Baw Baw frog


The Baw Baw frog is a critically endangered species of Australian frog as categorised on the IUCN Red List and listed under the Flora and Fauna Guarantee Act. It has suffered a decline in population, mostly due to infection caused by chytrid fungus. Zoos Victoria have undertaken a breeding program to ensure survival of the species which commenced in 2010, and in October 2018 has successfully collected the first eggs laid in captivity.

Taxonomy and etymology

The species was described as Philoria frosti by Walter Baldwin Spencer in 1901, honouring Charles Frost, an Australian naturalist. The specimens used in the species description were provided by Frost, an amateur herpetologist, who recovered five individuals that had been regurgitated by a tiger snake Notechis scutatus.

Description

Adult length is between 42 and 55 mm. Adults are dark brown and often have brown to dark brown, yellow flecked bellies. These frogs have a prominent parotoid gland behind each eye. Their toes are unwebbed. At hatching, the tadpoles are creamy white and unpigmented, acquiring some colouration and eye pigmentation as they mature. Tadpoles have large yolk sacs and residual mouths, and do not feed until metamorphosis. Metamorphlings have different colouration to the adults.

Declining population

Population estimates have reduced from 15,000–10,000 breeding males in 1983 to around 750, or according to Frogs Victoria less than 250 individuals. The cause of this reduction is most likely due to chytridiomycosis caused by chytrid fungus, which can cause swift declines in an amphibian populations living in a pristine environment with no other explanation.

Captive breeding program

In order to save the frog from extinction, a self sustaining captive breeding program was commenced with Zoos Victoria taking the lead. When the program was started in 2010 almost nothing was known about managing the frogs in captivity.
An artificial environment was created in a shipping container named "the Baw Baw Bunker" and the first eggs were collected from the wild in 2011 but were unviable. In 2013, 96 metamorphs were raised from collected eggs. Eleven females were captured from the wild in 2016 for the first time, and on the 22nd of October 2018 the first eggs were laid in captivity. Researchers hope to place the eggs on a chytrid fungus free part of Mt Baw Baw within 4 weeks.