Overview
The Spotted Tree Frog (Litoria spenceri) is an exquisite, river-dwelling amphibian tightly tied to the roaring, crystal-clear torrents of southeastern Australia’s alpine foothills. Sporting heavily textured, warty skin splashed in shades of mossy green and slate grey, this agile climber spends sunny days basking atop river boulders just inches above surging rapids, perfectly camouflaged against granite stone.
Biology and Physical Characteristics
Litoria spenceri features a slender, streamlined build with extraordinarily muscular hind legs designed for leaping between slick river rocks. Its dorsal skin is coarse and warty, mottled in earthy tones of slate grey, olive green, and chocolate brown with irregular darker spots. Its fingers and toes end in expanded suction discs that provide infallible grip on wet, algae-covered boulders, complemented by fully webbed feet suited for swimming through powerful currents.
Behavior and Ecology
Unusually for Australian hylid frogs, the spotted tree frog is diurnal, actively basking in direct sunlight on sun-warmed river stones to elevate its body temperature and combat fungal pathogens. Males call from stream margins between October and December, emitting a quiet, rhythmic pulsing call often drowned out by rushing water. Females lay clutches of 200 to 1,000 adhesive eggs hidden beneath submerged stones in deep pool currents, where streamline-bodied tadpoles cling to rocks to graze epilithic algae.
Conservation and Human Impact
Evaluated as Critically Endangered, the spotted tree frog has suffered catastrophic local extinctions since the 1980s. The devastating amphibian chytrid fungus (Batrachochytrium dendrobatidis), combined with heavy predation on tadpoles by introduced brown and rainbow trout, eliminated over half of all known historical stream populations. Zoos Victoria conducts high-priority captive breeding, reintroduction, and trout exclusion programs across Gippsland rivers to stabilize the species.
Interesting Factoid
Unlike most frogs that hide in darkness, the Spotted Tree Frog loves soaking up the hot sun on slippery river boulders right beside roaring mountain rapids, using suction-cup toes to keep from being washed away.
Last updated: October 2026