin, one of the most strikingly marked of North America's small chorus frogs. Read the guide →

Fish VU Paddlefish Polyodon spathula A paddlefish is an ancient, shark-shaped river fish with a paddle-shaped snout covered in electric sensors to detect plankton, and its Chinese relative was declared extinct in 2022. Read the guide →

Amphibians LC Painted Frog Discoglossus A painted frog is a small blotched frog of southwest Europe with a fixed disc tongue it cannot flick out, and its relative the Israel painted frog went extinct then reappeared as a living fossil. Read the guide →

Amphibians LC Parsley Frog Pelodytes A parsley frog is a small southwest-European frog flecked bright green as if dusted with chopped parsley, a good climber despite lacking toe pads, that often breeds in autumn as well as spring. Read the guide →

Fish LC Pipefish Syngnathidae A pipefish is a thin, tube-bodied relative of the seahorse that hides among seagrass and weed by mimicking it, and like the seahorse it is the male, not the female, that becomes pregnant. Read the guide →

Invertebrates LC Planarian Tricladida A planarian is a flatworm that can be cut into dozens of pieces and regrow a complete, fully functional individual from nearly every fragment, including one that regrows a working brain from scratch. Read the guide →

Fish LC Platy Xiphophorus maculatus A platy is a small, hardy, brightly coloured livebearer from Central America, one of the easiest of all aquarium fish, and a close relative of the swordtail with which it freely interbreeds. Read the guide →

Fish LC Plecostomus Hypostomus and relatives A plecostomus is a South American armoured catfish with a sucker mouth and bony plates, sold as an aquarium algae-eater, though it outgrows most tanks and, released, becomes an invasive pest. Read the guide →

Amphibians LC Pool Frog Pelophylax lessonae A pool frog is a small green water frog of Europe, and it was recognised as a genuine British native only after it went extinct there, and was then reintroduced from Sweden. Read the guide →

Amphibians CR Puerto Rican Crested Toad Peltophryne lemur The Puerto Rican crested toad is the island's only native toad, once thought extinct for decades, and it now survives largely through sustained amphibian captive breeding. Read the guide →

Amphibians NT Pyrenean Newt Calotriton asper The Pyrenean newt is a mountain amphibian so adapted to cold, fast-flowing streams that its eggs are laid individually under stones in the current rather than in a still pond. Read the guide →

Reptiles LC Queen Snake Regina septemvittata The queen snake is a North American water snake with one of the most specialised diets of any snake on Earth, feeding almost exclusively on freshly moulted crayfish too soft-shelled to fight back. Read the guide →

Reptiles LC Racer Coluber constrictor A racer is a fast, slender, alert North American snake that hunts by day with its head raised above the grass, and despite the name constrictor it usually just pins prey and swallows it alive. Read the guide →

Reptiles LC Rainbow Snake Farancia erytrogramma A rainbow snake is a large, iridescent, non-venomous American snake that specialises almost entirely in hunting eels, and it is so secretive that even where common it is rarely ever seen. Read the guide →

Fish LC Rasbora Rasbora and Trigonostigma A rasbora is a small, peaceful, schooling Southeast Asian cyprinid fish, and the harlequin rasbora, with its orange body and black triangular patch, is one of the most popular aquarium fish. Read the guide →

Amphibians LC Ringed Salamander Ambystoma annulatum The ringed salamander breaks from nearly every other mole salamander by breeding in autumn instead of spring, emerging from underground burrows just as the first cool rains of fall begin to fall. Read the guide →

Amphibians LC Rocket Frog Litoria nasuta A rocket frog is a slender, pointy-nosed Australian tree frog with enormously long hind legs that can jump about fifty times its body length, among the best jumps relative to size of any frog. Read the guide →

Invertebrates LC Rotifer Rotifera A rotifer is a microscopic animal whose crown of beating cilia looks like a spinning wheel, and some species can dry out completely for years and revive within minutes once rewetted. Read the guide →

Reptiles LC Rough Green Snake Opheodrys aestivus The rough green snake is a slender, tree-climbing serpent whose keeled scales and green colour let it move through leafy branches almost invisibly, often mistaken for a vine swaying in the breeze. Read the guide →

Amphibians LC Running Frog Kassina A running frog is an African frog that walks and runs on alternating legs instead of hopping, a gait almost unique among frogs, and it can inflate its body to control buoyancy in water. Read the guide →

Birds LC Screamer Anhimidae A screamer carries sharp bony spurs on each wing for fighting rivals, unusually dense bones instead of the typical lightweight bird skeleton, and a call loud enough to carry for miles. Read the guide →

Fish LC Sculpin Cottidae A sculpin is a big-headed, spiny, bottom-dwelling fish that relies on camouflage and stillness rather than speed, found in cold coastal waters, tide pools, and freshwater streams worldwide. Read the guide →

Amphibians LC Sheep Frog Hypopachus variolosus The sheep frog is a small burrowing amphibian named for a call that sounds remarkably like a bleating sheep, and it defends itself with a distasteful skin secretion rather than trying to flee. Read the guide →

Amphibians LC Small-Mouthed Salamander Ambystoma texanum The small-mouthed salamander gets its name from a narrow mouth built for pulling earthworms out of soil, and its genes have fuelled one of the strangest reproductive lineages among salamanders. Read the guide →

Reptiles LC Smooth Green Snake Opheodrys vernalis The smooth green snake is a gentle green snake so well camouflaged in grass it is far more often heard rustling away than seen, and it turns dull blue-grey after death as its yellow pigment fades. Read the guide →

Fish LC Snook Centropomus undecimalis The snook is a prized coastal game fish with a distinctive black lateral line running the length of its body, and it begins life as a male before some individuals later transition into females. Read the guide →

Amphibians LC Southern Leopard Frog Lithobates sphenocephalus The southern leopard frog can leap an impressive distance in a single bound, a spotted, pointed-nosed frog common across the southeastern United States that often strays well away from water. Read the guide →

Reptiles EN Spotted Turtle Clemmys guttata A spotted turtle is a small black semi-aquatic turtle of eastern North America dotted with bright yellow spots, once common in wet meadows and now Endangered from wetland loss and collection. Read the guide →

Invertebrates LC Stonefly Plecoptera A stonefly is an ancient, flat-winged aquatic insect that crawls out of the water to moult on rocks and streamside plants, and with mayflies and caddisflies it is a standard measure of clean water. Read the guide →

Amphibians LC Streamside Salamander Ambystoma barbouri The streamside salamander broke from its family's usual habit of breeding in still ponds, laying its eggs instead in flowing streams where its larvae hatch already equipped to handle a current. Read the guide →

Reptiles LC Sunbeam Snake Xenopeltis unicolor The sunbeam snake is a burrowing snake whose smooth, glossy scales scatter light into a shifting rainbow sheen, an iridescent effect on a plain brown body that gives the species its name. Read the guide →

Birds LC Swallow Hirundinidae A swallow is a slender, fork-tailed bird that catches insects on the wing over fields and water, builds a cup of mud, and makes some of the longest migrations of any small land bird. Read the guide →

Fish LC Swordtail Xiphophorus hellerii A swordtail is a hardy Central American livebearer named for the blade extending from the male's tail, a classic beginner aquarium fish and a lab model for the genetics of colour and melanoma. Read the guide →

Fish LC Tetra Characidae A tetra is one of thousands of small, schooling freshwater fish in one enormous family, ranging from the aquarium-famous neon tetra to a considerably less peaceful relative, the piranha. Read the guide →

Amphibians LC Three-toed Amphiuma Amphiuma tridactylum The three-toed amphiuma is the largest species of amphiuma, an eel-like salamander with legs so tiny they are barely functional, delivering a surprisingly painful bite despite its harmless look. Read the guide →

Invertebrates LC Tongue Worm Pentastomida A tongue worm is a parasite living inside the lungs or nasal passages of a reptile, and despite its wormlike body it is now understood to be a bizarre, highly modified relative of crustaceans. Read the guide →

Invertebrates NE Triops Triops A triops, or tadpole shrimp, is a shield-backed crustacean of temporary pools whose body plan has barely changed in 200 million years, and whose eggs survive dry in the soil for decades. Read the guide →

