Wolf packs dominate Yellowstone cougar populations through prey theft and targeted lethal encounters

Oregon State University study shows wolves dominate Yellowstone cougars by stealing kills and forcing them to hunt smaller prey in safer terrain.

By: AXL Media

Published: Mar 4, 2026, 9:06 AM EST

Source: The information in this article was sourced from Oregon State University

Asymmetric competition between apex predators

Researchers from Oregon State University have documented a one-sided rivalry between wolves and cougars within the borders of Yellowstone National Park. After analyzing nearly a decade of GPS tracking data and investigating thousands of kill sites, the study published in PNAS highlights that wolves frequently muscle in on carcasses claimed by cougars. While wolves were found to scavenge from cougars and occasionally kill them, there was no recorded evidence of cougars returning the favor or scavenging from wolf kills. This power imbalance stems largely from the social structure of the two species, as wolves operate in coordinated packs while cougars remain solitary hunters.

Dietary shifts and tactical adaptation

To mitigate the risks associated with wolf encounters, Yellowstone's cougars have significantly adjusted their hunting strategies. As elk numbers in the park declined, cougars shifted their focus toward deer, which rose from 15 percent to 42 percent of their diet between the late 1990s and 2024. Deer are smaller and can be consumed much faster than elk, which reduces the window of time a cougar must remain at a carcass and lowers the probability of a wolf pack arriving to steal the kill. Additionally, cougars have learned to prioritize hunting in areas with immediate access to escape terrain, such as steep cliffs or climbable trees, to ensure a quick exit if threatened.

Extensive field investigations and data collection

The research team, led by doctoral student Wesley Binder, conducted field investigations at 3,929 potential kill sites throughout the northern region of the park. By combining GPS movement patterns with machine learning models, the scientists were able to reconstruct predator interactions with high precision. Of the interactions identified at predicted kill sites, approximately 42 percent occurred where cougars had successfully hunted prey, whereas only one interaction was recorded at a site where a wolf had made a kill. This data confirms that wolves are the primary aggressors in these encounters, actively seeking out and usurping the labor of their feline competitors.