"We reached the old wolf in time to watch a fierce green fire dying in her eyes. I realized then, and have known ever since, that there was something new to me in those eyes- something known to her and the mountain… I thought that because fewer wolves meant more deer, that no wolves would mean a hunter's paradise. But after seeing the green fire die, I sensed that neither wolf nor mountain agreed with such a view.

Since then I have lived to see state after state extirpate its wolves … I have seen every edible bush and seedling browsed…and, the starved bones of the hoped for deer herd.
I now suspect that just as a deer lives in mortal fear of its wolves, so does the mountain live in mortal fear of its deer."   

Aldo Leopold, Sand County Almanac 1949

" Relentless pursuit and destruction of the savage-tempered, strong-jawed, fur-bearing animals is in part the salvation of wildlife of to-day and yesterday."

William Hornady, Our Vanishing Wild Life 1913

  Hornady was one of the staunchest supporters of predator control. He viewed predators as direct competitors of hunters. His writings greatly influenced early public policy regarding predators in the United States.

  With the advent of the environmental movement the concept "balance-of-nature" gained a large following. Some "balance-of-nature" advocates even espoused the idea that wolves mainly fed on mice, therefore posed no threat to big game animals. This idea was largely fueled by the fictional book and movie "Never Cry Wolf." They were about a fictional biologist who was hired to determine why caribou herds were declining. Interwoven between scenes that showed him trying to communicate with wolves, eating mice, and running with caribou herds was the message that wolves weren't responsible for the declines.

  Unfortunately, few studies have focused directly on the interactions between mule deer and wolves in the West. But, we have gained some insights from studies completed in Minnesota and Alaska about how wolves may interact with mule deer.

Wolves and Whitetails
   Long-term studies in Minnesota have provided some information on the effects of wolves on prey. In these studies, white-tailed deer were the major prey. Wolf predation on deer increased during severe winters when browse and cover became limited. The deer that survived learned to occupy the gaps between wolf territories.

  When deer populations were depressed, wolves would trespass into the gaps and territories of other packs. The trespassers when encountered were attacked and sometimes killed. This reduced wolf populations, but not to low enough levels to jump-start deer populations. Wolves also were reported to have literally killed off deer populations in parts of the Superior National Forest.

Wolves and Black-tailed deer
   Observations from islands in southeastern Alaska provide cases studies regarding wolf and deer interactions. Some of these islands were inhabited wolves; others were not. Between 1952-56, deer populations one wolf-free islands appeared to be stable or slowly increasing. Biologists believed the population increases where causing severe range deterioration. As a result these populations were experiencing high winter mortality.

  In contrast, islands that supported both deer and wolves were characterized by rapidly increasing deer populations, lower winter mortality, and better winter range condition. In general, wolf-populated ranges supported a greater annual hunter harvest than wolf-free islands.

  These observations lend support to the balance-of-nature concept. However, a decade later a different picture began to emerge. Prior to 1968, deer herds were at unprecedented high levels after four years of mild winter. The winter of 1968-69 was one of the worst on record. Over 60 percent of the deer herd died. A succession of mild winters on the wolf-free islands resulted in a rapid recovery of the deer population. But, on the islands occupied by wolves, deer still continue to be scarce. These observations suggests that wolf predation on deer can be a serious limiting factor under certain conditions.

An experiment
   In 1960 biologists deliberately released four captive timber wolves on Coronation Island,
Alaska. At the time of this release the deer population was considered to be low, but stable. However, the herd had almost completely destroyed the forest understory.

  Within five years the wolf population had tripled and deer remains in wolf scat increased to 95 percent. Deer sightings also dropped dramatically and the vegetation began to recover. The wolf population increased to 15 pairs and than declined until only one animal remained. By 1975 the island was wolf-free and the deer were repopulating the island.

Some thoughts to consider
 1. Predators, wolves included, can kill a substantial number of mule deer. But, only after careful study will we know the magnitude.

 2. Several case studies suggest that wolves can decimate local deer herds. Most of these incidences occurred on islands where deer movements were restricted and other prey species were not available. When the primary prey species disappeared wolves killed each other. Given a larger area to disperse in and the presence of buffer species (elk and other big game) the outcome may be different.

 3. Mule deer numbers in the case studies reviewed were ultimately limited by the quality and quantity of habitat. Poor habitat conditions combined with hard winter weather were responsible for the initial dramatic deer herd population declines. Wolves suppressed the recovery of deer populations.

 4. The bottomline - without suitable habitat, wolves or no wolves, mule deer populations will decline.

- T. Messmer

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