Fears frog population could spread

After establishing a population in Streaky Bay, an introduced species of cannibalistic frog – Spotted-Thighed Frog – could establish breeding populations in other Eyre Peninsula towns.

Researcher Christine Taylor said the Spotted-Thighed Frog (Litoria cyclorhyncha), which is native to southern parts of Western Australia, was likely introduced in South Australia by people travelling across the Nullarbor who had “stow-away” frogs in their vehicles, or was purposely introduced.

The frogs eat many types of invertebrates including spiders, beetles and other types of insects, slaters and centipedes – it also eats its own young frogs, lizards and one has even been discovered digesting a juvenile mouse. 

“Therefore the spotted-thighed frog could impact on other species of frogs or other animals by predation and competition for food and space,” Ms Taylor said.

The frogs have established a breeding population in Streaky Bay of about 1000 individuals, and Ms Taylor said there was a possibility that could spread to other towns, with frogs spotted in Ceduna, Port Kenny and at least four in Port Lincoln, with another established population in Western Australia border town Eucla.

Ms Taylor said the Streaky Bay population grew out of the artificial wetland at Streaky Bay Area School.

“There must have been a male and a female, who were able to breed, and one group of tadpoles is enough to start a population,” she said.

“The wetland at the school was suitable, it has reeds around the edge to hide in and offered plenty of food.”

She said only two frogs – a male and female – were needed to start a breeding colony in an area, although the right conditions were required, yet if that occurred it could have repercussions on the local environment.

“They may not establish new populations very easily as they would need...suitable environmental conditions to breed,” Ms Taylor said.

“They have the potential to be invasive and create an environmental impact.”

Ms Taylor said she recommended people refrain from moving the frogs around and that management strategies needed to be put in place.