There are an estimated three times as many feral cats in Victoria's Otways region than the national average, according to new research from the University of Melbourne.

Key points: Victoria's Otway forests look pristine, but research suggests feral cats pose a high, but hidden, risk to native wildlife

Victoria's Otway forests look pristine, but research suggests feral cats pose a high, but hidden, risk to native wildlife In July 2018, the State Government declared feral cats as a pest animal and began developing a code of practice to manage the population

In July 2018, the State Government declared feral cats as a pest animal and began developing a code of practice to manage the population Researchers say bounties on cats help, but are not the silver bullet

PhD candidate Matthew Rees from the School of Biosciences has placed 240 motion-sensing cameras at two sites in the western Otways region prior to and after the introduction of fox baiting in November 2017.

Mr Rees said he was measuring the impact of fox baiting and whether fewer foxes would result in more cats.

"If we take out foxes from the landscape which are a higher order predator than feral cats, they're bigger, bit scarier, what happens to the feral cats?"

It is estimated that feral cats kill millions of reptiles and birds in Australia annually, with critically-endangered species like the mountain-pygmy possum, helmeted honeyeater, orange-bellied parrot and plains wanderer at particular risk.

Feral cats pose hidden threat

Mr Rees said fox numbers seemed to be coming down after baiting was introduced to some parts of the Otways in 2017 but that feral cats were thriving with an estimated one per square kilometre.

"The simplest explanation would be that this is a forest which is really productive, it has continuously high rainfall so it has lots of prey for cats to eat," he said.

Feral cats prey on endangered native wildlife like the mountain-pygmy possum, helmeted honeyeater, orange-bellied parrot and plains wanderer. ( Supplied: Matthew Rees )

"When there's heaps of prey to eat, feral cats tend to have smaller home ranges and they're more happy to share the area with other feral cats."

Mr Rees has used the cameras to identify individual cats and monitor their movements.

"I look for different patterns in their coat markings, different shapes and scars, and identify individual feral cats, and then track their movements throughout the bush," he said.

While the region looked pristine on surface level, Mr Rees said the research suggested feral cats posed a high, but hidden, risk to native wildlife.

"These feral cats are so cryptic, they're so adverse to humans, so it's really easy for them to be out of sight and out of mind," he said.

Calls for better management of feral population

Research manager Jack Pascoe from the Conservation Ecology Centre in the Otways said the research confirmed what they had seen anecdotally.

"We have lots of other camera monitoring programs which measure activity levels, but nothing that's gone into the level that Matt's been able to do," Dr Pascoe said.

In the prey-rich rainforest region of the Otways, feral cats appear to be less territorial. ( Supplied: Matthew Rees )

In July 2018, the State Government declared feral cats as a pest animal and began developing a code of practice to manage the population.

"It really means feral cats in public lands are able to be destroyed and really the only management options available now since the legislative change, is cage trapping for cats and euthanising those animals," Dr Pascoe said.

"It's incredibly labour-intensive and probably not a method that's gonna have landscape-scale population effect."

Dr Pascoe said there needed to be a clear code of practice for managing feral populations, including potentially baiting cats as was done with foxes.

"We don't really have methods to control cats effectively across large landscapes," he said.

"Bounties have been successful to a degree with wild dogs and foxes, but it's a big problem in very remote areas when we're looking at cats.

"Bounties, while they may be helpful in certain circumstances, probably aren't the silver bullet."

A spokesperson for the Department of Environment, Land, Water and Planning said the code of practice was still being developed in consultation with animal welfare organisations, including Animal Welfare Victoria and the RSPCA.

"All Crown land managers undertaking feral cat control will be required to abide by the code of practice."