Prey size plays surprising role in competition among wolves, bears and cougars
New research from the University of Minnesota upends long-held understanding about how wolves, bears and cougars — three of Yellowstone National Park’s most iconic carnivores — compete for prey.
For years, scientists theorized that when prey becomes scarce, predators become more aggressive toward each other. It’s a straightforward theory: fewer resources and more competition suggest that dominant predators — like wolves and bears — will steal food from subordinate predators — like cougars.
New findings, published in Communications Biology, reveal the size of prey animals plays a surprisingly pivotal role in competition patterns among predators.
“This work really showcases the complex ways large carnivores make a living,” said lead author Jack Rabe, a graduate student in the College of Food, Agricultural and Natural Resource Sciences. “We found that shifting cougar behavior is likely a key factor in the ecosystem's stability. By opting for smaller prey, cougars reduce the amount of time they spend hunting to make up for kills lost to other carnivores. This allows them to maintain a relatively stable kill-rate, which, in turn, contributes to the overall balance of the predator-prey dynamics in the park.”
