Corroboree frog. Image Jon Harris.
Corroboree frog. Image Jon Harris.

Names

Southern Corroboree Frog, Pseudophryne corroboree

Status

Critically Endangered (Species Profile and Threats Database by the Australian Department of Environment and Energy)

How wild horses threaten the southrn corroboree frog

The frogs breed in pools and seepages in sphagnum bogs, wet tussock grasslands and wet heath in the Snowy Mountains region of Kosciuszko National Park. In summer wild horses trample the frogs' eggs and the vegetation that protects them.

In winter, the frogs seek protection in leaf litter and dense groundcover in heath and snow gum woodland. The wild horses trample these places of refuge.

Southern Corroboree Frogs are found only in the Snowy Mountains.

Evidence

In April 2018, the NSW Threatened Species Scientific Committee  made a Preliminary Determination that habitat degradation and loss by feral horses be listed as a Key Threatening Process under the Biodiversity Conservation Act (NSW, 2016). The Committee found that the Southern Corroboree Frog is affected by changes in the quality and availability of water and by habitat degradation, both of which are caused by horses (Hunter et al. 2009). The Committee described sphagnum bogs, a primary habitat for corroboree frogs, as very slow growing and highly sensitive to disturbance and trampling (Macdonald 2009; Hope et al. 2012).

There is little doubt as to the severity of the continued decline of the southern corroboree frogs. In fact, in 2015 only four frogs - two males and two females - were found in the wild making them effectively extinct. A national recovery plan for Corroboree frogs was published in 1996. The plan blamed the frog’s initial decline mainly on a disease caused by the amphibian chytrid fungus (Batrachochytrium dendrobatidis).  Recovery actions include captive breeding and re-introduction, and protection of the places in which the frogs live from feral animals.

The introduction of captive-bred corroboree frogs into the wild involves releasing eggs into artificial pools within artificial enclosures in the frogs’ natural habitat.The pools are strong enough to exclude wild horses. It takes four to five years for the frogs to mature, so it is not yet certain that the eggs will survive to adulthood.

Further reading

https://theconversation.com/australian-endangered-species-southern-corroboree-frog-16189

https://www.theguardian.com/australia-news/2015/mar/09/back-from-the-brink-of-extinction-hunting-for-the-worlds-rarest-frog

https://www.environment.nsw.gov.au/determinations/southerncorroboreefrogFD.htm

https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10693