Study Examines Role Of Coyotes In Declining Mule Deer Numbers

May 10, 2019

UW Researchers release a coyote after putting a collar on it.
Credit Melodie Edwards / Wyoming Public Radio

University of Wyoming researchers are trying to find out if predators are affecting the low population of mule deer near Rock Springs. Statewide, mule deer have declined by 31 percent since 1991. As part of the project, researchers put tracking collars on 30 coyotes and have been watching their behavior to see if their behavior changes during peak times when fawns are born. 

UW Zoology and Physiology grad student Katey Huggler said so far, they've found that, yes, the paths of coyotes do become much more complex at that time.

"So that indicates to us that coyotes are indeed changing their behavior and maybe tracking this sort of pulsed resource that's occurring on the landscape," Huggler said. "However, it doesn't necessarily suggest that coyotes are actually effective at it or having an actual effect on population dynamics as a whole."

Huggler says the research also shows that coyotes travel much longer distances than previously thought.

"Coyotes move a lot, way more than I ever would have expected," she said. "We have coyotes that move 110 miles one direction in two days and then turn around and come back and do the same thing three or four times in a row before they decide to settle down."

Huggler said, other studies have used lethal control to see how much impact coyotes have on mule deer populations, but this study is taking a different tactic.

"We're more focused on coyote behavior and really trying to understand coyote behavior on a deeper level to really get at what we can do to manage if coyotes are a problem, or maybe coyotes aren't the problem in certain years."

The study is part of the Deer-Elk Ecology Research Project, looking at why mule deer populations are sliding while elk's are growing steadily.