On Endangered Koalas, Scientists Hit on 'Way to Bring Them Back'

Two months after Australia declared koalas as endangered across much of the country's east coast, researchers are hoping to stock up on frozen koala sperm. Scientists at the University of Newcastle in the southeastern state of New South Wales have proposed the creation of a lab to store that sperm, which would then be used in a captive breeding program, per the BBC. The World Wildlife Fund-Australia estimates as few as 50,000 koalas remain in the wild—about half the population of 20 years ago. A 2021 inquiry found koalas would be extinct in NSW by 2050 without urgent action, following bushfires that killed 5,000 in the state over the Australian summer of 2019-20, per the BBC.

At present, "we have no insurance policy against natural disasters like the 2019-2020 bushfires that threaten to wipe out large numbers of animals at the one time," Dr. Ryan Witt says in a release. The sperm lab would provide a "way to bring them back" from extinction while improving genetic diversity, Witt adds. "We can cryopreserve koala sperm, just like we do for humans," researchers write of the model published Tuesday in the journal Animals. It notes "biobanking" would be up to 12 times cheaper than existing captive koala breeding methods, which require large colonies to prevent inbreeding. Witt says the frozen sperm would be "used to impregnate female koalas in breed-for-release programs," per the release.

"Recent advances have shown us that artificial insemination using fresh and chilled sperm works in koalas," says Dr. Lachlan Howell, lead author of the modeling research. "The hurdle is trying to freeze sperm and make use of it." The model follows Monday's announcement from NSW's environment minister of $193.3 million in funding for koala conversation over five years, per the Guardian. The animals—which the federal government shifted from "vulnerable" to "endangered" in the Australian Capital Territory, Queensland, and New South Wales in February—face additional threats from "land-clearing, drought, disease, car strikes, and dog attacks," according to the WWF. (More koala stories.)