Current News
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Wolf Control ControversiesSteve Grooms -- , 03/06/2006
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Some humans are not happy to share the ungulate prey base with wolves.
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reprint: International Wolf Fall 2003
If wolves could live on a diet of mice, humans would tolerate them better than they do. But wolves have been shaped by evolution to hunt and eat ungulates—such hooved animals as caribou, elk, deer and moose. Those are exactly the game animal species so many humans are passionate about hunting.
Some humans are not happy to share that ungulate prey base with wolves. Game populations are rarely abundant enough to please hunters, even in regions with no wolves. Where wolves are present, hunters frequently blame them for what they perceive as inadequate ungulate populations.
Disappointed hunters sometimes demand wolf control, the practice of killing wolves to enhance ungulate populations. Many state game agencies and even such thoughtful game managers as Aldo Leopold once accepted the need for wolf control to increase populations of popular ungulate species.
Wolf control is much more controversial today. In recent years Alaska has suffered from exceptionally acrimonious wolf control wars. As wolf numbers continue to increase in the Rocky Mountain region, hunters have requested wolf control to boost ungulate populations in Idaho, Montana or Wyoming. Wolf advocates will vigorously oppose such proposals.
Is it good policy to reduce wolf numbers to improve ungulate populations? That simple question, unfortunately, has no simple answer.
Critics of wolves describe them as killing machines with the ability to decimate game populations. For example, a Web site currently on the Internet compares wolves to piranhas. The site’s author claims wolves kill for “lust,” asserting that wolves will destroy “every available animal” before turning cannibalistic and devouring each other.
Wolf advocates reply that predator and prey species have evolved over the millennia to coexist. Indeed, the very nature of predator-prey relationships requires parity; if either side held a big advantage, the relationship would collapse. Vigorous ungulates can almost always escape or fight off wolves. To a remarkable degree, wolves target compromised animals—those that are sick, injured, old or very young. That leads to the comforting observation that by eliminating less fit ungulates, wolves enhance the gene pool and improve the survival chances for fit individuals.
And yet the impacts of wolf predation are not always so simple or benign.
The most-studied predator-prey relationship is on Isle Royale, where wolves and moose have coexisted without outside interference since 1949. Researchers there have learned that weather events can affect the vulnerability of moose to wolves. Fluctuations in moose numbers affect the quality of the browse, which then affects the health of the moose herd. The Isle Royale experience suggests that weather, habitat quality and predation combine in complicated ways to change wolf and moose populations.
Predator-prey relationships are even more complex everywhere else. Isle Royale moose contend with only a single predator, whereas ungulates in Alaska are eaten by wolves, black bears, brown bears and humans. Multi-predator ecological systems are difficult to study and tricky to manage.
Research in Alaska suggests that combined wolf and bear predation can limit ungulate populations to levels significantly lower than the habitat should be able to sustain. Predators sometimes suppress ungulate populations by taking high numbers of juvenile ungulates, especially moose and caribou calves. Alaska’s managers describe some imperiled ungulate populations as being caught in a “predator pit” that pins them at low levels for many years.
Wolves can even contribute to the extirpation of local ungulate populations, as was shown by a study in Minnesota’s Superior National Forest. Deer survived for many years in a region that had marginal habitat. Then a combination of wolf predation and several successive severe winters eliminated the deer. Deer have not returned to that a
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