Since 2002, all but one of the 13 mountain lions tested by the National Park Service have had one or more rat poison compound in their systems — which is causing biologists to pin responsibility for a number of illnesses and deaths on unintentional poisoning.
“Various pest control companies argue that the products they use are safe and that there’s not going to be any secondary poisoning,” Riley said. “But there is. We have seen a huge amount of exposure in bobcats, coyotes and mountain lions.”
The type of poisons that have continuously been found, Riley said, are called anticoagulants. Once ingested by a rodent, these substances remove the blood’s clotting ability, and, slowly, the rat or squirrel will bleed to death internally. In some cases, the poisoned rodent can live up to 10 days after initially being exposed to the poison — leaving time for larger predators, like raccoons or foxes, to become poisoned themselves from hunting the rodents.