Amphibians

Darwin's Frog

Rhinoderma darwinii · also called Darwin's frog, Darwin frog

Endangered ↓ carnivoreinsectivore Temperate forest Rivers & wetlands

Darwin’s frog looks like a dead leaf with legs, right down to the pointed snout, and when a predator comes near it flips over and drifts off downstream playing the part. It was collected by Charles Darwin himself in the forests of Chile, and it does something no other frog does: the father swallows his own tadpoles and raises them inside his voice box until they climb out of his mouth as froglets.

Overview

Darwin’s frog, Rhinoderma darwinii, is a small (2.5–3.5 cm) frog of the cool, mossy floor of native southern beech and Valdivian rainforest in southern Chile and adjacent Argentina, beside slow clear streams and bogs. It hunts insects, spiders, and other small invertebrates, usually while sitting still, camouflaged as leaf litter.

Brooding in the vocal sac

The male guards the eggs for three to four weeks, then takes the moving embryos into his mouth and down into his vocal sac, where the tadpoles complete their entire development — fed by yolk and by the sac lining — before he releases the finished froglets from his mouth. It is the only frog known to do this; the extinct Australian gastric-brooding frogs used the stomach instead.

A vanishing frog

There are two species. The northern (Chile) Darwin’s frog has not been reliably seen since the 1980s and is feared extinct, a loss tied to the amphibian chytrid fungus. The southern species survives in fragments of old forest.

Status

Endangered and declining. Its native forest has been widely replaced by pine and eucalyptus plantations, and chytrid is present across the region. Conservation relies on protected reserves and captive-breeding programmes in Chile and overseas.

Darwin's Frog: common questions

How does the male Darwin's frog carry its young?

After the female lays a small clutch of eggs on damp ground, the male stays and guards them for three to four weeks. When he sees the embryos twitching inside the eggs, he picks them up with his mouth and lets them slip through openings into his vocal sac, the stretchy throat pouch normally used for calling. There the tadpoles grow, cushioned in fluid and taking nourishment from their yolk and from the sac lining, until they complete metamorphosis. Then the male opens his mouth and the tiny froglets climb or hop out, fully independent. He may carry a dozen or more at once, his throat visibly bulging.

Is Darwin's frog the only frog that broods young in its vocal sac?

Mouth and vocal-sac brooding is extremely rare. Darwin's frogs are the only frogs known to raise young all the way to metamorphosis inside the male's vocal sac. The gastric-brooding frogs of Australia, now extinct, did something comparably strange, with the female swallowing her eggs and raising the young in her stomach. A number of other frogs guard eggs, carry eggs or tadpoles on the back or in skin pockets, or hold them in the mouth for shorter periods, but the complete vocal-sac pregnancy of the male Darwin's frog stands alone.

Why is Darwin's frog endangered?

Two forces are at work. Its forest home, the cool wet Nothofagus and Valdivian rainforest of southern Chile, has been widely cleared and replaced with fast-growing plantations of non-native pine and eucalyptus, along with pasture and towns, and the frog cannot live in those. On top of that, the amphibian chytrid fungus, which has devastated frogs worldwide, is present in the region and is strongly suspected in the disappearance of the northern Darwin's frog, last reliably seen in the 1980s. The surviving southern species now persists in scattered patches of protected or remote old forest.

What does Darwin's frog do when threatened?

It plays dead as a drifting leaf. Darwin's frog already looks like a dead leaf, with a pointed snout that mimics a leaf tip and often a straight colour boundary down the body like a leaf edge. If a predator comes close, the frog either freezes in place or, if it is near water, flips belly-up and floats motionless, letting the current carry it while it shows its dark-blotched underside. Both tricks exploit the fact that many predators ignore something that looks like dead vegetation and does not move.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 11, 2026. Last updated September 11, 2026.

Quick facts

Scientific name: Rhinoderma darwinii
Diet: Small forest-floor invertebrates hunted among moss and leaf litter, including insects, spiders, mites, snails, and worms, caught with a quick flick of the tongue, with the frog often sitting motionless disguised as a dead leaf until prey comes close
A pregnancy in the throat: The male guards the eggs for three to four weeks until the embryos begin to move, then takes them into his mouth and slides them into his vocal sac, where the tadpoles develop for several weeks, nourished by their yolk and by secretions from the sac wall, before the fully formed froglets are released from his mouth
A frog shaped like a leaf: Darwin's frog has a pointed, fleshy snout, a slender body, and brown or green colouring often split by a sharp line, and when it senses danger it freezes or flips onto its back and lies still, showing a blotched belly and looking exactly like a fallen dead leaf drifting in a stream
Collected on the Beagle voyage: The frog was collected by Charles Darwin in the temperate forests of Chile during the voyage of the Beagle in the 1830s and later named after him, and the vocal-sac brooding was described soon afterwards and astonished the naturalists of the time
Two species, one likely gone: There are two species, the southern Darwin's frog, which survives in scattered populations, and the northern or Chile Darwin's frog, which has not been reliably seen since the 1980s and is feared extinct, a loss linked to the amphibian chytrid fungus
Bound to old forest: Darwin's frog lives on the cool, humid, mossy floor of native southern beech and Valdivian forest, breeding in and beside slow, clear streams and boggy seeps, and it fares badly in the plantations of exotic pine and eucalyptus that have replaced much of that forest
Small and quiet: Adults are only about 2.5 to 3.5 centimetres long, and the male's call is a soft, short piped note that is easy to miss, so the frog is far more often found by chance than by its voice
Range: The temperate rainforests of southern Chile and a narrow strip of adjacent Argentina, roughly from around Concepcion south into the Aysen region, in native southern beech and Valdivian forest with a deep, damp, mossy floor, beside slow, cold, clear streams, seeps, and bogs, from near sea level to about 1100 metres.
Conservation status: Endangered ↓ ≈ The southern Darwin's frog is listed as Endangered and declining, with a fragmented range in southern Chile and adjacent Argentina and total numbers thought to be modest and falling. The main pressures are the clearance and replacement of native Nothofagus forest with pine and eucalyptus plantations and pasture, along with logging, fire, drainage, and introduced predators, and, critically, the amphibian chytrid fungus, which is present in the region and is the leading suspect in the disappearance of the northern species. Conservation efforts include protected forest reserves, captive breeding and reintroduction programmes in Chile and at overseas zoos, and chytrid monitoring in the wild