英语听力：自然百科 澳洲夜宴蛙

The tiny northern corroboree frog of Australia is only just hanging on. Populations of both the northern and southern corroboree frogs have declined catastrophically in the wild over the last two decades. The primary culprit is the deadly chytrid fungus which has devastated frog populations across the world.

The corroboree frog suffered another crippling blow in 2003 when bushfires destroyed most of thealpine habitat the frogs called home. The loss of habitat due to drought and human-introduced animal grazing has also negatively impacted the frog populations. With fewer than 100 breeding pairs remaining in the wild by 2008, it's estimated the northern corroboree frog has become virtually extinct in the Australian Capital Territory.

“Corroboree frogs are fascinating species. They only occur in the high altitude areas of the Australian Alps, nowhere else in the world. And their bright colorings, we believe, serve as a warning signal to other animals. Black and yellow in the environment is generally a warning color. They have chemicals in their skin that show affinities to the poison arrow frogs in other countries. We don't think they are poisonous, but they are certainly taste bad.”

If current trends continue, experts believe the species faces the real threat of extinction in the next five to ten years. Last year, government scientists made a breakthrough. At Tidbinbilla Nature Preserve, they bred the frog in captivity for the first time, producing around 100 frogs. This year they produced 1,000 precious eggs, and most have begun hatching into tadpoles. Experts are optimistic. They believe the long-term survival of this species is looking much brighter.

“And if current trends continue, we think that species faces the real threat of extinction in the next five to ten years. So this population is key to the survival of the corroboree frogs in the wild.”

It's a painfully slow process. Corroboree frogs produce only about 25 eggs a year, compared to the 20,000 made by Cane Toads. The success of the captive population gives new hope to the species.

“This captive population does that. It buys us time. It gives us a window of opportunity that we can help overcome the effects of this deadly disease.”

The ultimate goal of the breeding program is to release the frogs back into the wild within the next two years.