Battle for the bite sized

Restoration efforts on Bon Bon Station Reserve are allowing native animal populations to recover and laying the groundwork for the return of species not currently present in the region. 

Bon Bon Station Reserve is painted from a rich palette. Bold strokes of red-soiled Bluebush shrubland, chalky-green Mulga and black-trunked Desert Oak blend northward to shimmering buckshot plains.

But while it may be rich in colour, Bon Bon – like much of arid Australia – is not as rich in species as it should be. The reserve’s small mammals, birds and reptiles have all suffered from the arrival of European Red Foxes and feral cats.

“I have seen this devastation first hand,” says Kate Taylor, Project Officer at Bon Bon.

She lists the animals she has found in the stomachs of feral cats: skinks, Knob-tailed Geckos, frogs, small snakes, native mice, rabbits, centipedes, crickets, grasshoppers and small mammals like the Kultarr.

“Anything small and bite sized is on the menu.”

One of Bush Heritage Australia’s long-term goals for Bon Bon is to reintroduce species that were once widespread across the region, such as the Bilby and Burrowing Bettong. The last of the mainland subspecies (two other subspecies persist on islands off the West Australian coast) of the Burrowing Bettong disappeared from South Australia’s deserts in the late 1950s, their extinction largely due to predation by cats and foxes.

For the past two years, Kate and her husband Clint, who manages Bon Bon Reserve, have been intensively controlling foxes and cats through hand-baiting, shooting and trapping within a ‘core’ area of the reserve.

Cats and foxes are also controlled on the reserve outside of the core area, but less intensively. The aim is not to rid the entire reserve of cats and foxes; rather, we’re trying to lower their density so that native species numbers can naturally regenerate.

Each year, a team of Bush Heritage staff and volunteers traps small mammals and reptiles at 18 sites across the reserve, half of these inside the core area and half outside. Comparing the numbers and types of animals trapped within and outside of the core area allows Kate to assess the conservation benefit of the intensive predator control program.

Over the five-day trapping period, three teams of people monitor 108 pitfall traps, which are 60 cm-deep buckets dug into and level with the ground, with a long, low mesh fence radiating out from the bucket to ‘guide’ animals into the trap. Even with three teams of people, the pitfall trapping can be challenging and tiring.

Each team must traverse the 216,808 hectare reserve (roughly the size of the ACT) twice a day; once at dawn to check the traps for nocturnal animals, and then again in the late afternoon to check for diurnal (non-nocturnal) animals.

When an animal is found, it's generally taken back to the homestead so it can be measured and the data recorded, before being returned to the capture site.

“We have three to four volunteers on each team, so we really couldn’t do these trapping events without their help,” says Kate.

“Three teams of people monitor 108 pitfall traps, which are 60 cm-deep buckets dug into and level with the ground, with a long, low mesh fence radiating out from the bucket to ‘guide’ animals into the trap.”

With the largest males weighing in at 16 grams, Giles’ Planigale is one of Australia’s smallest carnivorous marsupials. Other species of note included a Spinifex Hopping-mouse, Burton’s Legless Lizard and Painted Dragon.

Kate acknowledges that it’s early days for the predator control program and no definite conclusions can yet be drawn about the recovery trajectory of small mammals like the Kultarr. But she is optimistic that it's having a positive effect.

During the 2018 trapping period, the team captured 176 animals comprising 35 species, including the first Giles’ Planigale recorded at Bon Bon.

As she travels around the reserve, she is noticing increasing numbers of many small animals that cats and foxes are known to prey on, including juvenile Sand Goannas and Bearded Dragons, Emu chicks, and ground-dwelling birds such as quails and the rare Australian Bustard.

“Sightings like those give us hope that, yes, our control work is definitely having an impact,” she says.

This project is supported by Arid Recovery, the NESP Threatened Species Recovery Hub, the Ian Potter Foundation, the Besen Family Foundation and the Letcombe Trust.