Coyote that was part of study died with rat poison in system

A coyote that was being studied by scientists and whose remains were discovered last month in MacArthur Park appears to have died as a result of drowning, according to necropsy results released this week by the National Park Service.

The lab results also found significant levels of four anticoagulant rodenticides in her body. Such rodenticides are known to travel up the food chain and accumulate in top predators, causing internal bleeding. 

“She had fairly high levels of anticoagulant poisoning, or rat poisons, as well, so there’s multiple factors potentially going on, but her ultimate cause of death was drowning, and it looks like she got stuck in the lake at MacArthur Park,” said Justin Brown, a wildlife ecologist with the National Park Service. 

It's unknown why coyote C-146 ended up in the lake at MacArthur Park, but Brown said once she was in, it would've been difficult for her to exit because sheer concrete walls surround the water.

He said the rodent poisons found in her body may have played a role in her choosing to enter the water, because anticoagulant poisons are known to cause thirst in animals. 

"She might have been trying to get a drink, and it’s such a deep, deep, long reach that she could’ve fallen in," Brown said.

He said it's also possible she was hunting one of the waterfowl known to reside in the lake. 

The coyote was the third that Brown had collared in highly urbanized areas of Los Angeles. Of the three, her collar was the only one still active. The other two animals are believed to be alive still, though their collars have stopped transmitting data. 

Even in death, C-146 was able to increase scientists' understanding of how coyotes exist in such close proximity to humans and development. The California Department of Pesticide Regulation has banned consumer sales of three of the anticoagulant rodenticides found within C-146, though licensed exterminators are still able to use them. Brown said the levels of chemicals found within her indicate they are still readily found within urban environments.

“All four of these were at detectable levels, which means she has been exposed at a fairly regular basis, or at least in large clumps at one time,” he said.

The coyote's remains were initially reported by students from a nearby charter high school. Jessica Herceg, a science teacher at Soledad Enrichment Actions, said students were having class in the park on the morning of December 4, when they found the coyote lying next to the lake. Herceg said an 11th grade student identified the animal as a coyote and recognized its significance. 

“She came to me at school and said, ‘That’s a coyote. It has a tracking collar on its neck,’” Herceg said. 

Though the loss of the coyote is a blow to the study, it's fortunate for Brown that he was able to recover the collar, which he plans to put on another animal in the future. Herceg said park employees nearly discarded the animal.

“They were going to put it in a dumpster,” she said.