How Yellowstone National Park’s Grizzlies and Wolves Compete for Food

by Megan Molseed
(Photo by: Avalon/Universal Images Group via Getty Images)

Yellowstone National Park’s wolves and grizzlies are rivals as the two carnivores compete for food in one of the world’s greatest national parks. This competition makes sense. Both the wolves and grizzlies are looking to find their best sources of food. And, most times, these sources are the same for both animals. However, it seems as if the grizzlies are coming out on top, for the most part.

Does Greater Grizzly Bear Competition Lead To Reduced Wolf Kill-Rates?

As Yellowstone’s grizzly bears and wolves co-exist within the national park, it seems the competition over fresh meat often has some unexpected results. The Yellowstone grizzlies are relying on the kills of the area’s wolves to supplement their own meals. However, when the bears steal meat from the wolf-packs, the wolves begin to kill less often.

According to some recent studies on the wolf and grizzly population hunting habits within Yellowstone National Park, the grizzly bears tend to lean on wolves pretty heavily to help supplement their meals. So heavily, in fact, that it is changing the wolve’s overall pack and hunting behaviors.

Wolves Put Extra Food On the “Landscape” For Bears – However, These Grizzlies Don’t Offer the Same Help To the Wolves

As the spring-like weather continues to progress – and the actual season just around the corner – the grizzly and wolf populations are ready to hunt. The elk herds are birthing at impressive rates…giving cruising predators ample opportunity for fresh protein.

“Wolves put extra food on the landscape for bears,” notes Norwegian Institute for Nature Research scientist Aimee Tallian. Tallian works as a collaborator with a University of Montana researcher Matthew Metz; one of the researchers conducting a study on these habits of the Yellowstone wolves and grizzlies.

“But bears are antagonistic for wolves,” Tallian continues.

They take part of the supply of shared prey, and they usurp wolf kills,” the scientist adds.

“So wolves are kind of helping bears, but bears aren’t necessarily helping wolves a lot.”

“What we did was break down the wolf foraging sequence,” notes Metz.

“We studied their searching time and their handling time,” the researcher continues. “The amount of time they spend eating and digesting their kills.”

A Complex Eco-System, And A ‘Dynamic Intermplay’ Between Competitors

According to Metz, little had been known about this dynamic between the grizzlies and the behaviors of the wolves before the studies. Additionally, the experts note, this new information helps to fill in any gaps that scientists may have had regarding how this particular ecosystem operates.

“Relatively little had been known about how bears affected the foraging dynamics of wolves,” Metz explains.

“Our work starts to fill in the gap by demonstrating that the dynamics do differ,” the expert continues. “And provides another reminder of how changes in ecosystem complexity – in this case, the presence of bears – affects the behavior of other species.”

“One cool way to think about this is the historical context,” Tallian notes.

“This is likely what these systems looked like for thousands of years with this dynamic interplay of competitors on the landscape,” the scientist continues.

“There are very few places that feel that untouched these days,” Tallian adds. “Where ecosystems are allowed to play out on their own.”