Fish LC Upside-Down Catfish Synodontis nigriventris The upside-down catfish spends much of its life swimming belly-up, an inverted posture that lets it graze algae and insects from the undersides of leaves and the water's surface film. Read the guide →

Birds LC Wagtail Motacilla A wagtail is a slender songbird named for its habit of constantly bobbing its long tail up and down while walking, a near-continuous motion whose exact purpose is still debated. Read the guide →

Invertebrates LC Water Boatman Corixidae A water boatman is a small oval water bug that swims right-way-up and rows with hair-fringed hind legs, feeding mostly on algae, and one tiny kind is the loudest animal on Earth for its size. Read the guide →

Invertebrates LC Water Flea Daphnia A water flea is a transparent, jerkily swimming crustacean whose beating heart is visible through its shell, and it can switch from cloning itself to sexual reproduction when its pond turns hostile. Read the guide →

Invertebrates LC Water Scorpion Nepidae A water scorpion is a predatory water bug that grabs prey with folding mantis-like front legs and breathes through a long tail-like tube, and despite the name it is not a scorpion and cannot sting. Read the guide →

Reptiles LC Water Snake Nerodia A water snake is a non-venomous North American snake of ponds and rivers, often killed because it is mistaken for a cottonmouth, though it has round pupils, no facial pits, and swims at the surface. Read the guide →

Amphibians LC Woodhouse's Toad Anaxyrus woodhousii Woodhouse's toad is a highly adaptable North American toad, tolerating everything from river floodplains to farmland, and it readily interbreeds with related toad species where ranges overlap. Read the guide →

Birds LC Wren Troglodytidae A wren is a tiny, round, brown bird with a cocked-up tail and a song astonishingly loud for its size, and the males of several species build a set of spare nests for the female to choose from. Read the guide →

Amphibians CR Achoque Ambystoma dumerilii An achoque is a Critically Endangered Mexican salamander, a gilled, aquatic cousin of the axolotl that lives in one shrinking lake and is bred by an order of nuns for a traditional cough syrup. Read the guide →

Reptiles NE Alligator Alligatoridae An alligator is a broad-snouted crocodilian of the Americas and China, and the family, which also includes the caimans, split from true crocodiles around 80 million years ago. Read the guide →

Amphibians NE Amphiuma Amphiumidae An amphiuma is an eel-like aquatic salamander of the US Southeast with four tiny useless legs, a painful bite, and a red blood cell so large it is a standard biology teaching specimen. Read the guide →

Reptiles LC Anaconda Eunectes An anaconda is a giant South American boa that hunts from the water, killing by constriction, and the green anaconda is the heaviest snake in the world, though the reticulated python grows longer. Read the guide →

Fish EN Arowana Osteoglossidae An arowana is a long freshwater fish that leaps from the water to grab insects and birds off branches, mouthbroods its young, and, as the Asian dragon fish, sells for tens of thousands of dollars. Read the guide →

Fish LC Barramundi Lates calcarifer A barramundi is a fish of Indo-Pacific rivers and estuaries that migrates between fresh and salt water, starts life as a male and later turns female, and is a prized Australian sport and food fish. Read the guide →

Reptiles LC Basilisk Lizard Basiliscus A basilisk lizard is a crested Central American lizard that escapes by sprinting across open water on its hind legs, staying up for several metres before it sinks and swims. Read the guide →

Fish NE Bass Micropterus, Morone, and others A bass is any of many unrelated spiny-finned fish that share the name, from the freshwater largemouth bass, the top sport fish in North America, to striped bass, sea bass, and the invasive Nile perch. Read the guide →

Mammals LC Beaver Castor A beaver is a large, dam-building rodent that reshapes whole river valleys, felling trees with self-sharpening orange teeth and flooding land to make the deep pond it needs to stay safe. Read the guide →

Reptiles VU Box Turtle Terrapene A box turtle is a small North American land turtle whose hinged lower shell folds like a box to seal it inside, and it may spend its whole life within a few hundred metres of where it hatched. Read the guide →

Invertebrates LC Brine Shrimp Artemia A brine shrimp is a tiny crustacean of salt lakes that filters algae from the water, lays eggs that survive years of drying, and is sold worldwide as fish food and, as sea monkeys, as a novelty pet. Read the guide →

Amphibians NE Bullfrog Lithobates, Pyxicephalus, and others A bullfrog is any of several large, loud, predatory frogs on different continents that share a booming call and an appetite for anything they can swallow, from insects to birds and snakes. Read the guide →

Reptiles LC Caiman Caimaninae A caiman is a Central and South American crocodilian, mostly smaller than a true alligator, ranging from the metre-long dwarf caiman to the black caiman, which rivals the largest crocodiles. Read the guide →

Amphibians LC California Newt Taricha torosa A California newt is a coast-range salamander whose skin holds enough tetrodotoxin to kill a person if eaten, locked in an evolutionary arms race with the garter snakes that eat it anyway. Read the guide →

Amphibians NT Cascades Frog Rana cascadae A Cascades frog is a mountain frog of the Pacific Northwest that breeds in meltwater pools at the snow line, and it has vanished from the south of its range as stocked trout and disease moved in. Read the guide →

Reptiles VU Chinese Water Dragon Physignathus cocincinus A Chinese water dragon is a green, long-tailed lizard of Southeast Asian streams that dives and swims to escape danger, has a light-sensing third eye on its head, and is a popular but demanding pet. Read the guide →

Amphibians LC Chorus Frog Pseudacris A chorus frog is a small striped North American frog whose spring call sounds like a finger run down the teeth of a stiff comb, multiplied by hundreds of males in a flooded field. Read the guide →

Fish NE Cichlid Cichlidae A cichlid is a freshwater fish of a huge, fast-evolving family famous for elaborate parental care, mouthbrooding, and explosive bursts of new species in the African Great Lakes. Read the guide →

Reptiles LC Copperhead Agkistrodon contortrix A copperhead is a coppery, hourglass-banded pit viper of the eastern United States, the cause of more venomous bites there than any other snake but rarely a danger to a healthy adult. Read the guide →

Amphibians CR Corroboree Frog Pseudophryne corroboree A corroboree frog is a tiny yellow-and-black amphibian of Australia's alpine bogs, one of the few vertebrates that makes its own poison, and now nearly wiped out by an introduced fungus. Read the guide →

Amphibians LC Cricket Frog Acris A cricket frog is a tiny North American frog named for its dry clicking call, like two pebbles tapped together, and it can leap over a metre from a 3-centimetre body. Read the guide →

Birds NE Cuckoo Cuculidae A cuckoo is a slender, long-tailed bird, famous for the species that lay eggs in other birds' nests, tricking the hosts into raising a chick that hatches early and heaves out their own young. Read the guide →

Mammals NE Dolphin Delphinidae A dolphin is a small toothed whale, one of the most intelligent animals alive, that hunts by echolocation, lives in fluid social groups, and passes hunting traditions from mother to calf. Read the guide →

Birds NE Duck Anatidae A duck is a small waterfowl with a broad flat bill, waterproof feathers kept oiled by preening, and often a bright male and a drab female, the female usually raising the ducklings alone. Read the guide →

Amphibians LC Dwarf Clawed Frog Hymenochirus A dwarf clawed frog is a thumbnail-sized, fully aquatic African frog with all four feet webbed and no tongue or teeth, that rests in a motionless spread-eagled float and is a common aquarium pet. Read the guide →

Invertebrates NE Earwig Dermaptera An earwig is a slim nocturnal insect with a pair of curved pincers at its rear, folded wings it rarely uses, and, unusually for an insect, a mother that guards and grooms her eggs and young. Read the guide →

Amphibians LC Edible Frog Pelophylax kl. esculentus The edible frog is not a true species but a hybrid of two other frogs, reproducing by discarding half its own genome each generation and borrowing a fresh copy from a parent species. Read the guide →

Amphibians LC Fire-bellied Newt Cynops A fire-bellied newt is a small, largely aquatic East Asian newt, drab above and vivid orange or red below, whose skin carries the same nerve poison as a pufferfish, and it is a popular pet. Read the guide →

Amphibians LC Fire-bellied Toad Bombina A fire-bellied toad is a small Eurasian amphibian with a drab warty back and a vivid orange-and-black belly, which it flashes by arching into a back-bend to warn a predator of the toxin in its skin. Read the guide →

