The gray wolf is the largest wild species in the dog family, Canidae. It has a powerful, muscular body, long legs, and a relatively narrow chest that helps it travel efficiently over long distances. Its head is broad, gradually narrowing toward the muzzle, while its thick, bushy tail is often marked with a black tip.

A gray wolf has a dense, rough outer coat combined with a thick layer of underfur that helps protect it from cold and severe weather. Fur coloration can differ considerably, ranging from nearly pure white among some Arctic wolves to combinations of gray, brown, cinnamon, and black. Some individuals may be almost entirely black or white. Geographic conditions and genetic differences both contribute to this wide range of colors.

Gray wolves also vary in size according to where they live. Wolves from northern regions are generally larger than those farther south. Adult males commonly weigh about 70–145 pounds (32–65 kilograms), while females generally weigh between 60 and 100 pounds (27–45 kilograms). Their bodies measure roughly 3–5 feet (0.9–1.5 meters) long, with the tail contributing another 1–2 feet (0.3–0.6 meters). They typically stand about 26–33 inches (66–84 centimeters) at the shoulder.

Range

Historically, gray wolves occupied enormous portions of the Northern Hemisphere, including Europe, Asia, and North America. In the United States, they once inhabited more than two-thirds of the country and could be found in environments ranging from the forests of New England to the deserts of the Southwest.

Extensive campaigns aimed at eliminating predators, combined with habitat destruction, caused wolves to disappear from most of the contiguous United States by the middle of the twentieth century.

Today, gray wolves have recovered in several parts of their former range. They remain widely distributed throughout Alaska, while important populations in the lower 48 states occur in the Northern Rockies, particularly Montana, Idaho, and Wyoming. Strong populations are also found around the western Great Lakes in Minnesota, Wisconsin, and Michigan.

Smaller populations have become established in Washington, Oregon, Colorado, and California, expanding the species' presence into additional areas of its historic range.

Diet

Gray wolves are meat-eating predators that depend heavily on large hoofed mammals, also known as ungulates. Common prey includes elk, moose, deer, bison, and caribou. Which animals they pursue depends largely on what is available in their particular region and during different seasons.

For example, elk and deer make up important prey in the Northern Rockies, while wolves living in Arctic environments encounter and hunt animals such as caribou and muskoxen more frequently. Wolves commonly work together in packs, using coordinated movements to separate and overpower large prey. They can also hunt alone when pursuing smaller animals.

Their diet is not limited to large mammals. Gray wolves may also eat beavers, hares, rodents, birds, and occasionally fish. The coastal wolf population around Vancouver is sometimes referred to as “sea wolves” and is recognized as a distinct subspecies because of its semi-aquatic habits and tendency to catch fish.

When opportunities arise, wolves will also feed on carrion. They may consume berries and other fruits when animal prey is limited. This flexible feeding strategy helps them survive in a broad range of habitats and cope with changes in food availability.

Gray wolves are capable of consuming enormous quantities of food after a successful hunt. An adult can eat as much as 20 pounds of meat during a single meal. At other times, however, wolves may survive for several days without finding enough prey to eat.

Life History

Gray wolves are highly social animals that normally live in packs. A typical pack contains around four to nine individuals, although groups may consist of only two wolves or reach approximately 15 members. In exceptional situations, a pack can grow to around 30 animals before some members leave to establish new territories.

A wolf pack generally consists of a breeding pair along with offspring from several generations. As young wolves mature, some eventually leave their family group and become dispersing “lone wolves.” They travel in search of suitable territory and a partner with which to establish a new pack.

When prey is plentiful, a young wolf may establish a territory relatively close to its original pack. In regions where suitable habitat is limited, however, dispersing wolves can travel hundreds of miles before finding an appropriate place to settle.

Gray wolf breeding pairs commonly remain together for life. If one partner dies, the surviving wolf may eventually find another mate. In northern parts of the United States, breeding usually takes place between late January and March, while wolves living farther south tend to breed earlier.

Pregnancy lasts approximately 63 days, after which a female generally gives birth to four to six pups.

Wolf Pups and Family Care

Newborn pups are usually delivered inside a den. At birth, they are unable to see or hear and weigh approximately one pound. They gradually develop and are generally weaned at around six weeks of age.

Because adult wolves may travel considerable distances from the den while searching for prey, pack members have an unusual way of bringing food home. They swallow meat after a successful hunt and later return to the den, where they regurgitate the food for the young wolves to eat.

The mother may move her pups to different den locations every couple of months to help protect them. By autumn, the pack generally stops relying on permanent den sites.

In the wild, gray wolves commonly live for approximately 8–13 years, although some survive longer. Individuals kept under human care can live for more than 15 years.

Conservation

Gray wolves have historically suffered major population losses because of habitat destruction, deliberate predator-control campaigns, conflicts involving livestock, and continued persecution by people. Although certain populations are stable or increasing, their overall numbers remain considerably lower than they were historically.

Large and healthy wolf populations continue to occur in Alaska and Canada. In the lower 48 states, wolves were largely eliminated from their former range by the middle of the twentieth century, with the upper Great Lakes region being one of the major exceptions.

A significant step in their recovery occurred in 1995, when gray wolves were reintroduced into Yellowstone National Park. The population established itself successfully in the Northern Rockies and subsequently expanded into parts of the Pacific Northwest and northern California.

Wolf restoration has also begun in Colorado, where the first animals were released onto public lands in December 2023. The Mexican gray wolf, a subspecies of gray wolf, has likewise been reintroduced into portions of Arizona and New Mexico.

Research conducted in Yellowstone has demonstrated that returning wolves to areas where they historically lived can restore their ecological role as apex predators and contribute to healthier, more naturally functioning ecosystems.

For current information about gray wolf conservation and population status in specific areas of the United States, NatureServe Explorer provides additional regional information.

Fun Facts

A typical gray wolf needs roughly 5–7 pounds of meat each day to remain healthy and support reproduction.

Gray wolves use an elaborate combination of sounds and body movements to communicate. A submissive wolf may lower its body, whine, tuck its tail, lick another wolf around the mouth, or roll onto its back to signal submission.

The popular idea that a “lone wolf” represents independence and superiority is misleading. Gray wolves are strongly social animals. A wolf traveling alone is often a young individual dispersing from its original pack in search of a mate and a new territory. Living alone can actually make survival more difficult.

Older wolf siblings can help care for younger pups while the adults are away hunting. They may protect the pups, bring them food, and interact with them through play.