The endangered amphibians are the offspring of six adults and 20 tadpoles taken from Guy’s Forest Creek, in the Upper Murray, after the 2006 fires.

At the time there were concerns for their survival as a result of the blaze and prolonged drought.

But last night the “randy” offspring were to be released on dusk.

Ten boxes of about 50 frogs, male and female, were to jump straight into the breeding cycle, a cycle that will see the males die after their job is done.

Department of Sustainability and Environment’s flora and fauna expert Glen Johnson says as many as half will perish.

“If we get 50 per cent survivorship that will be a good result,” he said.

“These frogs need flowing streams, so if they start laying eggs immediately we should see the results by the end of December and even if it is another dry summer we should be able to extend the life of that frog population for another two years.”

Booroolongs are a medium-sized tree frog that live along permanent streams that run through wet and dry forests, woodlands and cleared grazing land.

They generally live on the river pebbles on the banks of lowland streams that run west from the Great Dividing Range.

Mr Johnson says the Booroolong’s decline is the result of habit degradation and disease.

“In the Upper Murray they have only just survived the prolonged drought,” he said.

“The release of the captive-bred frogs will repopulate upper sections of the creek most impacted by the drought.”

Gerry Marantelli, who manages the Amphibian Research Centre at Werribee where they were bred, said the freed frogs had their best sexy voices on.

“These frogs are about nine months old and ready to breed, you can tell by the way they are calling,” he said.

“The males will go into a breeding frenzy and then die, so they are short-lived and that is part of the reason why any interruption to their breeding cycle, like the drought or fires, can be catastrophic.”