DAVID GREENE, HOST:
Australian magpies are known for being able to mimic the sounds they hear in the environment. For one bird in Australia, its songs in recent times have turned to sirens, replicating the noise of fire engines.
(SOUNDBITE OF BIRD SONG)
STEVE INSKEEP, HOST:
A sign of just how bad the destruction is. Bushfires are profoundly affecting Australia's wildlife.
CHRIS DICKMAN: We're probably seeing the worst fire season for the native animals here that we have on record.
GREENE: Chris Dickman is an ecology professor at the University of Sydney. He estimates that almost a billion animals have been killed, including bats, frogs, fish, birds and reptiles.
DICKMAN: These species are likely to decline to very low numbers and probably local extinctions that we can expect as a consequence. And many of these species, as well, are really important from an ecological point of view.
INSKEEP: Consider koalas. They normally thrive in the state of New South Wales, which has been hit hard by fire. Australia's environment minister estimates that 30% of all koalas in that region may have been killed.
GREENE: Ros Irwin is the president of Friends of the Koala. They've been taking in rescued koalas. She says that in addition to the threat posed by the fires, a drought is drying up the eucalyptus trees. That's the animal's main source of food.
ROS IRWIN: They've come down from their trees and just sat there because they can no longer climb and maintain themselves. So we get a lot of koalas coming in that are simply malnourished, as well as dehydrated.
INSKEEP: Irwin says a rescue team of volunteers is now on call 24/7.
IRWIN: It's just constant, quite frankly. It's a work of love, really, because that's what drives people to do it. We care about our wildlife, and we want to be able to save them.
INSKEEP: Her group has been going on several rescue missions per day and now has about 45 koalas in their care.
IRWIN: That's a lot. That's the most we've ever had.
GREENE: Irwin says it is still too soon to know the exact toll the fires will have on Australia's koalas, but she is deeply worried.
IRWIN: Certainly, there will be many places where there will be just silence and no wildlife at all for a long time, I think.
GREENE: She's just not sure whether the species and Australia's other treasured animals will ever be able to really come back from this.
(SOUNDBITE OF AKIRA KOSEMURA'S "OUT OF THE SOLITARY MIND") Transcript provided by NPR, Copyright NPR.