Family room: Wolves need enemy-free space to raise offspring say ecologists

May 13, 2014 by Mary-Ann Muffoletto
In an National Science Foundation-funded study published in the ‘Journal of Animal Ecology,’ researchers provide empirical support for hypothesis that intrinsic density-dependent mechanisms might regulate territorial carnivore populations at high ungulate densities. Credit: Photo by Dan Stahler/National Park Service.

Without adequate space to raise their offspring, wolf packs lash out at competing clans and fight to the death to protect their turf.

That's among findings of a recent study by Utah State University ecologist Dan MacNulty and colleagues from the University of Oxford and the Yellowstone Wolf Project. The team published the research in the April 21, 2014, online issue of Journal of Animal Ecology. Their paper will appear in a future print edition of the British Ecological Society publication.

"Many think wolf populations are limited only by prey numbers," says MacNulty, assistant professor in USU's Department of Wildland Resources and the USU Ecology Center. "That's not the case. A vital resource for wolves is enemy-free space to safely raise pups."

Using 13 years of data collected from 280 radio-collared wolves in Yellowstone National Park, the researchers assessed the effect of wolf density, prey abundance and population structure, as well as winter severity, on age-specific survival in prey-rich and prey-poor areas of the park.

Yellowstone serves as a valuable laboratory to study the canines, MacNulty says, because the animals are not hunted there.

"It's difficult to study territorial behavior outside the park where wolves are more widely dispersed," he says. "Inside the park, we could watch fights between packs."

The team found attacks on wolves by rival packs is the number one cause of mortality – even in areas where prey is abundant.

"More wolves meant more fighting and killing," MacNulty says. "As a result, survival rates declined as wolf density increased."

The study offers valuable management information in areas where co-exist with humans and livestock.

"Although our findings suggest that high density can tolerate some human-caused mortality, we caution that the level of tolerance will depend on how such losses disrupt social structure and replace natural sources of mortality," MacNulty says.

The team's research was supported by the National Science Foundation, Yellowstone National Park and the Yellowstone Park Foundation.

Explore further: Isle Royale wolf decline boosts moose

add to favorites email to friend print save as pdf

Related Stories

Strength in numbers? For wolves, maybe not

Sep 29, 2011

(PhysOrg.com) -- Watching a pack of wolves surround and hunt down much larger prey leaves most people with the impression that social predators live in groups because group hunting improves the odds of a kill. ...

Isle Royale wolf decline boosts moose

Apr 30, 2014

A scientific report says the wolf population of Isle Royale National Park in Lake Superior is dangerously low for the third consecutive year, while moose numbers are steadily rising.

Who's afraid of the big, bad wolf? Coyotes

Sep 11, 2007

While the wily coyote reigns as top dog in much of the country, it leads a nervous existence wherever it coexists with its larger relative, the wolf, according to a new study from the Wildlife Conservation ...

Research model unlocks secrets of wolf pack behavior

Apr 02, 2014

(Phys.org) —A team of researchers with members from AEPA Euskadi in Spain and Hampshire College in Massachusetts has developed a computer model that shows that wolf pack behavior depends on the social structure ...

Recommended for you

Japan wraps up Pacific whale hunt

6 hours ago

Japan announced Tuesday that it had wrapped up a whale hunt in the Pacific, the second campaign since the UN's top court ordered Tokyo to halt a separate slaughter in the Antarctic.

Algae under threat from invasive fish

7 hours ago

Tropical fish invading temperate waters warmed as a result of climate change are overgrazing algae, posing a threat to biodiversity and some marine-based industries.

User comments : 0