Call them thieves, opportunists, bullies or just hungry meat eaters. However you label them, the presence of wolves on the same landscape not only forces their mountain lion apex predator rivals to leave meals behind but to entirely change their diets. 

New research draws on nine years of GPS data from collared wolves and mountain lions combined with field investigations of nearly 4,000 potential wolf or mountain lion kills in Yellowstone National Park. 

“When one carnivore steals a kill from another carnivore, this is a behavior that is called kleptoparasitism. So, it’s theft and it only benefits one species,” said Wes Binder, lead author of the study and Ph.D. student at Oregon State University’s College of Agricultural Sciences. “But what’s interesting about wolf and cougar interactions is that cougars are very proficient at hunting themselves. So, they don’t need to play this game of scavenging from other large carnivore kills because they can create those kill sites themselves...but wolves are very proficient at kleptoparasitism.” 

Binder said since elk numbers in Yellowstone declined over the last three decades, mountain lions shifted their focus from elk to deer.  

“Because deer are smaller, cougars eat them faster because it gives wolves less time to find a cougar sitting on its kill so kleptoparasitism is tied to the diet of cougars. If there’s no escape terrain nearby, then cougars run the risk of mortality from wolves in those places,” said Binder. 

The study builds on decades of research showing that wolves dominate interactions because they live in packs, while cougars are solitary. 

Click here to read the Oregon State news release and see a video as well as other imagery. 

About Hunt 2 Conserve 

Hunt 2 Conserve is a 501(c)4 nonprofit organization affiliated with the Rocky Mountain Elk Foundation. Its mission is to advance a legacy of hunting and conservation by educating, activating and developing stewards and defenders of these fundamentally American ideals. For more information, go to hunt2conserve.org. 

(Photo credit: Wes Binder/Justin Duffy/Oregon State University)