The gray wolf, grey wolf, or common wolf (Canis lupus) is the largest extant member of the dog family of mammals, the Canidae. Although the species still faces some threats, it is relatively widespread with a stable population trend and has therefore been assessed as Least Concern by IUCN since 2004.
The first federal Endangered Species Preservation Act was passed in 1966, and in 1967 gray wolves were classified as endangered and provided limited protection. In 1974, four subspecies of gray wolves in the lower 48 states (Canis lupus irremotus, C. l. lycaon, C. l. bailey, and C. l. monstrabilis) were afforded full protection under the federal Endangered Species Act (ESA) of 1973 (50 CFR 17.11(h)). In 1978, the gray wolf was relisted as endangered at the full species level (C. lupus) throughout the conterminous 48 States and Mexico, except for Minnesota where it was reclassified as threatened (50 CFR 17.11(h)).
Gray wolves were originally state listed as threatened in Minnesota in 1984, but as wolf numbers continued to increase, they were reclassified as state special concern in 1996. In January 2012, wolves in the western Great Lakes population, including Minnesota, were completely removed from the federal Endangered Species List.
Following a courtship period ranging from several days to months, copulation occurs between pack members, or lone individuals, any time from January to April. Individuals in packs show definite preferences for certain mates.
Although wolves are generally not prey-specific, large ungulates make up the majority of their diet. In the eastern portion of North America, white-tailed deer (Odocoileus virginianus) and moose (Alces alces) in single prey systems typically constitute the majority of a wolf’s diet. However, in the northern and western portions, many different combinations of ungulate species including elk (Cervus elaphus), moose, caribou (Rangifer tarandus), muskox (Ovibos moschatus), white-tailed deer, mule deer (Ododcoileus hemionus), black-tailed deer (O. h. columbianus), bighorn sheep (Ovis canadensis), and bison (Bison bison) can be available to wolves in a multi-prey system.
Because wolves are habitat generalists, they can live in most places in North America that have a sufficient prey base. Conflicts typically occur, however, when they occupy areas close to humans. The majority of wolf mortality is human-caused whether accidental, intentional or indirectly through disease.
During late spring, summer, and early autumn, gray wolves tend to be active at dusk and during the night, returning to their dens near sunrise. If pups are present they may be active during daylight hours. During colder months wolves tend to be active throughout the day and night.
Although wolves do not need "wilderness" (i.e. non-managed, roadless areas), they do need large areas of contiguous forest in which to range. They also need stable populations of their preferred prey. Wolf habitat is enhanced by timber cutting, wildlife habitat management and other practices that create more diverse and productive forests. Generally, a pack of wolves will roam an area of at least 100 square miles.
Originally, Gray Wolves had the largest distribution of any mammal except humans. Their geographic range was mainly in the Northern hemisphere spanning from the Arctic towards South America and Southern Asia. Today due to habitat destruction and environmental changes, the Gray Wolf is found only in the United States, Alaska, Canada, Mexico, and Eurasia.
The Gray Wolf is a highly social animal, and their pack size can vary a lot, but are usually made up of 5-12 members. However, packs can be made up of 20 or more members; these packs often eventually split up into smaller groups. Packs have complex social structures; there is a dominance hierarchy with a top male or female serving as the pack leader.
As adults, wolves average 30 inches in height at the shoulder and 65 pounds. Their feet are generally 3 1/2 inches wide and 4 1/2 inches long, and provide an easy way of differentiating wolves from coyotes, whose feet are only 1 1/2 inches wide and 2 1/2 inches long.