Invertebrates NE Fly Diptera A fly is an insect with a single pair of wings, the second pair shrunk to tiny balancing organs; the order holds the most agile insect fliers, along with the mosquito and the housefly. Read the guide →

Amphibians NE Flying Frog Rhacophoridae A flying frog is an Asian and African tree frog that glides between trees on huge webbed feet; its family also holds the foam-nest frogs and the moss frogs that vanish against lichen. Read the guide →

Fish NE Gar Lepisosteidae A gar is a long, cylindrical, heavily armoured freshwater fish little changed in 100 million years, breathing air through its swim bladder and ambushing prey with a beak full of needle teeth. Read the guide →

Reptiles NE Garter Snake Thamnophis A garter snake is a small, striped, mild-mannered North American snake, the continent's most widespread, that survives being eaten by toxic newts and gathers by the thousand in winter dens. Read the guide →

Birds NE Goose Anserinae A goose is a large grazing waterfowl between the ducks and the swans in size, migrating in V-formations, pairing for many years, and defending its nest and goslings with real aggression. Read the guide →

Amphibians LC Gray Tree Frog Hyla versicolor A gray tree frog is a small, warty North American tree frog that shifts between grey and green, winters frozen almost solid, and hides two identical species told apart only by their trill. Read the guide →

Amphibians LC Green Toad Bufotes viridis A green toad is a green-and-white toad of Europe and Asia that tolerates heat, drought, and salt better than almost any amphibian, and whose long trill is often mistaken for a cricket or a bird. Read the guide →

Fish LC Guppy Poecilia reticulata A guppy is a live-bearing fish from northeastern South America, one of the most popular aquarium fish, a model for studying evolution in the wild, and an invasive pest far outside its home range. Read the guide →

Amphibians LC Japanese Tree Frog Dryophytes japonicus A Japanese tree frog is a small green tree frog of East Asian rice paddies whose night chorus fills the countryside, and whose call timing has been studied to design better wireless networks. Read the guide →

Birds NE Kingfisher Alcedinidae A kingfisher is a compact, big-headed, dagger-billed bird, most famous for the species that dive headfirst into water to catch fish, though many kingfishers live in dry forest and never fish at all. Read the guide →

Fish NE Lamprey Petromyzontiformes A lamprey is a jawless fish with a round rasping sucker for a mouth, one of only two surviving lines of the earliest vertebrates; its larvae spend years buried blind in river mud. Read the guide →

Amphibians LC Leopard Frog Lithobates pipiens and relatives A leopard frog is a slim green or brown North American frog scattered with dark halo-ringed spots, once so common that it was collected by the million for dissection classes and is now in decline. Read the guide →

Birds LC Loon Gavia A loon is a diving waterbird of northern lakes, a fish hunter with solid bones and legs set so far back that it can barely walk, and its wailing calls are an emblem of the wilderness. Read the guide →

Fish NE Lungfish Dipnoi A lungfish is a freshwater fish with true lungs that must breathe air to survive, and the African and South American species can seal themselves in a mud cocoon and wait out years of drought. Read the guide →

Amphibians NE Lungless Salamander Plethodontidae A lungless salamander has no lungs and breathes through its skin and mouth lining, a trade that ties it to cool damp forest but built the largest and most varied salamander family on Earth. Read the guide →

Amphibians EN Mantella Mantella A mantella is a tiny, vividly coloured frog found only in Madagascar that looks and behaves just like an unrelated South American poison frog, and most of its 16 or so species are threatened. Read the guide →

Invertebrates NE Millipede Diplopoda A millipede is a slow, rounded, many-legged animal with two pairs of legs on most body segments, feeding on dead leaves and defending itself with toxic or foul chemicals rather than a bite. Read the guide →

Amphibians VU Oregon Spotted Frog Rana pretiosa An Oregon spotted frog is the most aquatic frog of the Pacific Northwest, a marsh species that has lost about 90 percent of its range and is among the most endangered amphibians in the western US. Read the guide →

Fish LC Oscar Fish Astronotus ocellatus An oscar is a large, interactive Amazonian cichlid kept as a pet for its dog-like personality and its habit of rearranging the tank, though it grows to 30 cm and needs a very large aquarium. Read the guide →

Mammals NE Otter Lutrinae An otter is a sleek, playful member of the weasel family built for hunting in water, kept warm by dense fur rather than blubber, and the sea otter uses stone tools and holds hands while it sleeps. Read the guide →

Amphibians LC Pacific Giant Salamander Dicamptodon A Pacific giant salamander is an amphibian of cold Pacific Northwest streams, one of the few salamanders with a voice, big enough to eat mice and snakes, and often keeping its gills for life. Read the guide →

Fish LC Peacock Bass Cichla A peacock bass is a hard-striking South American cichlid, not a true bass, that is one of the top freshwater sport fish and a destructive invader where it has been introduced outside the Amazon. Read the guide →

Birds NE Pelican Pelecanidae A pelican is a huge water bird whose stretchy throat pouch holds more than its stomach, and it fishes by scooping in coordinated groups or, in the brown pelican, by plunge-diving from height. Read the guide →

Fish NE Perch Percidae A perch is a spiny-finned freshwater fish of the family Percidae, which includes the yellow and European perch, the walleye and zander, and the many tiny darters of North American streams. Read the guide →

Fish NE Pike Esocidae A pike is a long, torpedo-shaped ambush predator of cool fresh water, holding still among weeds until prey drifts close, then striking in a burst so fast it is over before the prey reacts. Read the guide →

Fish NE Piranha Serrasalmidae A piranha is a deep-bodied South American fish with interlocking triangular teeth and a bite force among the strongest for its size of any animal, and most of its fearsome reputation is myth. Read the guide →

Reptiles LC Rat Snake Pantherophis and relatives A rat snake is a non-venomous constrictor of Northern Hemisphere farmland and forest that hunts rodents and birds, climbs well, and is one of the most useful snakes to have around a barn. Read the guide →

Amphibians NE Reed Frog Hyperoliidae A reed frog is a small, often brilliantly coloured African tree frog that clings to reeds and grass stems above water, calls in loud night choruses, and in some species can change sex as an adult. Read the guide →

Birds LC Robin Turdus migratorius and Erithacus rubecula A robin is one of two unrelated red-breasted songbirds sharing the name — the large American robin, a lawn-worm hunter, and the small round European robin, a fierce Christmas-card fixture. Read the guide →

Fish CR Sawfish Pristidae A sawfish is a ray, not a shark, whose snout is drawn into a tooth-studded blade it swings sideways to stun fish and sense prey, and all five species are now Endangered or Critically Endangered. Read the guide →

Invertebrates NE Shrimp Caridea and Dendrobranchiata A shrimp is a small, slender swimming crustacean with a fan tail for flicking backward out of danger, and shrimp of some kind live in nearly every wet habitat, from the abyss to hot springs. Read the guide →

Amphibians LC Sierra Newt Taricha sierrae A Sierra newt is a stout newt of the western Sierra Nevada foothills, recently split from the California newt, whose skin holds tetrodotoxin and whose spring migrations cross roads by the thousand. Read the guide →

Amphibians NE Siren Sirenidae A siren is an eel-shaped aquatic salamander that keeps its feathery gills for life, has only tiny front legs and no hind legs at all, and can seal itself in a mud cocoon to survive a pond drying up. Read the guide →

Fish LC Snakehead Channidae A snakehead is an air-breathing predator from Asia and Africa that survives out of water and wriggles over wet ground, and a few released species have become notorious North American invaders. Read the guide →

Reptiles NE Snapping Turtle Chelydridae A snapping turtle is a large, powerful freshwater turtle with a shell too small to hide in, a long striking neck, and a bite it uses to defend itself on land, though in the water it would rather flee. Read the guide →

Reptiles EN Softshell Turtle Trionychidae A softshell turtle has a flat, leathery shell instead of a hard one and a long snorkel of a snout, and it breathes underwater through its skin and throat, staying buried in river mud for hours. Read the guide →

Fish NE Stingray Myliobatoidei A stingray is a flattened relative of the shark that ripples its fins along the sea floor, and it carries venomous barbed tail spines used only in defence, when a predator or a foot presses on it. Read the guide →

