Western ringtail possum's endangered status blamed on feral cats and foxes

Western ringtail possums have been placed on the endangered list, with some studies estimating there are as few as 8,000 adults of the species in the wild.

The species’ status was changed from vulnerable to endangered, the second highest risk level, in the annual review of the Western Australian threatened species list, announced by the state’s environment minister, Albert Jacob, on Tuesday.

The possums live in three isolated pockets in south-western WA: the Swan coastal plain, near Busselton; the southern forests, near Manjimup; and the south coast, near Albany.

Dr Ken Atkins from Parks and Wildlife WA told Guardian Australia the Action Plan for Australian Mammals recommended the possums be listed as critically endangered, the highest level of risk, based on studies of the southern forest and Busselton populations.

“We decided that it was getting close to critically endangered, but taking a conservative approach it was still in the endangered category,” he said.

Atkins said one study of the southern forests population showed an 80% decline in numbers over the past 10 years, which it attributed to feral cats and foxes.

There are no firm numbers for the Busselton and Albany populations, but Atkins said both areas suffered from habitat destruction as land was cleared for housing developments.

Suitable possum habitat in the Busselton region has declined to just 6.6% of pre-European settlement levels.

Encroaching property developments bring another threat for the possum – predatory pets.

“If the trees are not close enough together that the possums can travel from tree to tree through the canopy then they have to come to the ground, which makes them vulnerable to cats and dogs,” Atkins said.

Western ringtail possums are slightly smaller than their eastern cousins. The common ringtail weighs up to 1.3kg and is 40cm from nose to tail.

Nine species were added to the WA threatened species list this year, bringing the total to 669.

Peter Robertson from the Wilderness Society of WA said the possum should have been marked as critically endangered, and accused the WA government of downplaying the seriousness of the species’ decline.

Robertson accused Jacob of “paying lip service” to some of the threats facing western ringtail possums, naming climate change, frequent fires from prescribed burning and habitat loss.

“Unless each of these critical threats are addressed urgently, the possums will become extinct, with or without the promised cat baits,” he said.

Jacob said a recovery plan was in place for the possum.