Guest post by Tiffany Kosch, Postdoctoral Research Fellow at James Cook University
Southern corroboree frogs (Pseudophryne corroboree) are considered Australia’s most iconic amphibian due to their bright black and yellow coloration. What most people may not realize is that this frog is nearly extinct in the wild. Surveys conducted this year at Kosciuszko National Park found less than 50 frogs remaining. This beautiful frog is susceptible to the amphibian chytrid fungus (Batrachochytrium dendrobatidis). The chytrid fungus was introduced into the corroboree frog habitat in the 1980’s causing this species to decline steadily until the present day where it would be extinct if not for human intervention. Luckily for corroboree frogs, their declines were noticed right away by scientists, and a captive breeding and reintroduction program was initiated by the Amphibian Research Centre, Taronga Zoo, and Zoos Victoria. Earlier this year, the corroboree frog captive breeding program released over 2000 eggs into the wild.
Southern corroboree frog. Photo: Corey Doughty
Captive breeding programs are often necessary for saving species from extinction. However, they are often fraught with challenges, especially if the original threat is still present in the environment as in the case of the chytrid fungus. Not all frogs are susceptible to the disease, and in fact some species such as the common eastern froglet (Crinia signifera) can harbour the disease without any obvious signs while at the same time spreading the disease like a “typhoid Mary”. This is one of the main challenges of saving the corroboree frog. Even though many frogs are being released into the wild it is believed that many of these frogs are succumbing to the chytrid fungal disease before they reach adulthood.
One way to circumvent this is to increase chytrid immunity in the corroboree frog. Our lab at James Cook University is currently raising funds through crowd funding to initiate a project to do just this. We will begin by developing a genetic test to screen frogs in the captive breeding program for genes that make them immune to the fungus. We will then use this information to selectively breed chytrid resistant corroboree frogs for release into the wild. Our goal is to enable self-sustaining populations of the corroboree frog so that future generations can observe this charismatic amphibian.
To donate to our campaign please see: https://experiment.com/projects/increasing-host-resistance-to-combat-disease-causing-mass-amphibian-extinction
Here are some helpful links to find out more about corroboree frogs and chytrid fungus: https://www.theguardian.com/world/2016/apr/26/thousands-of-corroboree-frog-eggs-released-in-fight-to-save-endangered-species
Post author Tiffany Kosch holding a southern corroborree frog.
Photo: Corey Doughty