Birds NE Stork Ciconiidae A stork is a tall, heavy-billed bird that soars on broad wings, is nearly voiceless so it talks by clattering its bill, and in Europe nests for generations on village chimneys. Read the guide →

Amphibians NT Striped Newt Notophthalmus perstriatus A striped newt is a small red-striped newt of the southeastern US that breeds in seasonal ponds, shelters in gopher tortoise burrows through drought, and is one of the region's rarest amphibians. Read the guide →

Fish CR Sturgeon Acipenseridae A sturgeon is a huge, armour-plated fish little changed in 200 million years, feeling for food along the riverbed with whiskered barbels, and one of the most endangered groups of animals on Earth. Read the guide →

Fish VU Tarpon Megalops atlanticus A tarpon is a huge, armour-scaled silver gamefish of warm coasts that gulps air to survive stagnant water, leaps clear when hooked, and is among the most prized catch-and-release sport fish. Read the guide →

Invertebrates NE Tick Ixodida A tick is an eight-legged, blood-feeding arachnid that waits on vegetation for a passing animal and clings on for days, spreading more diseases to people and livestock than anything but the mosquito. Read the guide →

Fish LC Tigerfish Hydrocynus A tigerfish is a fast, striped, dagger-toothed African river predator, and the goliath tigerfish is feared as the African piranha and has been filmed leaping to catch swallows in flight. Read the guide →

Fish LC Tilapia Oreochromis and relatives A tilapia is a hardy African cichlid that has become one of the most farmed and eaten fish in the world, prized for fast growth on a plant diet and blamed as an invasive pest outside Africa. Read the guide →

Fish LC Zebrafish Danio rerio A zebrafish is a small striped aquarium minnow that has become one of biology's top laboratory animals because its see-through embryos develop outside the body and it regrows damaged organs. Read the guide →

Amphibians LC Moor Frog Rana arvalis The moor frog is an ordinary brown frog most of the year, but for a few days during the spring breeding frenzy the males turn a vivid sky blue. The colour fades within a week. Read the guide →

Birds LC Sunbittern Eurypyga helias The sunbittern is a slender, cryptically patterned wading bird that, when threatened, snaps its wings wide to reveal two huge chestnut-and-gold eyespots, becoming what looks like a much larger face. Read the guide →

Fish EN Atlantic Sturgeon Acipenser oxyrinchus The Atlantic sturgeon is an armoured, bony-plated fish whose lineage stretches back over 100 million years. Its roe once fuelled a caviar boom so intense it nearly wiped the species out. Read the guide →

Amphibians LC Yellow-bellied Toad Bombina variegata The yellow-bellied toad flips onto its back and arches into a warning pose when threatened, flashing a vivid black-and-yellow belly usually hidden from view. Read the guide →

Reptiles NT Eastern Indigo Snake Drymarchon couperi The eastern indigo snake is the longest native snake in North America, a glossy blue-black constrictor that regularly eats venomous rattlesnakes unharmed by their bites. Read the guide →

Birds LC Great White Pelican Pelecanus onocrotalus The great white pelican has one of the largest wingspans of any flying bird and a throat pouch that holds more than its stomach. Groups sometimes hunt cooperatively, herding fish together. Read the guide →

Birds LC Wood Duck Aix sponsa The wood duck is one of the most colourful waterfowl in North America, the male patterned in iridescent green, purple, and chestnut. It nests in tree cavities many metres up. Read the guide →

Reptiles LC Diamondback Terrapin Malaclemys terrapin The diamondback terrapin is the only turtle living exclusively in brackish water, patrolling salt marshes where fresh and salt water mix. Glands near its eyes let it excrete salt like a sea turtle. Read the guide →

Fish LC Longnose Gar Lepisosteus osseus The longnose gar looks almost unchanged from fish that swam alongside early dinosaurs, its narrow beak-like snout lined with needle-sharp teeth. Its scales are hard enough to have made arrowheads. Read the guide →

Birds LC Roseate Spoonbill Platalea ajaja The roseate spoonbill feeds by swinging its flat, spoon-shaped bill through shallow water, snapping shut the instant it touches food. Its pink plumage comes entirely from pigments in its prey. Read the guide →

Amphibians LC Cuban Tree Frog Osteopilus septentrionalis The Cuban tree frog is the largest tree frog in North America and a destructive invader in Florida, where it eats native frogs and lizards and clogs plumbing and electrical boxes. Read the guide →

Invertebrates NE Fire Ant Solenopsis invicta The red imported fire ant swarms in the thousands and stings in unison, each ant pivoting on its jaws to sting repeatedly. Colonies link legs into living rafts that survive floods. Read the guide →

Reptiles LC Glass Lizard Ophisaurus The glass lizard looks exactly like a snake but is a lizard that lost its legs, keeping eyelids and ear openings a snake never has. Its tail shatters into pieces when grabbed. Read the guide →

Amphibians LC Hourglass Tree Frog Dendropsophus ebraccatus The hourglass tree frog is one of the only amphibians known to switch egg-laying strategy by risk, laying eggs on land in some ponds and directly in the water in others. Read the guide →

Amphibians LC Northern Cricket Frog Acris crepitans The northern cricket frog is a thumbnail-sized frog whose call sounds like two pebbles clicked together, faster and faster. It is one of the best jumpers of any vertebrate for its size. Read the guide →

Mammals EN Proboscis Monkey Nasalis larvatus The male proboscis monkey carries a huge pendulous nose that amplifies his honking calls. It is also one of the very few primates that swims well, crossing rivers with webbed feet. Read the guide →

Amphibians LC Red Salamander Pseudotriton ruber The red salamander is a bright coral-red, black-spotted lungless salamander of eastern US springs. Its colour mimics the genuinely toxic red eft so predators leave it alone. Read the guide →

Reptiles LC Rhinoceros Viper Bitis nasicornis The rhinoceros viper is patterned in bold geometric blocks of blue, green, yellow, and black, with soft horn-like scales on its nose. It has among the longest fangs of any African snake. Read the guide →

Birds LC Scarlet Ibis Eudocimus ruber The scarlet ibis is one of the most vividly coloured birds alive, a brilliant red wader of South American mangroves. The colour comes entirely from the crabs and shrimp it eats. Read the guide →

Birds LC White Stork Ciconia ciconia The white stork is the bird behind the storks-deliver-babies myth, nesting on chimneys and rooftops across Europe and returning to the same nest for decades. One bird proved storks winter in Africa. Read the guide →

Amphibians LC African Bullfrog Pyxicephalus adspersus The African bullfrog is one of the largest frogs on Earth, a pugnacious ambush predator that eats rodents, birds, and other frogs, guards its tadpoles, and sleeps out droughts underground for years. Read the guide →

Amphibians LC African Clawed Frog Xenopus laevis The African clawed frog is a flat, tongueless, fully aquatic frog that shovels food into its mouth with its hands. It was the first pregnancy test and is now a workhorse of biology labs worldwide. Read the guide →

Fish LC African Lungfish Protopterus annectens The African lungfish breathes air with true lungs and drowns if held underwater. When its swamp dries up it burrows into the mud, wraps itself in a cocoon of mucus, and sleeps for months — or years. Read the guide →

Fish LC Alligator Gar Atractosteus spatula The alligator gar is a living fossil almost unchanged for 100 million years, the biggest fish in the Mississippi at up to 2.7 metres. It is armoured in diamond scales and can gulp air to breathe. Read the guide →

Reptiles VU Alligator Snapping Turtle Macrochelys temminckii The alligator snapping turtle is North America's largest freshwater turtle, a 100 kg ambush predator that fishes by lying still with mouth open and twitching a pink, worm-shaped lure on its tongue. Read the guide →

Amphibians LC Alpine Newt Ichthyosaura alpestris The alpine newt is a small European newt with a plain dark back and a vivid unmarked orange belly. Breeding males turn steel-blue, and some mountain populations never lose their larval gills. Read the guide →

Mammals LC American Black Bear Ursus americanus The American black bear is the most common bear in the world — a shy, adaptable forest omnivore that mostly eats plants, climbs well, and rarely attacks despite living near millions of people. Read the guide →

Amphibians LC American Bullfrog Lithobates catesbeianus The American bullfrog is the largest frog in North America, a sit-and-wait predator that eats anything it can swallow — and one of the world's most damaging invasive amphibians. Read the guide →

