Feral instincts

From the saltbush plains of Boolcoomatta in South Australia, to the sandy dunes of Ethabuka in Queensland, Bush Heritage staff are working hard to implement science-based methods to combat feral cats.

Hidden in a shallow cave in the centre of Charles Darwin Reserve in Western Australia, there is a beautifully sculpted nest of sticks. It’s the former home of a Stick-nest Rat, a rodent last seen in this landscape decades ago. For Bush Heritage Ecologist Dr Vanessa Westcott, the nest is a reminder of the fate awaiting other native species if we don’t do more to protect them from feral animals.

“Stick-nest Rats used to occur across a huge area and you can still find their nests all over the desert,” says Dr Westcott. “Those nests are like tombstones - they’re reminders of what was, and the need to act to stop what could be.”

Other native animals such as bilbies and bettongs have also disappeared from the region since feral cats and foxes arrived, and similar stories are repeated across much of Australia.

Sobering new research suggests feral cats now cover 99.8% of the country*, and our most vulnerable species are being driven to the brink.

No-one is more aware of the threat feral cats pose to our native species than Dr Alex Kutt, Bush Heritage Ecologist for south-west Queensland. His portfolio includes Ethabuka, Cravens Peak and Pullen Pullen reserves, which together protect a multitude of native animals, including Night Parrots, Hopping Mice, and Mulgaras.

Dr Kutt says the science behind feral cat eradication and minimisation techniques must continue to evolve.

“Feral cat control into the future needs to be more creative. It must be holistic and include a range of targeted management actions across the landscape,” he says.

Bush Heritage already employs a multi-faceted approach across many of its reserves, such as on Pullen Pullen – home to the endangered Night Parrot – where electronic ‘grooming traps’ have been trialled.

The grooming traps, designed by South Australian ecologist John Read, make use of the instinctive grooming behaviour of cats and can work from up to 4m away. Placing them strategically throughout the landscape further improves their efficacy.

“We know feral cats use fire to hunt – they sit and wait for their prey as it escapes the flames. Based on that knowledge, we’re putting the traps near controlled burns where feral cats will occur in higher numbers,” says Dr Kutt.

Watch and learn

Without adequate monitoring, it’s impossible to know where feral cats are most prevalent, and thus where to focus suppression work. For this reason, a number of monitoring programs are currently in place.

On Charles Darwin Reserve, motion-sensor cameras are being used to monitor cat activity as part of the ‘Eradicat’ bait trial, as well as Malleefowl activity in baited and unbaited areas.

Dr Westcott says the aim is to see how Malleefowls, native ground-dwelling birds, respond to reductions in feral cat numbers.

“We’re not just hoping to see lower feral predator activity in the baited areas; the ultimate goal is to see increased Malleefowl activity. This will help us to be sure that our predator control efforts are effective,” says Dr Westcott.

The cameras on Charles Darwin are used to monitor both feral cat and fox numbers.

“You can’t target one without considering the other,” says Dr Westcott. “If you just target cats, you may in fact increase your fox numbers in the process, and vice versa.”

“Recently, the results of the camera monitoring have been showing we have more feral cats than foxes. We will, however, continue to monitor the activity of both species so we can alter and adapt our control efforts accordingly.”

Species under threat

On Boolcoomatta Reserve in South Australia, 60 motion-sensor cameras have been installed to determine the population and location of feral cats on the property.

The 63,000ha reserve supports species such as Bearded Dragons, Dusky Hopping-mice and Plains-wanderers. It’s a haven for native wildlife, and a potential smorgasbord for feral cats – something Boolcoomatta Reserve Manager Alistair Dermer is well aware of.

“We currently rate feral cats as a serious threat here on Boolcoomatta, and for most of Australia, and they’re contributing to species extinctions,” says Alistair. “From this data, we'll be better equipped to target our ongoing cat control.”

Save our Species

Feral animals are causing untold damage to our native species. It’s only through your generous support that we can continue to deliver a range of smart, science-driven solutions to control feral animal numbers on our reserves.

With the feral cat population reaching crisis levels, the need to implement such solutions has never been greater. Can you donate to help?

* S Legge, BP Murphy, H McGregor et al., 'Enumerating a continental-scale threat: How many feral cats are in Australia?', Biological Conservation, vol. 206, 2017, pp. 293-303.