Endangered animal populations bounce back on Kangaroo Island thanks to predator-proof fence

Vulnerable species on Kangaroo Island are bouncing back thanks to a 380-hectare "predator-free" enclosure erected by the Australian Wildlife Conservancy.

It has been five years since the Western River Refuge was enclosed by a cat-proof fence.

Australian Wildlife Conservancy principal ecologist Pat Hodgens is surprised at how well vulnerable species within the refuge are faring.

He estimated species such as the Kangaroo Island dunnart have increased in numbers by 90-100 per cent.

Mr Hodgens was unable to provide an accurate pre-bush fire estimate as to the exact numbers and has previously said the dunnart was notoriously difficult to survey because of its size and shy temperament.

"So the dunnart has fared a lot better than I think a lot of people thought [they would] … especially me, six years ago," he said.

"There are still dunnarts outside of the fence in pretty good numbers, but we are definitely seeing a steady consistently higher activity level of dunnarts within the fence versus the outside."

Experts were shocked at the reappearance of birds such as the western whipbird in the wake of the devastating fires.

But Mr Hodgens said its numbers have also jumped by roughly 100 per cent.

"The western whipbird and also the Bassian thrush … these birds are also really predated upon by feral cats," he said.

"We didn't have any of those birds living within the feral cat exclusion fence at the time of construction, but they've found their way back there."

Good timing

Mr Hodgens said the Western River Refuge project was intended to be an experiment.

But in the wake of the bushfires the project went from an experiment to "a rescue mission".

"We knew that the impacts were going to be pretty massive, so we set to work pretty quickly to basically survey in the days and weeks after that fire," Mr Hodgens said.

With more than 90 per cent per cent of the habitat of vulnerable species on Kangaroo Island destroyed, native species struggled to survive.

"We also saw that there was huge amounts of feral cats moving across the fire scar at that point and finding these little unburnt patches and then basically predating upon everything that they could find within it," Mr Hodgens said.

Fearing that truly eradicating feral cats broadly from Kangaroo Island was not possible, the Australian Wildlife Conservancy instead decided to put up the cat-proof fence around a known population of dunnarts while removing feral cats during its construction.

Mr Hodgens said the decision proved vital for many predated native animals.

Cultural impact and knowledge

Ngarrindjeri elder Mark Koolmatrie, who runs cultural tours on Kangaroo Island, says he is excited to see strong numbers return.

"We need these native species to come back … because they belong to the place," he said.

"People have looked for a solution rather than concentrating on the problem."

For Mr Koolmatrie, restoring the land goes beyond improving the island's biodiversity.

He said it was a job for the Ngarrindjeri People and other Kangaroo Island inhabitants.

"We are the original custodians … I think what's really important is for people to work with Ngarrindjeri," he said.

"What we want to do is restore and we want to work alongside islanders.

Mr Koolmatrie said bringing traditional methods of land management "into a new world" through collaboration would "make sure that this environment bounces back".

"This is the start, not the finish," he said.