Reptiles VU American Crocodile Crocodylus acutus The American crocodile is a large, salt-tolerant crocodile of the Americas that is far shyer than its Old World relatives. It recovered from near-extinction in Florida to become a conservation win. Read the guide →

Amphibians LC American Green Tree Frog Dryophytes cinereus The American green tree frog is the bright green, gold-flecked frog of the US Southeast, with sticky toe pads for climbing glass and a loud, bell-like 'quonk' call that fills summer nights near water. Read the guide →

Fish VU American Paddlefish Polyodon spathula The American paddlefish swims mouth-open, straining zooplankton like a tiny whale. Its long paddle snout is covered in electroreceptors that map prey swarms. It is a toothless cousin of the sturgeon. Read the guide →

Amphibians LC American Toad Anaxyrus americanus The American toad is a warty backyard toad of eastern North America whose long trilling call rings from ponds each spring. Its glands ooze a toxin that makes dogs foam and drop it. Read the guide →

Birds LC Anhinga Anhinga anhinga The anhinga swims almost submerged, only its snaking neck showing, spears fish with a lightning bill-thrust, then perches with wings spread wide to dry its deliberately non-waterproof feathers. Read the guide →

Fish DD Arapaima Arapaima gigas The arapaima is one of the largest freshwater fish alive — up to 3 metres and 200 kg — and it must surface every 5 to 15 minutes to breathe air, gulping with a loud cough that hunters listen for. Read the guide →

Fish LC Archerfish Toxotes jaculatrix The archerfish hunts by spitting a precise jet of water to knock insects off overhanging leaves — correcting for the way light bends at the surface, and learning the skill by watching other fish. Read the guide →

Amphibians NT Argentine Horned Frog Ceratophrys ornata The Argentine horned frog is a nearly circular, all-mouth ambush predator that lunges at anything it can fit its jaws around, including prey its own size, and bites hard for a frog. Read the guide →

Reptiles LC Asian Water Monitor Varanus salvator The Asian water monitor is the second-longest lizard on Earth after the Komodo dragon — a semi-aquatic generalist that thrives in cities, canals, and mangroves across South and Southeast Asia. Read the guide →

Fish LC Atlantic Mudskipper Periophthalmus barbarus The Atlantic mudskipper is a fish that spends most of its life out of water, walking on its fins across mudflats, breathing through its skin and mouth, and defending a burrow it digs with its jaws. Read the guide →

Fish LC Atlantic Salmon Salmo salar The Atlantic salmon hatches in a river, migrates thousands of kilometres out to sea, then navigates back to its birth stream to spawn — guided by the Earth's magnetic field and by smell. Read the guide →

Fish CR Beluga Sturgeon Huso huso The beluga sturgeon is the largest fish that runs up rivers to breed — historically over 7 metres — and the source of the most expensive caviar on Earth. Wild populations have nearly vanished. Read the guide →

Fish LC Bichir Polypterus The bichir is an ancient African fish with a row of finlets down its back, thick armour scales, a pair of true lungs, and stout fins it can walk on across land between pools. Read the guide →

Reptiles LC Black Caiman Melanosuchus niger The black caiman is the Amazon's largest predator, reaching 5 metres, its dark skin aiding warmth and night camouflage. Hunted almost to extinction for its hide by the 1970s, it has recovered. Read the guide →

Invertebrates NE Bombardier Beetle Brachinus The bombardier beetle defends itself by mixing two chemicals in an internal reaction chamber and firing the boiling, caustic result out of its rear in rapid pulses, aimed with a swivelling nozzle. Read the guide →

Mammals LC Brown Rat Rattus norvegicus The brown rat is one of the most successful mammals on Earth — a smart, social, adaptable rodent that reached every continent by ship, shows empathy and ticklishness, and became the lab rat. Read the guide →

Amphibians LC Budgett's Frog Lepidobatrachus laevis Budgett's frog is a flat, wide-mouthed aquatic frog of the South American Chaco that screams and lunges with its mouth gaping when threatened, and has two fangs on its lower jaw. Read the guide →

Fish VU Bull Shark Carcharhinus leucas The bull shark is the shark that swims up rivers — hundreds or thousands of kilometres into fresh water. Learn how it survives there, why it's rated among the most dangerous sharks, and its status. Read the guide →

Reptiles LC Caiman Lizard Dracaena guianensis The caiman lizard is a large semi-aquatic South American lizard that eats almost nothing but snails, crushing the shells with broad molar-like back teeth and spitting out the fragments. Read the guide →

Birds LC Canada Goose Branta canadensis The Canada goose migrates in noisy V-formations, but many populations no longer migrate at all — they have settled year-round on lawns, golf courses, and city parks across North America and Europe. Read the guide →

Fish NE Candiru Vandellia cirrhosa The candiru is a tiny, translucent Amazonian catfish that darts into the gills of larger fish, hooks in with backward spines, and drinks blood. Its reputation for entering humans is mostly a myth. Read the guide →

Amphibians LC Cane Toad Rhinella marina The cane toad was released in Australia in 1935 to eat beetles and became one of the worst invasive species in the world. Learn why it is toxic, how far it has spread, and what is being done. Read the guide →

Mammals LC Capybara Hydrochoerus hydrochaeris The capybara is the world's largest rodent — a 50-kilogram, semi-aquatic grazer famous for its calm tolerance of almost every other animal. Learn how it lives in the wetlands of South America. Read the guide →

Reptiles CR Chinese Alligator Alligator sinensis The Chinese alligator is one of the smallest and rarest crocodilians — a 1.5-metre, burrow-digging, cold-tolerant alligator down to perhaps 150 wild adults in a few ponds in eastern China. Read the guide →

Amphibians NT Chinese Fire-belly Newt Cynops orientalis The Chinese fire-belly newt is a small black newt with an orange-blotched belly it flashes as a warning. Its skin holds tetrodotoxin, and it is one of the most heavily traded amphibians in the world. Read the guide →

Amphibians CR Chinese Giant Salamander Andrias davidianus The Chinese giant salamander is the largest amphibian on Earth, reaching 1.8 m, and a survivor of a lineage 170 million years old. Farming and hunting have all but wiped it from the wild. Read the guide →

Amphibians LC Coastal Giant Salamander Dicamptodon tenebrosus The coastal giant salamander is North America's largest land salamander, a heavy-bodied predator of Pacific streams that eats mice and snakes — and is one of the few salamanders that can bark. Read the guide →

Birds LC Common Cuckoo Cuculus canorus The common cuckoo lays its eggs in other birds' nests and leaves. The chick hatches first, heaves out the host's eggs, and is raised by foster parents a fraction of its size. Read the guide →

Amphibians LC Common Frog Rana temporaria The common frog is the familiar frog of European gardens and ponds — it can breathe through its skin, survive winter on the bottom of a pond, and returns each year to the pond it hatched in. Read the guide →

Reptiles LC Common Garter Snake Thamnophis sirtalis The common garter snake is North America's most widespread snake — a small, striped, mildly venomous hunter that survives Canadian winters by denning in the thousands and can eat toxic newts. Read the guide →

Birds LC Common Kingfisher Alcedo atthis The common kingfisher is a jewel-bright riverbank bird that dives head-first into water to spear fish. Read the guide →

Birds LC Common Loon Gavia immer The common loon is a heavy-boned diving bird that plunges 60 metres to chase fish, is nearly helpless on land, and fills quiet lakes with a wailing, yodelling call that carries for kilometres. Read the guide →

Reptiles LC Common Snapping Turtle Chelydra serpentina The common snapping turtle is a heavy, long-necked freshwater turtle that is calm underwater but bites hard on land, where its small shell leaves it no way to hide. It can live past 45 years. Read the guide →

Amphibians LC Common Toad Bufo bufo The common toad is Europe's familiar warty amphibian — a slow, poison-glanded night hunter that returns to its birth pond every spring along the same route, even when a road now runs across it. Read the guide →

Amphibians EN Darwin's Frog Rhinoderma darwinii Darwin's frog is a leaf-mimicking Chilean frog in which the father swallows his own developing eggs and carries the tadpoles in his vocal sac until they hop out as froglets. Read the guide →

Invertebrates LC Diving Bell Spider Argyroneta aquatica The diving bell spider is the only spider that lives its whole life underwater. It spins a dome of silk among pondweed, fills it with air carried down on its body, and lives inside this diving bell. Read the guide →

