Thousands of corroboree frog eggs released in fight to save endangered species

Hopes species will recover as eggs bred in captivity at Taronga Zoo in Sydney and Zoos Victoria enter the wild

Scientists say that without a captive breeding program the critically endangered corroboree frog would be two years from extinction. Photograph: John Lane/Zoos Victoria

Michael Slezak

Tuesday 26 April 201608.17 BST

After 10 years of captive breeding, the critically endangered corroboree frog   might be on its way back from the brink of extinction.

Fewer than 50 mature corroboree frogs live in the wild in alpine New South Wales and scientists have estimated that without a captive breeding program that began 10 years ago they would be a mere two years from extinction. In fact, most of the frogs currently in the wild are the result of previous captive releases.

But, this month, thousands of eggs bred in captivity at Taronga Zoo in Sydney andZoos Victoria are being released into the wild – the largest release to date.

Last week the first batch of about 1,850 was released, with the rest planned for release in coming weeks.

“The eggs we released this month will take six months to metamorphose into frogs and then a further four years for them to mature,” said Taronga native fauna curator Michael McFadden. “It’s hoped that these eggs will contribute to giving this species a chance to recover.”

The team released some of the eggs into raised pools that have been constructed to keep the deadly chytrid fungus out. Others were released into natural pools in areas that are known to have low levels of the fungus and others were released into enclosures.

The fungus causes a disease called chytridiomycosis on the skin that fatally impairs frogs’ ability to maintain electrolyte, water and oxygen levels.

McFadden told Guardian Australia the program appeared to be working, since most of the adult frogs they saw in the wild were in areas where they were previously extinct but have since been reintroduced.

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