Over the past 30 years, dramatic declines in frog numbers have been reported around the world. They are facing the single biggest species extinction crisis since the age of dinosaurs. Four Australian frog species have become extinct and another 15 are currently endangered.
Three frog species endemic to Western Australia are listed as ‘threatened’ by the IUCN:
- the White-bellied Frog (Geocrinia alba) is Critically Endangered
- the Orange-bellied Frog (Geocrinia vitellina) is Vulnerable
- the Sunset Frog (Spicospina flammocaerulea) is Vulnerable
The main threats to Australian frogs include habitat destruction/degradation, agricultural herbicides/pesticides, introduced predatory aquatic species (e.g. mosquito fish, trout), climate change and the amphibian Chytrid fungus (which has been linked to severe amphibian population declines and extinctions around the world).
Breeding for Release
As part of conservation efforts for our threatened native frog species, a breeding and research program was established at Perth Zoo. This program began in 2005 with a focus on research to underpin the development of successful rearing, breeding and management techniques for frogs and the establishment of insurance populations of selected Western Australian species.
Perth Zoo initially investigated the reproductive biology and husbandry requirements of three non-threatened Western Australian frog species (Roseate Frog, Cave-dwelling Frog and Weigel’s Toad). This allowed staff to gain valuable experience keeping, breeding and rearing frogs before shifting the program focus to the three threatened species.
The White-bellied and Orange-bellied Frogs are currently the focus of ‘head-starting’ (protected rearing) and breed-for-release programs at Perth Zoo. The head-starting program involves collecting egg-nests in the wild and rearing them in a predator-free, protected environment at Perth Zoo to increase their chance of reaching adulthood.
Since 2008, Perth Zoo has successfully reared White-bellied Frogs from egg nests collected from the wild as well as had 7 hatched and successfully reared from breeding activity at the Zoo in 2012 (a world first). Since 2010, more than 550 have been released into Western Australia’s south-west in locations where this critically endangered species had become locally extinct.
The Orange-bellied Frog is closely related to the White-bellied Frog but is proving more difficult to rear and breed. Still, since 2011, over 420 Orange-bellied Frogs have been released into the wild and this year we had our first Orange-bellied Frog eggs laid at the Zoo – a world first!
Sunset Frogs were initially brought to the Zoo to improve our understanding of the species and its breeding biology should their conservation status (currently listed as Vulnerable) worsen. In 2011, after successful holding and breeding protocols were established, 30 Sunset Frogs and 251 Sunset tadpoles were released at a swamp near Walpole in the south-west of Western Australia.
Partners and Supporters
The frog breeding and rearing program is run by Perth Zoo in partnership with the Western Australian Department of Parks & Wildlife and University of Western Australia. The original research phase was funded through a grant from the Western Australian Office of Science and Innovation. The breeding and rearing program has been partly funded by Department of Parks and Wildlife and the South West Catchments Council as well as small grants from Perth Zoo’s Wildlife Conservation Action fundraising program and the Zoo and Aquarium Association.