Australian feral cat. (Beth Clifton collage)
Scheme targets only specific cats who eat endangered marsupials
ADELAIDE, Australia––Australian cat-haters rejoiced and cat advocates threw up their hands in horror after Adelaide Advertiser reporter Michelle Etheridge on November 30, 2021 revealed the latest of generations of government schemes to poison feral cats and foxes who allegedly prey upon endangered small marsupials.
Overlooked in the ongoing efforts to purge feral cats and foxes as a purported ecological treat is that the cats and foxes have also, for more than 150 years, been the primary predators of introduced mice, rats, and rabbits, all of whom Australian government agencies have also long sought to poison out of existence.
(See Will Australia learn that "When the cat is away, the mice will play?")
Even more overlooked amid the fireworks over the latest cat-and-fox poisoning plan is that it may signal a retreat from the past practice of indiscriminately distributing non-target-specific poisoned baits in vast quantities.
(Beth Clifton collage)
May show cats prey less on marsupials than conservationists think
Past practices, as well as killing many of the native Australian animals supposedly being protected, also kill cats and foxes who ignore endangered small marsupials, while protecting the marsupials from introduced competitors: specifically mice, rats, and rabbits.
The newly unveiled poisoning scheme will kill only feral cats who actively prey upon endangered small marsupials within specific protected habitats.
Cats who prowl those habitats hunting mice, rats, and rabbits will be left unharmed––at least by this poisoning scheme, though cats will likely remain targeted by other means until, and unless, the endangered marsupials accomplish a population recovery in the presence of cats.
Australian ailurophobia at that point will lose the quasi-scientific defense long shrouding some of the most aggressive yet most eminently unsuccessful efforts to kill cats undertaken anywhere since the Middle Ages.
(University of South Australia graphic)
Implants in prey species less deadly than carpet bombing poison pellets
Previewed a University of South Australia media release, hours before Etheridge of the Adelaide Advertiser spilled the lethal beans, "Using polymer chemistry principles, researchers at UniSA's Applied Chemistry and Translational Biomaterials Group have created novel Population Protecting Implants to provide a targeted method for controlling invasive and problem feral cats.
"The rice-sized implants are injected just under the skin of native animals," much like a pet identification microchip, the University of South Australia media release explained.
"They remain inert, only activating when digested by a feral predator. The result is deadly," the media release said.
Yet the outcome, a single poisoned cat or fox, will not be nearly so deadly to so many animals, including cats, foxes, birds, dingoes, and other nominally protected native species, as carpet-bombing habitat with tens of thousands of poisoned baits which may continue to kill both target and non-target animals many years after deployment.
Bilby, microchip, & Population Protecting Implant.
(Beth Clifton collage)
Bilbies
Said University of South Australia Ph.D. candidate Kyle Brewer, who developed the latest approach to poisoning cats as a 2021 recipient of an Australian Wildlife Society research grant, "Smaller, 'meal size' mammals are most at risk [from cats and foxes], especially ground-dwellers such as the bilby, bettong and quoll.
Brewer is focused on trying to recover bilbies, a rabbit-sized omnivorous burrowing species whose ecological niche, among North American mammals, might be most similar to that of the armadillo.
Wrote Etheridge, "While bilbies co-existed with aboriginal people for 60,000 years, in the 200 years since Europeans arrived in Australia they have been pushed close to extinction."
The estimated 64 to 68 million sheep in Australia probably have most to do with that, compacting soil, nibbling vegetation to the roots, and leaving the arid habitat much more vulnerable to fire than it appears to have been in prehistory.
Kyle Brewer. (Facebook photo)
"Incursive" feral cats
But cat predation has long frustrated Australian conservationists trying to re-establish bilbies and other small endangered marsupials in restored habitat.
"Efforts to remove feral cats from a native landscape have had limited success," Brewer acknowledged, no matter how many cats have been trapped, shot, or poisoned by previous methods, "making it near impossible to re-establish threatened native populations outside a fenced area. Invariably, when native mammal reintroduction schemes are activated, they are swiftly wiped out by an incursive feral cat."
