Breeding Success

Populations of Northern Corroboree Frog suffered severe declines during the 1980’s and numbers continue to dwindle. As part of a recovery program for the Northern Corroboree Frog, ecologists in the Department of Territory and Municipal Services (TAMS) collected eggs from the wild and established a captive assurance population in a biosecure facility at Tidbinbilla Nature Reserve. The facility at Tidbinbilla, is designed to keep the captive Corroboree Frog population free of infection from the deadly Chytrid fungus, that has devastated wild populations of Corroboree Frog. The aim of the program is to eventually breed and release Corroboree Frogs back into the wild to bolster wild populations.

Attempts by a number of zoos to breed the related Southern Corroboree Frog had been largely unsuccessful, highlighting the challenge of recreating the specialised breeding conditions for these frogs in captivity. After waiting four years for the frogs to reach breeding age, ecologists and wildlife officers in TAMS, successfully recreated the necessary conditions for the successful breeding of Northern Corroboree Frogs in 2008. Successful breeding has also occurred in each subsequent year since. In 2010, Taronga Zoo adopted the technique used at Tidbinbilla and successfully bred the related Southern Corroboree Frog.

Breeding and raising Corroboree Frogs in captivity, where conditions can be controlled, results in a far higher survivorship rate than in the wild. Apart from Chytrid fungus, one of the greatest sources of mortality in wild populations is variable or low rainfall. Insufficient rainfall or snow can result in eggs not hatching (because pools don’t flood the nests) or pools drying before tadpoles can metamorphose. There are currently over 1,000 Northern Corroboree Frogs in the captive population at Tidbinbilla, which is many times more than exist in the wild in the ACT (estimated to be less than 50 individuals). The first releases back to the wild are planned for late 2011.