Island dunnarts bounce back after blazes

On the fire-scarred western side of Kangaroo Island, critically endangered dunnarts have been at it like rabbits.

The need to breed at speed is a survival response for the tiny, carnivorous marsupial, which was pushed to the brink three years ago when the Black Summer fires tore across half of the island.

In immediate aftermath ecologists feared it was game over for the South Australian island's distinctive dunnart species, found nowhere else on earth.

"Basically its whole range was almost entirely burnt within a matter of days, a matter of weeks," said Pat Hodgens, who works with the Australian Wildlife Conservancy.

He remembers flying over known population sites and feeling crushed by what he saw. No trees. No bushes. Only naked ground and ash.

"You looked at it and thought that fire would have killed anything in its path."

Camera traps were hastily erected and against all expectations, soon began to capture the first tentative forays of dunnart survivors that had apparently weathered the firestorm in underground burrows.

"They were within this very small patch of unburnt vegetation. It was fantastic," Mr Hodgens said. 

"But when we found those dunnarts it also came with this huge responsibility because at that point we didn't know if there were any others. The fires were still burning and feral cats had also survived.

"We'd get a dunnart on a camera trap and then an hour or so later we'd see a feral cat. Any surviving animals were easy for them to find. It was a pretty scary time."

With the future of an entire species hanging in the balance, stage one of a cat-proof fence was erected in record time. The initial refuge covering 12 hectares was then expanded to 380 hectares.

It's there that the dunnarts have been busily doing their thing, free from the threat of becoming a meal.

Mr Hodgens said camera traps now routinely capture dunnarts across the entire fenced area.

"They are no longer relying on this little unburnt patch of vegetation. They're moving out as the vegetation has recovered and now they don't have that threat of feral cat predation, their population does seem to be increasing."

The camera trap monitoring showed a six-fold increase in dunnart detections in August, indicating a big breeding event, with young animals dispersing and males moving over large areas looking for a mate.

Mr Hodgens is now fairly optimistic the species will survive, with dunnarts also being sighted outside the fence. But the camera traps suggest there are two to three times more individuals inside the fence than outside it.

He fears what will happen to those on the outer if cat control efforts drop off. Some programs are due to run out of funding in 2023.

"The amount of funding that was given to bushfire recovery we can't complain about, but it is becoming less of a priority ... there's a huge amount of effort that needs to go on, for years after bushfire."

The Kangaroo Island dunnart is listed as critically endangered by the International Union for Conservation of Nature, and endangered by the federal government which has pledged to ward off any new extinctions.

The predator-free fence was the work of the Australian Wildlife Conservancy, Kangaroo Island Land for Wildlife, and the Doube family who have set the Western River bushland aside for conservation.