Finally, some good news for Australia’s favourite tree-hugging marsupials.

Troubled by chlamydia and habitat destruction, some local populations have become critically endangered or even extinct, leaving conservationists concerned about inbreeding.

But according to the first large genomic study of koala populations, the animals (Phascolarctos cinereus) are happily breeding with neighbouring groups.


So much so that any suggestion there are three “subspecies” of isolated koala populations doesn’t pan out.

Sequencing the genomes of 171 koalas from eight regions along the east coast of Australia, the main koala habitat, Herman Raadsma at the University of Sydney and colleagues found no evidence of inbreeding.

“The bottom line is it’s not desperate,” says Raadsma. He adds that the koalas should continue to inter-breed as long as corridors link the different populations.

William Sherwin, at the University of New South Wales in Sydney, says it was “high time” that someone did this research into koala populations.

But he says inbreeding does seem to be an issue in some very isolated island populations that weren’t included in the analysis.

Raadsma says although relocating koalas should always be a last resort, this shows it might be an option to protect the more isolated populations from inbreeding.

Since koalas from different parts of Australia appear quite different, some researchers have classified them into three separate subspecies – visibly distinct populations that could interbreed but don’t.

On the contrary, Raadsma has found more genetic diversity within populations than between them, so there seems to be a series of slightly different interbreeding populations inside a single species, rather than any specific subspecies.

Journal reference: Conservation Genetics , DOI: 10.1007/s10592-015-0784-3

(Image: Shin Yoshino/Minden Pictures/FLPA)