Spotted-Thighed Frog A Threat To South Australia Native Species

The introduced amphibian has become established in South Australia's Streaky Bay
Spotted Thigh Frog
The spotted-thighed treefrog has been documented eating its own kind. Photo by Christine Taylor
Spotted thighed treefrog

The spotted-thighed treefrog (Litoria cyclorhyncha), an amphibian that is native to southern Western Australia has made its way to South Australia by humans and has the potential to wreak havoc on native species. A paper published in the Australian Journal of Zoology examined the diet of the frog and found that it is quite the voracious eater. The scientists examined 76 frogs from three habitats in Australia’s Streaky Bay and found beetles, birds, lizards, spiders, mice, and even their own species, showing that they are cannibalistic.

The study noted that on average, each frog had at least six prey items in its stomach, including native geckos.

“This frog is an indiscriminate eating machine that will devour just about anything it can fit into its mouth,’ Christine Taylor, a co-author of the study said in a news release put out by the University of South Australia. “We’re talking about a relatively large, predatory tree frog that, as a species is alien to South Australia, and it could have devastating impact on invaded habitats. As it eats away at local species, it’s impacting the natural ecosystem, which can displace or destroy local food webs, outcompete native birds, reptiles and mammals for resources, and potentially change natural biodiversity.”

Spotted Thigh treefrog

Spotted-thigh treefrogs are so named due to the yellowish spot on their thighs. Photo by Christine Taylor

Taylor noted that if there is any other population outside of Streaky Bay, where they have become established, it would be due to movement of the frogs by people.

“The spotted-thighed frog is obviously very mobile. Already it’s managed to travel more than 2000 kilometers and set up a colony in Streaky Bay. But its considerable tolerance of salinity and potential ability to withstand high temperatures could lead to further geographic spread, and if not controlled, it could extend further eastward into the Murray-Darling Basin,”  Associate Professor Gunnar Keppel said. “It’s vital that we continue to protect Australia’s biodiversity. Preventing further dispersal of the spotted-thighed frog is a high conservation priority. The state government should consider managing the invasive population of spotted-thighed frogs at Streaky Bay. This should include education programs to inform people about what to do if they find a frog, as well as the feasibility of exterminating the population in South Australia.

An abstract of the paper, “Indiscriminate feeding by an alien population of the spotted-thighed frog (Litoria cyclorhyncha) in southern Australia and potential impacts on native biodiversity,” can be viewed on the Australian Journal of Zoology website.

Spotted-thigh Treefrog Description

Spotted-thigh treefrogs are so named due to the yellowish spot on their thighs. The amphibian is dark green or brown in coloration and the males grow to about 65 mm while the females grow to 85mm. It is native to southern Western Australia with an established introduced population on the Eyre Peninsula in South Australia.

Categories: Frog & Amphibians Information & News