Scientists to make native animals toxic to feral cats
A NEW TECHNOLOGY IS providing hope in the fight against feral cats – by implanting a poison-filled capsule into native animals, making them toxic to consume.
The implant will sit under the skin of native animals, without causing them harm, much like a microchip. The technology is being developed and tested by conservation biologist Dr David Peacock and University of South Australia polymer chemist Dr Anton Blencowe, with the help of students and colleagues.
“At pH7, under the skin, it will just sit there and won’t degrade, and hopefully the animals live long and happy lives,” David explained. “But once it reaches the more acidic gastric environment, it releases its contents, which will most likely be 1080 poison.”
“We don’t want our animals to die, but if they do, we want to take out the predator too.”
The implant will work on both cats and foxes, but David – who was previously a park ranger – says cat predation is one of the biggest issues in reintroduction programs of native animals.
Feral cats are a major threat to Australia’s native animals, such as our endangered numbats. (Image: Martin Pot/Wikimedia/CC-BY-3.0)
“Everyone knows about the problem but we have very few tools in our cat control toolbox,” he said. “And large cats can cause ‘catastrophic predation’ – found to kill multiple animals – and can just come in and destroy your whole program.”
“It’s not a silver bullet, but it’s a tool we hope we’ll be able to use with other tools. Even if we reduce predation by 10 per cent, it would make a big difference,” David added.
Toxic plants a saving grace?
It comes after David undertook his PhD in the ecology south-west WA, investigating why multiple native species – including the numbat – persisted in the south-west corner of the country, while they had disappeared elsewhere.
David said multiple accounts suggested the region’s native fauna could become toxic as a result of foraging on toxic Gastrolobium plants, reportedly causing the deaths of household cats and dogs which preyed on them or were fed their remains.
Commonly known as 1080, Gastrolobium poison is found in a number of native pea species, mostly concentrated in the state’s south west, and is currently used widely in fox and cat baits.
The compound is ideal for baiting, as native animals have developed a tolerance to the poison, while introduced predators such as cats and foxes are susceptible to its high toxicity.
“But cats are picky eaters,” David pointed out, adding, “you can put out baits in an area that could kill them, but they often choose not to eat them.”
Gastrolobium bilobum, the most toxic of 1080 bushes. (Image: MurielBendel/Wikimedia)
And that’s where the implant comes into play, which can be used in native animals all over Australia. “I specialise in using biomaterials for medical applications, so it’s really exciting to branch out into a new area,” said Anton.
“The polymer is similar to what we use for taking cod liver oil, which tastes really foul,” he explained. “You used to have to drink it, but now you get it in a polymer-coated capsule so you don’t taste it, and the oil is only released when it is in your stomach.”
Initially a labour-intensive process, Anton and his students were only able to hand-make three capsules a day, but with funding from FAME (Foundation for Australia’s Most Endangered Species) they have purchased a machine to speed up and uniform the process.
“Now we’re looking to upscale that and produce tens, maybe even thousands,” Anton says. “We’re really eager to get it out there and start saving animals.”
Trialling the toxin
The implant is yet to be used, with a crowd-funding campaign aiming to raise $30,000 to start larger-scale production and field trials to determine its effectiveness and safety.
They will most likely be packaged in a small sterile syringe, which can be taken out in the field and implanted with ease during routine monitoring of native species.
And although in its early stages, a number of people and agencies have already expressed interest in the product for a range of reintroduction programs throughout Australia.
“It is exciting, all of us in this field, we wear our hearts on our sleeves and love animals, and try to make the world a better place by the time we leave it,” David said.
“And I hope this helps us to get more native animals out in the bush in reintroduction programs.”
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