Amphibians
Red-spotted Toad
Anaxyrus punctatus · also called red-spotted toads
A red-spotted toad can complete an entire breeding cycle in a rock pool barely large enough to notice, a rare skill in a desert where water rarely sticks around for long. Its skin is covered in small warty tubercles tipped in red or orange rather than the large glands most toads carry, and a flattened body lets it squeeze into narrow rock crevices to escape the worst of the heat.
Overview
The red-spotted toad, Anaxyrus punctatus, is a small amphibian of rocky desert, canyon, and lower mountain habitat across the southwestern United States and Mexico. It hunts ants and other invertebrates at night, sheltering in rock crevices through long dry spells.
Built for the smallest puddle
Breeding opportunistically in even the tiniest, shortest-lived rock pools after rain, the species times its reproduction to make the most of unpredictable desert water. A high-pitched, musical trill from calling males usually signals a pool has formed nearby.
Status
Least Concern — common and widespread across suitable rocky desert habitat, well adapted to the extreme dryness and unpredictable rainfall of its range.
Red-spotted Toad: common questions
Why does the red-spotted toad have small red-tipped warts instead of large glands?
Rather than the large, prominent parotoid glands found behind the eyes in many other toad species, the red-spotted toad instead has numerous smaller warty tubercles distributed across its body, many tipped with a distinctive reddish or orange colouration, a different arrangement of skin glands that still likely serves a similar defensive function while giving the species its own recognisably distinct appearance and common name.
How can a toad successfully breed in such tiny pools of water?
The red-spotted toad has adapted its reproductive timing and tadpole development to work within the constraints of small, shallow, often short-lived rock pools and temporary desert water sources, breeding quickly after rain and completing larval development relatively rapidly to take full advantage of even very limited and unpredictable water availability before it potentially evaporates.
Why is the red-spotted toad's body shape different from other toads?
Its notably small, somewhat flattened body shape is thought to be an adaptation that allows the species to squeeze into narrow rock crevices for shelter, providing protection from extreme desert heat, dryness, and some predators, a body plan well suited to the rocky, crevice-rich desert and canyon habitat the species favours compared with more open desert terrain.
How does the red-spotted toad survive long dry periods in the desert?
The species shelters in rock crevices and burrows during extended dry conditions, reducing activity and water loss until suitable rainfall creates temporary pools and increases humidity, at which point it emerges to feed and breed opportunistically, a boom-and-bust activity pattern well suited to surviving the unpredictable rainfall typical of its arid desert and canyon range.