Members of the Family:Fox, coyote and domestic dogs. Members of this Species include the Arctic Wolf Canis lupus arctos, and the Mexican Gray Wolf Canis lupus baileyi.
Conservation Status:Delisted (recovered) in Idaho, Montana, Oregon, Utah, Washington, and Wyoming. Threatened in Minnesota, Wisconsin and Michigan. Endangered in Arizona, Colorado, Illinois, Indiana, Iowa, Missouri, New Mexico, North Dakota, Ohio, Oregon, South Dakota, Utah, and Washington.
Geographic Range and Habitat:The gray wolf inhabits prairies, forests, and desserts of Canada, the United States and Mexico.
Physical Description:Gray wolves are the largest of the 41 wild canid species. Males are larger than females. Geographically, gray wolves vary in size based primarily on locality, with southern populations generally smaller than northern populations. Fur color of gray wolves also varies geographically, ranging from mixtures of white with gray, brown, cinammon, and black to nearly uniform black in some color phases.
Weight:50 to 175 lbs (23 to 80 kg)
Length:34 to 51 in (870 to 1300 mm)
Reproduction:Gray wolves breed once each year, generally between January and March based on their geographic location. In a pack of wolves, only the dominant, or alpha, male and female will breed. This pair is monogamous although, with the death of an alpha individual, a new alpha male or female will emerge and take over as the mate. The female digs a den after mating in preparation for the birth of her litter. Pups are born in the den and remain there until they are 8 to 10 weeks old. Pups are protected by the entire pack and the beta wolves, or second most dominant, may help feed them by providing regurgitated meat.
Gestation Period:63 days (high)
Number of Offspring:5 to 14; avg. 7
Birth Weight:Approximately 16 oz (450 g)
Time to Weaning:45 days (average)
Age at Sexual or Reproductive Maturity:2 to 3 years
Average Lifespan (Wild):Gray wolves may live thirteen years in the wild, though average lifespan is 5 to 6 years. As adults they usually die from old age or from injuries received while hunting or fighting with other wolves. In captivity they may live to be fifteen years of age.
Average Lifespan (Captivity):15 to 20 years
Social Habits:Gray wolves are highly social, pack-living animals. Each pack comprises two to thirty-six individuals, depending upon habitat and abundance of prey. Most packs are made up of 5 to 9 individuals. Packs are typically composed of an alpha pair and their offspring, including young of previous years. Unrelated immigrants may also become members of packs.
There is a strong dominance hierarchy within each pack. The pack leader, usually the alpha male, is dominant over all other individuals. The next dominant individual is the alpha female, who is subordinate only to the alpha male. In the event that the alpha male becomes injured or is otherwise unable to maintain his dominance, the beta male will take his place in the hierarchy. Alpha males typically leave the pack if this occurs, but this is not always the case. Rank within the pack hierarchy determines which animals mate and which eat first. Rank is demonstrated by postural cues and facial expressions, such as crouching, chin touching, and rolling over to show the stomach.
Behavior:Rank is communicated among wolves by body language and facial expressions, such as crouching, chin touching, and rolling over to show their stomach.
Vocalizations, such as howling allows pack members to communicate with each other about where they are, when they should assemble for group hunts, and to communicate with other packs about where the boundaries of their territories are. Scent marking is ordinarily only done by the alpha male, and is used for communication with other packs.
Food Habits:Gray wolves are carnivores. They eat a variety of animals, depending on their location, by hunting on their own, or in packs. They may also steal the prey of other predators. As a pack Wolves may go after mammals include moose, elk, bison, musk oxen, and reindeer. Beavers, rabbits, and other small mammals are usually hunted by lone wolves. Wolves may also eat livestock and garbage when it is available.
Known Predators:Few animals prey on gray wolves. Wolves are highly territorial animals so wolves from other packs will attack wolves that are alone or young.
Wolves play an important role in nature as top predators, because they regulate populations of their prey animals and remove weak individuals. Wolf ecotourism in National Parks and lands with wolf populations is a viable source of revenue.
Wolves may sometimes kill livestock. The extent of livestock loss to wolves is often overstated, wolves typically prefer their wild prey.
Additional Conservation Information: As settlement increased, the belief that livestock was endangered by wolf populations also increased. As such, the frequency of hunting the gray wolf exploded. The populations were nearly eradicated. Currently in the lower 48 United States, about 2,600 gray wolves exist, with nearly 2,000 in Minnesota (compared to the few hundred living there in the mid-20th century). Successful recovery plans have been developed throughout the country. These plans evaluate the populations to determine distribution, abundance, and status. The main cause of population declines has been habitat destruction and persecution by humans. But the reintroduction of gray wolves into protected lands has greatly increased the likelihood of their survival in North America. Populations in Alaska and Canada have remained steady and are fairly numerous. Currently the State of Alaska manages 6,000 to 8,000 gray wolves and Canada's populations are estimated at about 50,000. The wolves in Canada are managed by provincial governments and are not currently threatened.
In western Eurasia gray wolf populations have been reduced to isolated remnants in Poland, Scandinavia, Russia, Portugal, Spain, and Italy. Wolves were exterminated from the British Isles in the 1700's and nearly disappeared from Japan and Greenland in the 20th century. Greenland's wolf populations seem to have made a full recovery. The status of wolf populations throughout much of eastern Eurasia is poorly known, but in many areas populations are probably stable.
To Cite This Page:Dewey, T. and J. Smith. 2002. "Canis lupus" (On-line), Animal Diversity Web. Accessed December 09, 2009 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Canis_lupus.html.
US Fish and Wildlife Service (on-line). Accessed December 11, 2009 at http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A00D
For more information: http://www.fws.gov/endangered/factsheets/gray_wolf_factsheet.pdf