<P> Corroboree frogs are the first vertebrates discovered that are able to produce their own poisonous alkaloids, as opposed to obtaining it via diet as many other frogs do . The alkaloid is secreted from the skin as a defence against predation, and potentially against skin infections by microbes . It has been described as potentially lethal to mammals if ingested . The unique alkaloid produced has been named pseudo-phrynamine (Daly et al. 2002). </P> <P> Corroborree frogs are quite unusual in their nature . Not only do they not start breeding until four years of age, they also hibernate during winter under whatever shelter they can find . This may be snow gum trees, or bits of bark or fallen leaves . Males stay with the egg nests and may breed with many females over the course of one season . </P> <P> The southern corroboree is recognised as being critically endangered with fewer than 200 individuals left in the wild in recent years . The northern species is listed as endangered . </P> <P> The southern corroboree frog was considered relatively numerous within its very small distribution in the 1970s, as of June 2004 it had an estimated adult population of 64 . This species has suffered declines of up to 80% over the past 10 years . It is found only within a fragmented region of less than 10 km2 within Mount Kosciuszko National Park in the Snowy Mountains in New South Wales . It is only found at 1300 m above sea level (Osborne 1989). It is currently listed as critically endangered and is considered to be one of, if not, Australia's most endangered species . </P>

How many corroboree frogs are left in the wild in australia