The Big Story Blog

8 questions and answers about the gray wolf

Posted at 9:58 AM on December 21, 2011 by Paul Tosto
Filed under: Environment

Here's a list of Frequently Asked Questions and answers on the gray wolf written and posted by the U.S. Fish & Wildlife Service.


1) Why was the gray wolf listed as endangered?

Wolves became nearly extinct in the conterminous 48 states in the early part of the 20th century. Predator-control programs targeted wolves, and wolf habitat was altered and destroyed as eastern forests were logged and then converted to farms. Woodland caribou, bison, and beaver, the wolves' prey base, were also brought to near-extinction by settlers and market hunters. Predator-control programs, loss of habitat, and loss of prey resulted in the elimination of wolves throughout most of the conterminous U.S. except in northeastern Minnesota and Isle Royale, Michigan. A few individuals also remained in the northern Rocky Mountains.

2) What types of habitat do wolves use?
Gray wolves use so many different habitat types that they are equally at home in the deserts of Israel, the deciduous forests of Wisconsin, and the frozen arctic of Siberia. Within North America, gray wolves formerly ranged from coast to coast with the exception of the mid-Atlantic states, the Southeast, and perhaps parts of California. They were found in almost all habitat types; prairie, forest, mountains, and wetlands. In the conterminous 48 states today, they are found in the mostly forested lands of Minnesota, Wisconsin, Michigan, Montana, Idaho and Wyoming.

Wolves can live almost anywhere if they have abundant wild prey and excessive numbers are not taken by humans. The best habitat for wolves in the West is on public lands where both these needs are met. Wolf range has expanded in Minnesota and Wisconsin to include areas that are a mix of forest and agriculture. The Mexican gray wolf has been reintroduced into the mountains of the Apache National Forest in Arizona and translocated into the Gila National Forest in New Mexico.

3) Do wolves need wilderness areas to survive? Can they survive near urban areas?
It was thought that gray wolves were a wilderness species, but wolf range has expanded into areas that we once thought could not support them. In Minnesota and Wisconsin, wolves have shown that they can tolerate more human disturbance than we previously thought. Consequently, it appears that wolves can survive anywhere there is sufficient food and human tolerance to allow their existence.

From a biological standpoint, we know that wolves can and do survive near urban areas. But whether wolves survive near cities and towns will depend on people. There are areas near large cities that have sufficient wild prey to support wolves. Wolves are predators, however, and conflicts arise when they kill livestock and domestic animals, including pets. These conflicts, along with urban hazards such as vehicle traffic, will likely limit the establishment of wolf populations near urban areas.

4) How far do wolves travel?

Wolf packs usually hunt within a specific territory. It is not uncommon for territories to be as large as 50 square miles but they may even extend up to 1,000 square miles in areas where prey is scarce. Wolves often cover large areas to hunt, traveling as far as 30 miles a day. Although they trot along at 5 m.p.h., wolves can attain speeds as high as 40 m.p.h. Most wolves disperse from the pack they were born into by age three. Dispersing wolves have traveled as far as 600 miles.

5) What do wolves eat?
In the Midwest, wolves eat mainly white-tailed deer but they also eat moose, beaver, and snowshoe hare. In the Rocky Mountains, wolves feed on elk, deer, moose, bison, and beaver. Wolves even eat some insects, small mammals, nuts, and berries. They may not eat for a week or more but are capable of eating 20 pounds of meat in a single meal.

6) If wolf numbers get too high, will deer and elk be eliminated?
Wolves have lived with their prey for many thousands of years, and the health of wolf populations is dependent on the health of their prey base. Under certain conditions wolves can cause local decreases in prey numbers. But if deer and elk numbers were to decline over an extended period of time, due to severe winter conditions or habitat changes, wolves would have less food available and their health would decline. They would then produce fewer pups and fewer pups would survive to adulthood. Also, more adult wolves would die because of poor health or in conflicts with other wolves. Thus, wolf numbers would decline before their prey could be eliminated.

Isle Royale, Michigan, serves as a living laboratory to illustrate this point. One female gray wolf naturally emigrated to this island (about 132,000 acres) more than 50 years ago and eventually three packs were established. Their primary prey is moose. Through the years the numbers of moose and wolves have fluctuated, but after 50 years a moose population continues to survive on Isle Royale.

7) Do wolves really take the old, young, sick, starving, or injured animals?
It is well-documented that wolves tend to do this. Hunting and bringing down big game is dangerous work and wolves are sometimes killed by elk, moose, and even deer. In the wild, they cannot afford to be injured; therefore, they go after the safest animals to kill and often leave strong animals alone. A recent study of wolf predation on elk in Yellowstone National Park, for example, found that wolves tend to kill calves and older animals - adult elk killed by wolves were about 7 years older than elk killed by hunters. If weather or other conditions make prey unusually vulnerable, wolves can and do kill prime-aged animals but wolf predation tends to be selective.

8) How do wolves in an area affect deer hunting?
Wolves survive by preying primarily on the most vulnerable individuals in the deer population (the very young, old, sick, injured, or nutritionally compromised) thus under certain conditions their impacts on the deer population are most likely compensatory rather than additive. That is, many of the deer that wolves kill likely would have died from other causes such as starvation or disease.

However, when weather events occur, such as deep snowfalls or drought, wolves can be a factor that reduces deer numbers further. For example, since wolves became protected in northern Minnesota in 1978, there has been a high and even increasing harvest of deer by hunters. But two consecutive hard winters (1995‑96 and 1996‑97) reduced the size of the state's northern deer herd, which in turn resulted in much lower deer harvests.

Wolves likely were accountable for a portion of the lower deer numbers and, in turn, the lower deer harvest. Subsequent mild winters resulted in a rebounding of the deer herd, despite the increasing wolf population.

The years 2005 through 2007 produced the highest deer harvests ever, with Minnesota deer hunters harvesting over 250,000 white-tailed deer during each of those hunting seasons - an approximate five-fold increase in hunter deer harvest since wolves were listed under the ESA in 1978.

Locally, the presence of wolves can reduce hunter success. The presence of wolves changes deer movements and behavior. Also some wolves hunt around bait piles that attract and concentrate deer, which may reduce the chances that deer will frequent the bait sites.


About Paul Tosto

Paul Tosto

Paul Tosto writes the Big Story Blog for MPR News. He joined the newsroom in 2008 after more than 20 years reporting on education, politics and the economy for news wires and newspapers across the country.