Robotic killers that detect feral cats, spray their fur with poison and rely on them to essentially lick themselves to death have been deployed in the Australian desert for the first time.



Feral cats are one of the biggest threats to many of Australia’s endangered species, killing millions of animals every day throughout the country – and controlling them has proved difficult.

It took John Read, an ecologist seven years to invent and produce four of the “grooming traps”. After extensive testing, he has switched on the first one in a nature reserve in south-west Queensland.

“Cats are hard-wired to hunt,” Read said. That means they can kill dozens of animals a night but it also means they are often reluctant to eat baits since they prefer to kill an animal themselves.

“This trap targets the cats’ achilles heel,” Read said. Being fastidious groomers, cats will lick off almost anything that gets on their fur. So Read has developed a trap that exploits their tendency to try to get their numbers under control.

With four laser rangefinders, the trap detects when something moves in front of it. If it’s taller than a cat – perhaps a dingo or a koala – the top rangefinder will be triggered and it shuts down. Similarly, a rangefinder at the bottom needs to be able to see between the cat’s legs, meaning a low-slung animal like a wombat or a quoll won’t trigger it.

Finally, two rangefinders at the front and back of the trap need to be triggered simultaneously, indicating something the length of a cat has moved in front of it.

Read said there were two other ways the trap would avoid hurting native animals. Firstly, the poison being used was 1080, which occurred naturally in some Australian plants, and, as a result, native animals were less susceptible to it. The dose used was, therefore, able to kill three cats but unlikely to kill a native animal, he said.

The trap also relied on the animal licking the poison off its fur, which cats would reliably do, but most other animals were less likely to.

The traps were also equipped with speakers and recordings of animals that cats might prey on, including the sound of rats and cats in distress, which could attract cats to the area.

After conducting trials in enclosed spaces and a small field trial of an earlier model, Read installed the the new optimised grooming trap in “camera-only” mode earlier in the year. That allowed him to test what animals would activate the trap without actually firing any poison.

Last week the first live grooming trap was switched on in Pullen Pullen reserve, a 56,000ha property in a secret location. It was bought by Bush Heritage Australia to protect the enigmatic night parrot, a nocturnal parrot from central Australia that many thought was extinct until the 1990s.

Read was also beginning to switch on live grooming traps in Venus Bay and Wilpena in South Australia.

“The three trial locations are all part of the same trial to test and optimise the traps before we will hopefully redesign and manufacture 50 or more traps for a bigger trial at a wider range of sites,” he said.

Read said more than $450,000 had been spent developing the traps, with funding from several sources, including Bush Heritage Australia and the South Australian government.

Rob Murphy, north Australia manager from Bush Heritage Australia, said the traps were a key component of the new Pullen Pullen night parrot reserve.

“Sanctuary at Pullen Pullen reserve is critical for this special bird that still could be lost forever if we don’t work together for the long term to protect it,” he said.



• Guardian Australia travelled to Pullen Pullen reserve as a guest of Bush Heritage Australia