Invertebrates NE Dobsonfly Corydalinae The male dobsonfly has jaws half the length of its body that are too unwieldy to bite with and are used only to grapple rival males. Its aquatic larva, the hellgrammite, is prized fishing bait. Read the guide →

Reptiles VU Dwarf Crocodile Osteolaemus tetraspis The dwarf crocodile is the smallest crocodilian, rarely over 1.5 m, and one of the most armoured, with bony plates even on its eyelids. Some populations live and breed inside flooded caves. Read the guide →

Amphibians LC Eastern Newt Notophthalmus viridescens The eastern newt of North America has a three-stage life — aquatic larva, land-dwelling orange "red eft," then aquatic adult — and its skin carries a nerve toxin that keeps predators away. Read the guide →

Fish LC Electric Catfish Malapteruridae The electric catfish can deliver a shock of over 350 volts from an electric organ wrapped like a jacket around its whole body. Ancient Egyptians carved it on tomb walls 5,000 years ago. Read the guide →

Fish LC Electric Eel Electrophorus electricus The electric eel is not an eel but a knifefish that generates up to 860 volts — the strongest electric discharge of any animal. Learn how it stuns prey, breathes air, and leaps to shock threats. Read the guide →

Fish CR European Eel Anguilla anguilla The European eel is born in the Sargasso Sea, drifts to Europe as a glass eel, spends decades in rivers, then swims 5,000 km back to spawn once and die. It is now Critically Endangered. Read the guide →

Amphibians LC European Fire-bellied Toad Bombina bombina When threatened, the European fire-bellied toad arches its back and turns up its feet to flash the vivid orange-and-black warning on its belly, a posture called the unken reflex. Read the guide →

Reptiles LC Fer-de-lance Bothrops asper The fer-de-lance causes most serious snakebites in Central America — a large, fast-striking pit viper that thrives on farmland, hunts by heat, and delivers a big dose of tissue-destroying venom. Read the guide →

Invertebrates NE Fiddler Crab Uca (and related genera) Male fiddler crabs have one claw so enlarged it can be a third of their body weight, waved in set patterns to court females and warn rivals. They sift mud for microbes and regrow a lost claw. Read the guide →

Invertebrates LC Firefly Photinus pyralis The firefly is a beetle that makes near-100%-efficient cold light in its abdomen to send coded flash signals for a mate. Some females mimic other species' codes to lure and eat the males that answer. Read the guide →

Birds LC Flamingo Phoenicopterus roseus The flamingo is a filter-feeding wading bird that eats with its head upside down, gets its pink colour entirely from its food, and breeds in colonies tens of thousands strong on caustic salt lakes. Read the guide →

Amphibians EX Gastric-brooding Frog Rheobatrachus silus The gastric-brooding frog swallowed its own eggs, shut down its stomach, and grew its young inside it — then brought up fully formed froglets. Both species vanished within a decade of discovery. Read the guide →

Reptiles CR Gharial Gavialis gangeticus The gharial is a Critically Endangered Indian river crocodilian with a long thin snout built only for catching fish. Fewer than 1,000 breeding adults remain in a handful of rivers. Read the guide →

Mammals VU Giant Anteater Myrmecophaga tridactyla The giant anteater has no teeth, a 60-centimetre tongue that flicks 150 times a minute, and a body temperature lower than almost any other mammal. It eats up to 30,000 ants and termites a day. Read the guide →

Fish EN Giant Freshwater Stingray Urogymnus polylepis The giant freshwater stingray is one of the largest freshwater fish on Earth, its disc up to 2.2 m across. A 300 kg ray caught in the Mekong in 2022 set a world record. Its tail spine can pierce bone. Read the guide →

Mammals EN Giant Otter Pteronura brasiliensis The giant otter is the longest member of the weasel family — up to 1.8 m — and the most social otter, living in loud, tight family groups that hunt fish together and mob caimans off their turf. Read the guide →

Invertebrates NE Giant Water Bug Lethocerus The giant water bug is a hand-sized aquatic insect that ambushes fish, frogs, and even snakes, injecting a digestive venom and drinking them dry. Its bite is among the most painful of any insect. Read the guide →

Invertebrates NE New Zealand Glowworm Arachnocampa luminosa The New Zealand glowworm is the larva of a fungus gnat that lights up cave roofs with a blue-green glow, then catches midges on dangling lines of sticky silk beads, like a bioluminescent spider. Read the guide →

Amphibians CR Golden Mantella Mantella aurantiaca The golden mantella is a brilliant orange Madagascan frog the size of a coin, toxic from the ants it eats, that breeds only in a handful of swampy forest ponds and is now Critically Endangered. Read the guide →

Fish LC Goldfish Carassius auratus The goldfish is a domesticated Asian carp bred for colour for over a thousand years. Freed into the wild it loses its colour, grows to 2 kg, and becomes a destructive invasive fish. Read the guide →

Fish LC Goliath Tigerfish Hydrocynus goliath The goliath tigerfish is the Congo's largest predator, up to 1.5 m and 50 kg, with 32 dagger teeth that interlock when the jaws shut. It is one of very few freshwater fish reported to bite people. Read the guide →

Birds LC Great Blue Heron Ardea herodias The great blue heron is North America's largest heron, an ambush hunter that stands motionless in the shallows for minutes, then spears a fish with a lightning strike of its dagger bill. Read the guide →

Amphibians LC Great Crested Newt Triturus cristatus The great crested newt is Europe's largest newt — a black, warty amphibian with an orange belly whose breeding males grow a jagged dragon-like crest. It is strictly protected across the EU and UK. Read the guide →

Amphibians LC Greater Siren Siren lacertina The greater siren is an eel-shaped aquatic salamander with feathery gills, tiny front legs, and no hind legs at all. It keeps larval features for life and can wait out drought in dried mud for years. Read the guide →

Reptiles LC Green Basilisk Basiliscus plumifrons The green basilisk can sprint across the surface of a pond on its hind legs before it sinks — the trick that earned it the nickname "Jesus Christ lizard." Read the guide →

Invertebrates LC Common Green Darner Anax junius The common green darner is one of the fastest, most acrobatic insects and a true migrant — successive generations relay-migrate across North America each year, like monarch butterflies. Read the guide →

Reptiles LC Green Iguana Iguana iguana The green iguana is a large tree-dwelling lizard of the American tropics — a leaf-eating reptile with a third eye on its head that has become a damaging invasive species in Florida. Read the guide →

Birds EN Grey Crowned Crane Balearica regulorum The grey crowned crane wears a golden halo of bristle feathers and is one of only two cranes that can roost in trees. It is Uganda's national bird and has fallen about 80% since the 1980s. Read the guide →

Amphibians LC Hairy Frog Trichobatrachus robustus The hairy frog breaks its own toe bones and pushes them through its skin as claws when attacked. Breeding males grow hair-like skin strands that work as extra gills while guarding eggs underwater. Read the guide →

Birds LC Hamerkop Scopus umbretta The hamerkop builds the biggest nest of any bird for its size, a domed fortress of thousands of sticks over a metre across and strong enough to hold a person. A pair builds several a year. Read the guide →

Amphibians NT Hellbender Cryptobranchus alleganiensis The hellbender is North America's largest salamander, a flat, wrinkled river-dweller up to 70 cm long that breathes through its skin and needs some of the cleanest water on the continent. Read the guide →

Birds LC Hoatzin Opisthocomus hoazin The hoatzin is a strange Amazonian bird that digests leaves in a cow-like foregut, smells of manure, and whose chicks have working claws on their wings for climbing. Read the guide →

Amphibians NT Iberian Ribbed Newt Pleurodeles waltl Threatened, the Iberian ribbed newt pushes its sharp rib tips out through poison glands in its own skin, turning its flanks into a bank of venom-tipped spines. It has flown on the ISS. Read the guide →

Reptiles LC Indian Cobra Naja naja The Indian cobra is one of the "big four" snakes behind most of India's snakebite deaths. It spreads a spectacle-marked hood, and it is the snake of charmers' baskets and Hindu myth. Read the guide →

