Return of the Yellowstone Wolves

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That prowess is badly needed at Yellowstone. The absence of what biologists euphemistically refer to as the wolfs "evolutionary pressure" has caused a serious ecological imbalance in the park. With only a few coyotes and the occasional grizzly to worry about, inflated ungulate herds are overgrazing and destroying the range.

Studies in the wild suggest that wolf predation won't jeopardize and may actually benefit the herds as well as the grasses. For example, on Isle Royale, wolves are responsible for only 6% of ungulate deaths, mostly the unfit, calves and the elderly. When wolves were removed from nine areas in the USSR, the same number of moose still died, but from disease instead of predation. "At first we'd expect a big spurt in the wolf population," said Bishop. "Then the increase in predation will make prey less accessible, and the wolf numbers will fall. In the wild, many starve to death."

Aside from the ungulates and some coyotes, other Yellowstone species will probably not be affected by the wolves, at least not adversely. Grizzlies, too slow to get elk on their own, will find extra protein from scavenging wolf kills, according to Bishop. From time to time, even unlikely species could benefit from predation. "In 1980 and 1981 we lost many bighorn to pinkeye; the sheep couldn't see where they were going and fell to their deaths," he said. "Normally, bighorn escape wolves by retreating to inaccessible places. During the pinkeye situation, wolves might have nipped the epidemic in the bud when the first few sheep began stumbling."

Bishop's positive attitude about wolf predation is in keeping with Yellowstone's mandate to maintain its ecosystem in as natural a state as possible. But these days, biologists maintain that "natural" doesn't mean that hunter and hunted automatically preserve stable population levels if left to their own devices. On Isle Royale, for example, the wolf numbers have vacillated from 20 to 50, back down to 14, and up to 20 again.

"Weather, social stresses and territory—each pack needs a minimum of 50 square miles—as well as the availability of food combine to control wolf numbers in complicated ways," said Bishop. "A bad winter, which makes it hard for elk to forage and to escape predators, means wolves get more elk. Initially, the wolves increase, and the elk decrease. But in time, that will rebound to the wolves' disadvantage."

Our next stop was an outcropping above the park's vast winter elk range. With the aid of binoculars, brown pinpoints on the golden expanse turned into elk, some three miles away. "They're grazing in an area badly burned in the summer of 1988," said Bishop. "About a third of the range was affected, but the grasses in those parts now have three times more protein than old growth."

Vantage points like this one, high over open game territory, will be the visitor's best bet for getting a glimpse of a Yellowstone wolf. The species has evolved to take extreme measures to avoid attracting the attention of man. In parts of Europe, especially Italy, people unknowingly live near wolves all the time; if a wolf is caught by dawn light while scavenging in a dump, it just hides under a bush until it's safe to emerge. In fact, the record of confrontations, especially violent ones, between man and wolf has been remarkably one-sided. Many dogs attack people each year (in a recent year there were 11 fatalities), but there's never been a single report of an attack by a nonrabid wolf in the U.S.

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