Lawsuit Raises Questions About Effectiveness Of Coyote Control Measures

May 17, 2019

In a canyon near Rock Springs, a helicopter descends, and two coyotes are handed out, bound and blindfolded. University of Wyoming researchers place them on a mat, the animals calm and still. UW Zoology and Physiology Ph.D. student Katey Huggler oversees this study.

"We collect sex, age, weight, and a few body measurements, just to get an idea how big the coyote is, those sorts of things," she says. "But what really is most important to us is that GPS data."

These coyotes will wear these collars for the rest of their lives. Around 30 coyotes are now collared and roaming these hills and, boy, do they roam. Huggler is amazed at one young female who wandered all the way to Colorado.

"It was like 110 miles as the crow flies, turned around came back three days later. Spent a month in Salt Wells and then turned around and went back again and then died down there," she says.

And they don't go the easy way, Huggler says, but straight over the steepest ridges. "They're moving fast but they're also moving really far."

But Huggler says she's curious if all that roaming changes during the window when mule deer fawns are born. Mule deer numbers around the West are declining, down by 31 percent since 1991, and some people blame coyotes.

UW Professor Kevin Monteith takes measurements and collars a coyote in hopes of tracking his behavior in mule deer country near Rock Springs.
Credit Melodie Edwards

UW wildlife professor Kevin Monteith says they're mapping coyote movement to see if the predators are targeting newborn fawns.

"They're definitely seeking out those places, which for an opportunistic carnivore like that makes a lot of sense," he says. "These deer are giving birth within a two to three-week period, it's a prey item that's highly vulnerable, protein-rich…"

It stands to reason that maybe killing off some of the coyotes would allow more fawns to survive, but Monteith says that's not what the research necessarily shows.

"Perhaps [that's] why predator control can be a really challenging thing to do sometimes because you may do your best to implement a control program in one area and the next day you just have an exchange of animals that come right back in and fill that place," says Monteith.

In fact, some studies show that if you kill off a lot of coyotes to help their prey, the coyotes breed even more, making coyotes even more of a threat.

"Oftentimes, coyote control programs have been implemented and in some or many instances the effects were negligible," says Monteith. That was even the case in a 2008 study in these same mountains where 208 coyotes were killed to see if big game numbers increased. But the results were unimpressive: pronghorn inched up a bit but mule deer stayed the same.

Yet these conclusions haven't affected the high number of coyotes killed by Wildlife Services, the little-known federal program run by the U.S. Department of Agriculture that conducts such lethal control. In 2017, the agency killed 5,645 coyotes in Wyoming, mostly to protect lambs and calves. (3,221 of those were shot from a plane, 164 poisoned with M44 cyanide, 334 trapped in a neck snare.) Montana, another sheep growing state, killed more than Wyoming: 6,165. Colorado killed significantly less: 1,811. Nationally, the agency killed 68,000 coyotes.

But some wildlife groups and researchers are wondering why coyotes and other predators are shot, trapped and poisoned when the science doesn't show it works very well.

"This is something we've been working on at a national scale, really trying to transform Wildlife Services," says Collette Adkins with the Center for Biological Diversity, a wildlife group that's filed a lawsuit against Wildlife Services in Wyoming because they say the state's environmental assessments here are outdated.

"An agency like in Wyoming which is relying on science primarily from the '70s and '80s, maybe the early '90s, that just isn't okay," says Adkins. "When it's a couple of decades old, they need to take another look."

And a lot of new information has come out about the role predators play in a healthy ecosystem.

"In this last decade, we have seen this growing body of literature that points to the effectiveness of non-lethal methods. So, for example, using guard dogs or fencing or frightening devices," says Adkins.

Such methods are primarily used to protect livestock.

Rod Merrell is with Wildlife Services in Wyoming. He says, guard dogs do work, and Wildlife Services encourages the use of them.

"I will be the first to admit that guard dogs are effective. Hands down, no doubt about it."

But he says the effects of noisemakers aren't long-lasting. As far as new data that female coyotes breed more after their killed back, he's not convinced.

"I have read those studies and from my personal experience in the field for 23 years, I don't agree with them. The number of pups a female's going to have is specific to genetics."

What Merrell is saying is that he's seen that lethally controlling coyotes does still work best to protect prey, whether livestock or big game.

"One thing I have learned in my career is that for every study out there that proves a particular point, there's another study that refutes it," says Merrell.

But more and more court judges are convinced by the latest research: California, Arizona and Idaho all are now required to change their plans to include more nonlethal approaches.

In the canyon, the research team is getting to release the two coyotes into the wild. They're both outfitted with GPS collars and Researcher Tayler LaSharr is teaching a classmate how to release them into the wild.

"When I'm ready and you say you're ready to go you'll, like, take your hands back and push him. They run really fast," she explains.

The young male coyote springs away from their hands. He looks back for a half second, confused at his freedom, and then he's gone.