Gray wolf caught on camera in Denali National Park in Alaska.
Kaija Klauder/University of Washington
A gray wolf in Denali National Park and Preserve, Alaska, shown on a wildlife camera. Wolves and cougars are the top predators in most western landscapes.

In many parts of the world, there is an imbalance in the food chain.

Without top predators such as wolves and grizzly bears, smaller meat-eating animals like coyotes and foxes or grazers such as deer and elk can balloon in population, unchecked. This can initiate more deer-vehicle collisions, scavenging by urban coyotes and other unnatural human-animal interactions.

University of Washington researchers have discovered that large predators play a key yet unexpected role in keeping smaller predators and deer in check. Their “fatal attraction” theory finds that smaller predators are drawn to the kill sites of large predators by the promise of leftover scraps, but the scavengers may be killed themselves if their larger kin return for seconds.

The study, published March 18 in the journal Ecology Letters, is the first to examine carnivore killing and scavenging activities in relation to each other across dozens of landscapes around the world. Patterns that emerged from their analysis could be used to make important management decisions about large carnivores worldwide, the authors said.

“I hope this paper will spur researchers to think more holistically about these killing and scavenging interactions, because currently we’re not really getting a full understanding of how carnivore communities function by examining them separately,” said senior author Laura Prugh, a wildlife ecologist and associate professor in the UW School of Environmental and Forest Sciences.

Large carnivores such as cougars, wolves and grizzly bears have disappeared from many regions, allowing some smaller carnivores — coyotes, foxes and bobcats, for example — to increase in population. The absence of large carnivores, especially on the East Coast, also has ignited populations of deer and other prey, creating an imbalance in many areas.

Read more at UW News »