Study: Wolves Helping to Increase Yellowstone Grizzly Population

There's no doubt that wolves have a large impact on any habitat they are introduced into. But, oftentimes the exact effects topline predators have on the flora and fauna aren't fully understood.

A new study published in the Journal of Animal Ecology looks to shed a little more light on some of those interactions. Researchers from Oregon State University and Washington State University found that reintroduced wolf packs are actually helping Yellowstone grizzlies. By preying on elk herds, the wolves are incidentally decreasing grazing pressure on the park's berry bushes, one of the grizzlies' favorite food sources.

_"For the past century, berries have been almost absent from the diets of grizzly bears in Yellowstone, despite the fact that a variety of species grow in the area. Everything from serviceberry to huckleberry once provided bears with the nutrition they needed over the summer. Yet elk have cropped the berry bushes, consuming entire plants and leaving little for the bears to feast on as they prepare to hibernate for winter. The wolf introduction, though, changed all of that. The wolves began to cull the elk herds, scaring them away from habitat that included berry bushes. This became a boon to the grizzlies.

'Wild fruit is typically an important part of grizzly bear diet, especially in late summer when they are trying to gain weight as rapidly as possible before winter hibernation," said William Ripple, one of the researchers, in a news release. "Berries are one part of a diverse food source that aids bear survival and reproduction and at certain times of the year can be more than half their diet in many places in North America.'"_

Obviously, one study doesn't paint the whole picture of the relationship between wolves, elk, and grizzlies. For example, grizzlies also rely on elk as a main food source. If nothing else, this study does give us a little glimpse into the complex relationships between predators, prey, and habitat.