The spotted tree frog with the taxonomic name of Litoria spenceri, also known as Spencer’s tree frog, is a frog species native to a small area of southeastern Australia in the province of Victoria, and to Mt. Kosiuszko in New South Wales. It was first seen in the year 1901 and then not located again for another 50 years. There are estimated to be only around 3,000 living specimens of the spotted tree frog alive in the wild as of 2005, scattered across 12 isolated regions. They usually live in mountainous areas of heavy vegetation alongside creeks and rivers. They have sometimes also been known to inhabit lower-lying, exposed terrain in the same regions.
As types of frogs go, the spotted tree frog is a relatively small sample in the family Hylidae, with adult males measuring around 2 inches (50 millimeters) in size and females about 20% larger. The colors of the frog on its back and exposed regions of limbs and head are usually a mottled olive-green or bright green mixed with some light brown or white color, and the belly and underside of the limbs ranges from orange to pale yellow or white. Evidence suggests that it prefers regions of rivers and creeks because the mottled terrain gives it good camouflage, and it needs a constant source of water. It is also known to live in trees in the mountains and the pads of its fingers and toes are sticky to enable it to climb vertical surfaces.
The diet of the spotted tree frog is largely that of insects known to inhabit wet woodland areas, such as flying insects like moths, foraging ants, or small spiders. The life span of frogs is something of a mystery as of 2011, but most are assumed to live around five to 15 years in the wild, whereas the spotted tree frog is estimated to live about 10 years. Frogs generally live shorter lives than toads, but some tree frogs can live for over 25 years, such as Litoria caerulea, or the Common Green Tree frog.
Mating for the spotted tree frog occurs in late spring and early summer, from October to December. While the frog lives in remote, mountainous areas that are rocky and largely inaccessible to larger animals, their numbers are in decline. The offspring tadpoles themselves have good camouflage markings of dark brown color with gold flecks and gold eyes to match stones in the water, and they remain motionless when predators approach. Despite this, it is believed that two of the primary causes for the decline in numbers of the spotted tree frog are the presence of introduced trout into the rivers and streams where they live, which feed on large numbers of hatched tadpoles, and disease caused by declining water quality including herbicide contamination.
While the female Spencer’s tree frog mates and lays anywhere from 300 to 1,000 eggs between shallow river or creek stones, most of these don’t survive to maturity. The Australian Environment Protection and Biodiversity Conservation Act of 1999 (EPBC) has listed the spotted tree frog as endangered. Efforts to prevent the species from going extinct include captive breeding programs, habitat restoration, and extensive research into their life cycle as of 1994.