Some of Sydney’s koalas are facing an uncompromising dilemma.
The koalas living in one corner of Australia’s largest city are perilously inbred, researchers report February 26 in Conservation Genetics. But the solution — interbreeding with neighboring koala populations — risks introducing the koalas to a deadly sexually transmitted disease.
In 2021 and 2022, University of Sydney conservation biologist Carolyn Hogg and her colleagues determined that koalas in the southwestern Sydney metro area had the lowest genetic diversity anywhere in the state of New South Wales. To investigate further, the researchers caught 111 wild koalas (Phascolarctos cinereus) from seven sites across the forested region south of Sydney and collected ear tissue