Quokka numbers cut drastically by WA fire

Quokkas are the unofficial mascots of Rottnest Island off Perth, known for their smiling faces across social media in so-called "quokka selfies".

But the vulnerable marsupials, found on the island and in WA's southwest region, have less to smile about with new data released by the World Wildlife Fund (WWF) on Tuesday showing the devastating effect the 2015 Northcliffe bushfire had on the creatures' numbers.

Before the fire, the analysis shows, the area was home to 500 quokkas, but now only 39 can be accounted for.

Ecologist Karlene Bain said quokka numbers could be revived there if threats were well managed.

"The surviving quokkas are highly vulnerable to predators and other threats, so active management of the area is needed to help them survive," she told AAP.

Many quokkas had died in the fire but it was hoped some had fled to surrounding areas and were now living there.

Dr Bain said there were now some 10,000 on Rottnest Island and another 10,000 in WA's southwest.

Their main predators were feral cats and foxes, although feral pigs were also known to disrupt their habitats by eating vegetation.

"The main challenge is to make sure their movement patterns are not disrupted in the long term," Dr Bain said.

WWF species conservation manager Merril Halley said radio collars and sensor cameras were being used to pinpoint where quokkas were living and travelling to.