Larger Wolf Packs Less Successful in Hunting Elk

courtesy of the Salt Lake Tribune
by Brian Maffly

A few weeks ago Yellowstone National Park officials discovered the carcass of one of the park’s deadliest wolves, an aging male that scientists knew to be an aggressive bison hunter.

Wolf No. 495 died naturally, but his body bore bruises consistent with injuries inflicted in an encounter with large game, according to Dan MacNulty, an assistant professor of wildlife ecology at Utah State University.

The wounds found on No. 495 help explain MacNulty’s latest findings that wolves’ hunting success bears little correlation to the size of the hunting party beyond four wolves. Wolves hunt in groups because taking down large hoofed animals is not only challenging but dangerous.

But if the attack party exceeds four animals, the chance of success levels off, according to research MacNulty and colleagues published this week in the journal Behavioral Ecology.

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Keystone Species: How Predators Create Abundance and Stability

courtesy of Mother Earth News
by Douglas Chadwick

Long reviled as beasts of waste and desolation, wolves — along with other keystone predators — actually bring ecological stability to the habitats in which they live.

After an absence of half a century, wolves came back to Glacier during the 1980s, trotting across the border from neighboring Canadian wildlands. Suddenly, this Rocky Mountain landscape held more carcasses of deer, elk and moose, and those of us who frequented the slopes began to discover a few scavenging grizzlies later and later into the frozen season. One valley, with prime wintering grounds for hoofed herds, hosts a big male silvertip grizzly that I’m not sure ever holes up to snooze anymore.

Wolverines, with their unsurpassed nose for leftovers, can find more meals now as well. So can wintering bald eagles and golden eagles, along with northern ravens, which often follow wolf packs on the prowl. Wildlife biologists tracking the wolves discovered them taking over fresh kills made by mountain lions. In many cases, the packs seemed to be honing in on the sight of circling ravens or the birds’ excited calls in order to find the stealthy cats and drive them off their prize. Before wolves were reintroduced to Yellowstone National Park in the mid-1990s, cougars had expanded their range to include broad valley bottoms. After the wolves’ return, the cougars retreated to the steeper, more broken upland terrain they had normally hunted.

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