Frogs of Western Australia

1st July 2022

Our speaker was Paul Doughty, Curator of Herpetology at the WA Museum, whose interests are mainly frogs and geckos. He focused on the frogs of the Southwest. He said frog species are relatively easy to distinguish because, as a rule, you can use the calls instead of the appearance.

There are about 40 species of frog in the Kimberley and 30 species in the Southwest, with smaller numbers in the drier areas. Paul talked about autumn, winter, and spring breeders in the Southwest in that order.

The Hooting Frog Heleioporus barycragus is a large burrowing frog with a long burrow in which it builds a foam nest. The five species of Heleioporus lay their eggs in the autumn before it rains and wait for the burrows to be flooded. The tadpoles hatch and swim out of the burrow. Other autumn-breeding frogs are the Crawling Frog Pseudophryne guntheri and the Ticking Frog Geocrinia leai.

The Quacking Frog Crinia georgiana is a winter-breeding froglet that breeds around soaks, which Paul described as a weird froglet because of its crazy mating behaviour. In most other Crinia, mating takes a day or two. But in this species, there is often frenzied activity with male-male wrestling, and several males will mate with a female simultaneously. Other winter-breeding frogs are the Slender Tree Frog Litoria adelaidensis and the Western Banjo Frog Limnodynastes dorsalis.

The spring breeders are mostly found near the south coast. They include the four species of Anstisia. These used to be Geocrinia, but they differ by laying few eggs, and the tadpoles hatch into a nest they don’t leave and have vestigial mouths. They are A. rosea and A. lutea and the endangered species A. alba and A. vitellina. There is also the Sunset Frog Spicospina flammocaerolea, the monotypic species that lives in peat swamps of the extreme Southwest and was discovered in 1994 by Pierre Horwitz [correction from talk]. It is shy and hard to survey, and the zoo has a captive breeding program in response to its declining population.

The Turtle Frog Myobatrachus gouldii calls after the summer rain. This Southwest endemic does not need free water; it has pink skin, a streamlined head and strong front legs for “swimming” through the sand. The female lays eggs in moist sand, and the tadpole lives entirely within the egg until it hatches into an adult frog. There are several other frogs in the Southwest with this feature, which is called direct development.

Paul provided a preview of taxonomic name changes, including the Motorbike Frog Litoria moorei and a sneak peek at new species. He concluded with the hugely popular citizen science app called FrogID. Download the app, record the call, and send it to the Australian Museum for identification. While you learn about frogs, you provide useful data for herpetologists.

Mike Gregson