Though Brewer did not specifically say so, grammar suggests that he meant just one cat here or there who happens to develop a taste for bilbies, or whatever other endangered marsupial is the subject of a restoration effort.
Many of those species, bilbies included, are somewhat larger as adults than the normal feline prey range.
(Beth Clifton collage)
"Protective buffer"
"By injecting native species with the Population Protecting Implant before they are reintroduced to their natural environment, we're providing a protective buffer that aims to take out the feral invader in one stroke," Brewer said.
"If a feral cat successfully preys upon one of the PPI-injected mammals," Brewer continued, "the cat eats the implant, which activates in the cat's gastric system, causing poison release and death. Ultimately, this protects the remaining native animal population."
And only the cat who actually kills and consumes a bilby or whatever is harmed.
Continued the University of South Australia media release, "The Population Protecting Implants are covered by a protective coating and contain a toxin derived from a natural poison in native plants. They present no danger to tolerant native mammals, but are deadly once the toxin is activated in the introduced predator's stomach."
Tiger quoll. (Beth Clifton collage)
30 bilbies implanted
The Population Protecting Implant project is still in a trial phase. Three entities besides the University of South Australia are involved: Ecological Horizons, Peacock Biosciences, and the University of Adelaide.
Among them, they have so far released 30 bilbies outfitted with Population Protecting Implants at Arid Recovery, a 76-square-mile wildlife reserve near Roxby Downs, South Australia.
"If the trial is successful," suggested Etheridge, "the technology could be used in other areas, to help protect other vulnerable species such as bettongs and quolls.
"The idea was first raised about 25 years ago," Etheridge reported, "but this is believed to be the first time the implants have been put into practice in Australia."
(Beth Clifton collage)
No cats dead yet
University of Adelaide student Ned Ryan-Scholefield, participating in the field trial, told Etheridge, she wrote, that so far "No cats have died from killing bilbies and ingesting the implant," an indication that either feral cats are far fewer at Arid Recovery than supposed, or less inclined to hunt bilbies, or both.
"But he said," Etheridge added, that "the project began around the same time as a boom in populations of other small animals, such as hopping mice, which were easy prey for feral cats."
Hopping mice, arriving in Australia an estimated five million years ago, are among the few non-marsupial mammals that are legally identified as "native" there. The International Union for the Conservation of Nature considers hopping mice to be a "species of least concern."
(Beth Clifton collage)
"We have responded immediately"
"We have responded immediately," Cats Assistance To Sterilize committee member Lisa Roberts Daintree emailed to ANIMALS 24-7 soon after the Adelaide Advertiser published the Etheridge report on the Population Protecting Implants project.
Cats Assistance To Sterilize, Roberts Daintree explained, has "for nearly 40 years assisted the Adelaide community with low cost desexing and have desexed more than 130,000 cats.
"We are a member organization of the Animal Justice Party, Roberts-Daintree said, "with three elected members in our Eastern States. I am an outpost for C.A.T.S. and do not live on location in Adelaide, but rather in northern New South Wales," Roberts-Daintree added.
Western swamp tortoise. (Perth Zoo photo)
"Hard shell delivery vehicle"
Roberts-Daintree helps to lead opposition to the deployment of Eradicat, a poison bait using sodium fluoroacetate, better known as Compound 1080, and Curiosity, a similar poison bait using para-aminopropiophenone, nicknamed PAPP.
Both Eradicat and Curiosity were developed with Australia government support as part of a failed scheme to kill two million feral cats by 2020, announced in 2015 by former Australian environment minister Greg Hunt. Hunt recently announced his retirement from politics after a stint as health minister.
Both Eradicat and Curiosity use a "hard shell delivery vehicle" similar to the poison capsules used for Population Protecting Implants.
In a 2016 article entitled "Cat baiting using Eradicat and Curiosity: is it working?" the journal Terrestrial Ecosystems explained that, "When feeding, cats generally shear their food into manageable chunks and swallow these portions whole.