Amphibians NT Japanese Fire-belly Newt Cynops pyrrhogaster The Japanese fire-belly newt carries tetrodotoxin, the same lethal poison as a pufferfish, and flashes its scarlet belly as a warning. It can regenerate a leg, an eye lens, or heart tissue repeatedly. Read the guide →

Amphibians VU Japanese Giant Salamander Andrias japonicus The Japanese giant salamander is the world's second-largest amphibian — up to 1.5 m of wrinkled, slime-covered skin — living for decades in cold mountain streams and breathing through its body. Read the guide →

Fish CR Largetooth Sawfish Pristis pristis The largetooth sawfish is a ray with a chainsaw for a nose — a toothed blade it swings sideways to stun fish and sense their heartbeats. Once in 90 countries, it is now Critically Endangered. Read the guide →

Mammals VU Lowland Tapir Tapirus terrestris The lowland tapir is South America's largest land mammal — a browser with a short prehensile trunk and an ancient lineage barely changed in 20 million years, and the rainforest's chief seed-planter. Read the guide →

Birds LC Mallard Anas platyrhynchos The mallard is the most widespread duck on Earth and the ancestor of nearly every domestic breed. It dabbles for food, sleeps with half its brain awake, and hybridises freely. Read the guide →

Mammals NT Maned Wolf Chrysocyon brachyurus The maned wolf is not a wolf or a fox but the tallest wild canid — a long-legged, red-coated animal of South American grassland whose diet is half fruit. Read the guide →

Birds LC Marabou Stork Leptoptilos crumenifer The marabou stork is a bald, hunched African scavenger with a wingspan near 3 metres. It follows vultures to carcasses, patrols rubbish dumps, and cools itself by defecating on its own legs. Read the guide →

Amphibians LC Marbled Salamander Ambystoma opacum The marbled salamander breeds on dry land in autumn, and the female curls around her eggs in a dry pool basin and guards them for weeks until the rains arrive and flood the nest. Read the guide →

Reptiles LC Matamata Turtle Chelus fimbriata The matamata is a South American river turtle disguised as a heap of dead leaves. It never chews — it strikes its huge mouth open and vacuums a fish in whole in about 0.02 seconds. Read the guide →

Mammals LC Moose Alces alces The moose is the largest deer on Earth, tall enough to wade chest-deep and dive for water plants. Learn about its two-metre antlers and why warming winters are killing it with ticks. Read the guide →

Amphibians LC Mudpuppy Necturus maculosus The mudpuppy is a large salamander that never leaves the water or loses its feathery red external gills. It stays active under ice all winter and can live 20 years or more in a single river. Read the guide →

Birds LC Mute Swan Cygnus olor The mute swan is the classic white swan of parks and rivers — one of the heaviest flying birds and a lifelong pair-bonder, with a fierce nest defence. Where introduced it wrecks wetlands. Read the guide →

Amphibians LC Natterjack Toad Epidalea calamita The natterjack toad runs instead of hopping and has the loudest call of any amphibian in Europe, heard two kilometres off. It breeds in shallow pools, racing to transform before they dry out. Read the guide →

Reptiles LC Nile Crocodile Crocodylus niloticus The Nile crocodile is Africa's largest predator and, by number of human deaths, one of the most dangerous animals on the continent — and yet an unusually attentive reptile parent. Read the guide →

Mammals LC Nine-banded Armadillo Dasypus novemcinctus The nine-banded armadillo always has identical quadruplets, can hold its breath to walk across river bottoms, jumps straight up when startled, and is one of the few animals that carries leprosy. Read the guide →

Mammals LC North American Beaver Castor canadensis The North American beaver is the continent's largest rodent and its most powerful ecosystem engineer, felling trees and damming streams to build the ponds it lives in. Learn how it works. Read the guide →

Amphibians LC Northern Leopard Frog Lithobates pipiens The northern leopard frog was once the most common frog across much of North America and the standard classroom dissection specimen, but it has vanished from large parts of its western range. Read the guide →

Fish LC Northern Snakehead Channa argus The northern snakehead breathes air, wriggles overland between ponds, and guards its young. Introduced to the US, it is a headline invasive fish officials ask anglers to kill on sight. Read the guide →

Amphibians VU Olm Proteus anguinus The olm is a blind, cave-dwelling European salamander with pale pink skin, external gills kept for life, and the ability to survive a decade without food. It may live past 100. Read the guide →

Amphibians LC Oriental Fire-bellied Toad Bombina orientalis The Oriental fire-bellied toad is a small green frog with a vivid red-and-black belly it flashes when threatened, arching into a pose called the unken reflex to advertise its toxic skin. Read the guide →

Birds LC Osprey Pandion haliaetus The osprey is a fish-hunting raptor on every continent but Antarctica. It dives feet-first into the water, closes a valve in its nostrils, and carries fish head-first with reversible outer toes. Read the guide →

Amphibians LC Pacific Chorus Frog Pseudacris regilla The 'ribbit' heard in nearly every Hollywood night scene is the Pacific chorus frog, recorded for decades in the hills above Los Angeles. Almost no other frog on Earth actually says 'ribbit'. Read the guide →

Fish LC Pacu Piaractus brachypomus The pacu is a large Amazonian relative of the piranha with flat teeth uncannily like human molars. It cracks nuts and seeds fallen into flooded forest and scatters them like an underwater fruit bat. Read the guide →

Reptiles LC Painted Turtle Chrysemys picta The painted turtle is the most widespread native turtle in North America, a small basker with red-and-yellow trim whose hatchlings can survive being frozen almost solid through their first winter. Read the guide →

Birds LC Pileated Woodpecker Dryocopus pileatus The pileated woodpecker is a crow-sized red-crested bird that hammers rectangular holes deep into dead trees to reach carpenter ants, and its abandoned cavities house dozens of other forest species. Read the guide →

Mammals NT Platypus Ornithorhynchus anatinus The platypus is a venomous, egg-laying mammal that hunts with its eyes shut, sensing prey by electric field. Learn how this Australian oddity works and why it is now Near Threatened. Read the guide →

Amphibians EN Purple Frog Nasikabatrachus sahyadrensis The purple frog spends all but two weeks of the year buried underground, surfacing only in the monsoon to breed. Its lineage split from all other frogs around 120 million years ago. Read the guide →

Mammals LC Pygmy Marmoset Cebuella pygmaea The pygmy marmoset is the smallest monkey in the world — an adult fits in a human palm — and it lives by gnawing hundreds of holes in tree trunks and lapping the sap that seeps out. Read the guide →

Mammals LC Raccoon Procyon lotor The raccoon is a masked, ring-tailed omnivore with hands sensitive enough to identify food by touch alone. It has thrived alongside people and spread from North America across Europe and Japan. Read the guide →

Reptiles LC Red-eared Slider Trachemys scripta elegans The red-eared slider is the world's most popular pet turtle and one of its most invasive reptiles — released former pets now breed on every continent but Antarctica, outcompeting native turtles. Read the guide →

Fish LC Red-Bellied Piranha Pygocentrus nattereri The red-bellied piranha is a South American river fish with interlocking razor teeth and a fearsome reputation that outruns the facts. It shoals for safety, scavenges widely, and rarely bites people. Read the guide →

Amphibians LC Rough-skinned Newt Taricha granulosa The rough-skinned newt carries enough tetrodotoxin in its skin to kill several adults, and one person died after swallowing one on a dare. Only one predator, a local garter snake, can eat it. Read the guide →

Amphibians LC Rubber Eel Typhlonectes natans The rubber eel is not an eel but a limbless aquatic amphibian, a caecilian. It is nearly blind, and the female's young feed inside her by scraping a nutrient-rich lining off her oviduct. Read the guide →

Birds LC Sandhill Crane Antigone canadensis Sandhill cranes stage by the hundreds of thousands on Nebraska's Platte River each spring. They dance year-round, mate for life, and bugle through a windpipe coiled like a trombone. Read the guide →

Birds LC Scarlet Macaw Ara macao The scarlet macaw is a metre-long red, yellow, and blue parrot of Central and South American rainforests. Pairs mate for life, fly to clay licks to eat mineral-rich earth, and can live 50 years. Read the guide →

Fish LC Sea Lamprey Petromyzon marinus The sea lamprey is a jawless fish older than the dinosaurs. In place of jaws it has a round sucker disc lined with rings of horny teeth and a rasping tongue it uses to bore into a living fish. Read the guide →

