Jaguars have been trained to dislike the taste of cattle, sheep and dogs by feeding them tainted meat, suggesting a way to spare the lives of both domestic animals and the predators that prey on them.
An endangered species, jaguars roam freely under wildlife protection laws in Mexico and parts of Central and South America. But their attacks on livestock and pets have led to illegal shootings by angry owners.
By treating meat with high doses of deworming medication and wrapping it in the skin of domestic animals, scientists may have successfully thwarted attacks on livestock and pets â and hence lethal repercussions on the wild cats, says at Primero Conservation in Mexico City.
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In 1974, researchers reported trying to by taking advantage of the âfood poisoningâ effect that occurs in people when we experience nausea and abdominal pains after a bad meal and then find the same food disgusting later. This reaction, called conditioned taste aversion, evolved in most animals as a way to avoid toxic food, says Cassaigne. Unfortunately, early taste-aversion studies in wild predators generally failed because the animals could smell the poison in the meat, she says.
In 2009, Â at Primero Conservation in Pinetop, Arizona, found that thiabendazole â an odourless, tasteless deworming medication â gave two captive pumas a safe but serious stomach ache when injected into the skin-wrapped meat of desert bighorn sheep. The cats later refused to eat any desert bighorn sheep meat, he says.
Hoping to put jaguars off hunting domestic animals, Cassaigne, Thompson and their colleagues recently added high but non-lethal doses of powdered thiabendazole into 2 kilograms of mutton or pork wrapped in the animalsâ own skin. They fed this meat to six captive jaguars in three Mexican wildlife refuges.
Within 3 hours, the cats became lethargic and sometimes howled, says Cassaigne. Some later vomited and had diarrhoea for a few hours.
The next day, the jaguars had good appetites and eagerly ate beef. But none of them ate the pork or mutton offered to them. â[One female] grabbed it and had it in her mouth, but then she spit it away,â says Cassaigne. âShe was like, âOh wow, yeah, I remember now!ââ Their aversion to those specific meats lasted at least a month, when the experiment ended.
Later, Cassaigne and her colleagues injected thiabendazole into the carcasses of a calf and a feral dog that had been killed and then left by two wild jaguars in Mexico. Villagers were contemplating targeting the cats due to their killing sprees. âWe spoke with the locals and said, âPlease just let us try this instead of killing them,ââ she says.
In both cases, the wild males came back to continue eating the spoils. One never attacked another calf over the next seven months. The other killed one dog â but didnât eat it â and never attacked again over the following year of monitoring, says Cassaigne. This jaguar might have been attacking dogs for years already and was used to hunting them, making it harder to stop the habit, she adds.
at the University of CĂłrdoba in Spain says he is relieved that researchers are finally exploring the use of conditioned taste aversion in endangered felines due to their conflicts with humans over livestock. While the tests in the wild were inconclusive, those in captive jaguars showed great promise, he says.
âIt is crucial to conduct further field experiments in a more controlled manner, focusing on areas with recurring attacks that allow for before-and-after treatment comparisons,â says Tobajas. An important next step would be to follow tagged jaguars with GPS transmitters to better understand their reaction to treatment, he adds.
Training predators to learn a taste aversion before releasing them into the wild â such as in rewilding programmes â is the ideal scenario, says Cassaigne. âYou donât want to start with a problem.â
Applied Animal Behaviour Science