"In contrast, most non-target species typically process food items more thoroughly in the mouth. This makes the 'hard shell delivery vehicle' delivery method very effective, as non-target species usually reject the pellet.
(Beth Clifton collage)
"Bycatch can be significant"
"The Department of Parks and Wildlife has undertaken a field trial to compare the efficacy of both baits," the Terrestrial Ecosystems article continued.
Aircraft dropped 60,000 Eradicat baits and 12,950 Curiosity baits, but "An analysis of site occupancy data showed that there was no significant reduction in the feral cat population after baiting. Corvids [members of the crow family] and dingoes were photographed removing and consuming baits from a limited number of sites. However, as these individuals were not marked or otherwise identifiable, it was not possible to monitor their fate throughout the study."
Acknowledged the Terrestrial Ecosystems article, "The bycatch kill resulting from these widespread aerial baiting programs can be significant," citing a 2014 study which "reported 99% of the monitored [Compound] 1080 baits laid in the Jarrah forest of southwest Western Australia were taken by non-target species and the threatened quokka took 48% of them."
Australian politician Greg Hunt declares war on feral cats.
(Merritt Clifton collage)
"Conservation or politics?"
Biologists Tim S. Doherty and Euan G. Ritchie, cited by Terrestrial Ecosystems as critics of the Eradicat and Curiosity poisoning campaigns for a combination of ethical and practical reasons, in February 2019 joined with fellow biologists Don A. Driscoll, Dale G. Nimmo, and Ricky‐John Spencer as co-authors of an influential critique entitled "Conservation or politics? Australia's target to kill 2 million cats."
"Conservation or politics" was published by the journal Conservation Letters, the periodical of the Society for Conservation Biology.
"We argue that the well‐publicized [government] target to cull two million feral cats has a weak scientific basis," the five scientists began, concluding that, "The cull target fails to meet what would be considered best practice for pest management," and that "The focus on killing cats runs the risk of distracting attention away from other threats to biodiversity, most prominent of which is widespread, ongoing habitat loss."
(See How killing cats helped to keep Aussie Liberal Party in power.)
(Beth Clifton photo)
Compound 1080 collars
The advent of the Population Protecting Implant could mean the beginning of the end for widespread deployment of Eradicat and Curiosity, in favor of a much more narrowly focused approach that kills only those cats who demonstrably prey upon specific endangered species in specific protected locations.
USDA Wildlife Services has for nearly 40 years used an approach similar to the proposed use of the Population Protecting Implant to kill coyotes who prey upon sheep and goats, while leaving coyotes who do not mostly unharmed.
The USDA Wildlife Services method consists of outfitting some sheep or goats in herds suffering coyote predation with collars containing Compound 1080.
Since coyotes typically kill a sheep or goat with a neck bite, they have a good chance of poisoning themselves if they attack a collared animal.
Though used in at least nine states, the Compound 1080 collars have over the past 40 years killed barely two dozen coyotes per year, in contrast to the 62,500 coyotes killed by USDA Wildlife Services in 2020 using other methods.
(Beth Clifton photo)
Nixon banned Compound 1080; Reagan brought it back
Ideally no one would be poisoning any animals, including coyotes, and no one would be using Compound 1080 at all, which causes a slow convulsive death and was considered so inhumane that former U.S. President Richard Nixon banned it in 1972.
The National Wool Growers Association prevailed upon former U.S. President Ronald Reagan to rescind the ban on Compound 1080 collars and an indiscriminate poisoning device called the "coyote getter" in 1983.
Currently USDA Wildlife Services credits use of Compound 1080 collars as a factor in reducing the agency's annual toll on coyotes by about a third, from 97,953 in 1992.
(Beth & Merritt Clifton)
That in turn was much less than the average of about 250,000 coyotes per year killed by the predecessor agency, called Animal Damage Control, from the mid-1950s until all use of Compound 1080 was halted in 1972 for the next 11 years.
Most non-USDA and non-agribusiness observers credit the reduction in coyote-killing chiefly to increased public appreciation of the positive ecological contributions made by coyotes.
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