Mammals LC Serval Leptailurus serval The serval is a slender African wild cat with the longest legs and largest ears relative to body size of any feline. Read the guide →

Birds VU Shoebill Balaeniceps rex The shoebill is a towering grey swamp bird with a huge clog-shaped bill that it uses to catch lungfish and baby crocodiles. It stands motionless for hours, then strikes in a full-body lunge. Read the guide →

Fish VU Siamese Fighting Fish Betta splendens The Siamese fighting fish breathes air from the surface, builds nests of bubbles, and flares into a blaze of fins at any rival. Wild bettas are a threatened brown fish from Thai floodplains. Read the guide →

Fish LC Silver Arowana Osteoglossum bicirrhosum The silver arowana hunts at the surface of Amazon backwaters and leaps over a metre out of the water to snatch insects, birds and bats from branches. The male broods dozens of eggs inside his mouth. Read the guide →

Amphibians CR Southern Corroboree Frog Pseudophryne corroboree The southern corroboree frog is a striking yellow-and-black Australian alpine frog that makes its own poison. Fewer than 50 survive in the wild, held from extinction only by captive colonies. Read the guide →

Reptiles LC Spectacled Caiman Caiman crocodilus The spectacled caiman is the most abundant and adaptable crocodilian in the world, named for a bony ridge between its eyes like a pair of glasses. Escaped pets have established it in southern Florida. Read the guide →

Reptiles LC Spiny Softshell Turtle Apalone spinifera The spiny softshell turtle has a flat, leathery, pancake-like shell with no hard scutes and a long snorkel snout. It breathes underwater through its skin and throat and buries itself in river sand. Read the guide →

Amphibians LC Spotted Salamander Ambystoma maculatum The spotted salamander lives underground most of the year, emerges on a few rainy spring nights to breed in vernal pools, and hosts algae inside its own cells — unique among vertebrates. Read the guide →

Amphibians LC Spring Peeper Pseudacris crucifer The spring peeper is a thumbnail-sized tree frog whose shrill mating chorus is the classic sound of early spring across eastern North America. It survives winter with much of its body frozen solid. Read the guide →

Mammals LC Star-Nosed Mole Condylura cristata The star-nosed mole has 22 pink fleshy tentacles ringing its snout — the most sensitive touch organ known — and identifies and eats prey in about a fifth of a second, faster than any other mammal. Read the guide →

Amphibians LC Surinam Toad Pipa pipa The Surinam toad is a flat, leaf-shaped aquatic frog whose babies erupt from pits in the mother's back. It has no tongue or teeth and feels for prey with star-tipped fingers in murky water. Read the guide →

Invertebrates NE Tardigrade Ramazzottius varieornatus The tardigrade, or water bear, is a half-millimetre eight-legged animal that survives boiling, freezing, vacuum, radiation, and years without water by drying into a near-lifeless tun and waiting. Read the guide →

Reptiles LC Tentacled Snake Erpeton tentaculatum The tentacled snake is a fully aquatic Southeast Asian snake with two feelers on its snout that sense nearby fish. It hunts by twitching its body to make a fish flee straight into its jaws. Read the guide →

Amphibians VU Texas Blind Salamander Eurycea rathbuni The Texas blind salamander lives its whole life in flooded limestone caves under one Texas city, with no eyes, no pigment, and blood-red external gills. It exists nowhere else on Earth. Read the guide →

Amphibians LC Tiger Salamander Ambystoma tigrinum The tiger salamander is one of the largest land salamanders in the world — a burrowing predator that spends most of its life underground and can, in some populations, skip metamorphosis for life. Read the guide →

Amphibians CR Titicaca Water Frog Telmatobius culeus The Titicaca water frog lives its whole life underwater in a high Andean lake, breathing through baggy folds of skin. It is Critically Endangered, hit by pollution and a demand for frog "juice". Read the guide →

Amphibians LC Tomato Frog Dyscophus antongilii The tomato frog is a round, bright-red Madagascan frog that puffs up like a balloon when threatened and oozes a sticky white glue from its skin that gums up a predator's mouth. Read the guide →

Amphibians LC Túngara Frog Engystomops pustulosus The tungara frog is a small Central American frog whose males add 'chuck' notes to their whine to woo females — but the same notes summon frog-eating bats. Pairs whip mucus into floating foam nests. Read the guide →

Amphibians LC Two-toed Amphiuma Amphiuma means The two-toed amphiuma is a metre-long aquatic salamander that looks like an eel and has four legs so tiny they are easy to miss. It has one of the biggest genomes of any animal, and it bites hard. Read the guide →

Amphibians LC Vietnamese Mossy Frog Theloderma corticale The Vietnamese mossy frog is covered in green-and-black bumps, ridges, and spines that make it look exactly like a clump of moss on wet rock. Startled, it tucks in its limbs and plays dead as a ball. Read the guide →

Fish LC Wels Catfish Silurus glanis The wels catfish is Europe's largest freshwater fish — a 2-to-3-metre, whiskered ambush predator that hunts by smell and electric sense in the dark, and in France it hunts pigeons on land. Read the guide →

Mammals VU West Indian Manatee Trichechus manatus The West Indian manatee is a slow, gentle aquatic herbivore that eats a tenth of its body weight in plants a day and gathers at warm-water springs to survive the winter. Read the guide →

Amphibians LC White's Tree Frog Litoria caerulea White's tree frog is a plump, placid blue-green frog with a permanent grin. Its skin secretes peptides being studied against bacteria, high blood pressure, and even HIV. Read the guide →

Mammals LC Wild Boar Sus scrofa The wild boar is the ancestor of the domestic pig, one of the most widespread mammals on Earth, and — as feral hogs — one of the most destructive invasive animals. Learn how it lives and spreads. Read the guide →

Amphibians LC Wood Frog Lithobates sylvaticus The wood frog survives being frozen solid every winter — heart stopped, most of its body water ice — then thaws back to life in spring. It ranges farther north than any other American frog. Read the guide →

Reptiles LC American Alligator Alligator mississippiensis The American alligator is a freshwater ambush predator and an ecosystem engineer whose "gator holes" keep wetlands alive. Learn how it survives freezing water and how it came back from the brink. Read the guide →

Amphibians CR Axolotl Ambystoma mexicanum The axolotl is a salamander that never grows up — it keeps its gills and stays underwater for life, and it can regrow lost limbs. Learn why it's beloved in labs and nearly extinct in the wild. Read the guide →

Birds LC Bald Eagle Haliaeetus leucocephalus The bald eagle is a fish-hunting sea eagle and a rare conservation success — back from near-extinction in the US. Learn about its huge nests, its eyesight, and why it isn't actually bald. Read the guide →

Reptiles LC Green Anaconda Eunectes murinus The green anaconda is the heaviest snake in the world, a non-venomous constrictor that ambushes prey from the water. Learn how it kills, why females dwarf males, and how it gives birth. Read the guide →

Mammals VU Hippopotamus Hippopotamus amphibius The hippopotamus spends its days in water and its nights grazing on land, sweats a red antibiotic sunscreen, and is one of Africa's most dangerous animals. Learn how this river giant lives. Read the guide →

Mammals NT Jaguar Panthera onca The jaguar is the biggest cat in the Americas and has the strongest bite of any big cat for its size — it kills by piercing the skull. Learn how it hunts in water and why it's Near Threatened. Read the guide →

Reptiles VU King Cobra Ophiophagus hannah The king cobra is the world's longest venomous snake and the only one that builds a nest for its eggs. Learn how it hunts other snakes, why it rears up, and what its venom does. Read the guide →

Reptiles LC Reticulated Python Malayopython reticulatus The reticulated python is the longest snake in the world, a non-venomous constrictor that swims between islands and lives alongside people across Southeast Asia. Learn how it hunts and breeds. Read the guide →

Reptiles LC Saltwater Crocodile Crocodylus porosus The saltwater crocodile is the largest living reptile and has the strongest bite ever measured. Learn how it ambushes prey, crosses open ocean, and how it recovered from near-extinction. Read the guide →

Mammals EN Tiger Panthera tigris The tiger is the largest cat on Earth and a solitary ambush hunter. Learn how it stalks prey, why every tiger's stripes are unique, and why fewer than 5,600 remain wild. Read the guide →