Family: Canidae, Dogs view all from this family
Description A very large canid, usually grizzled gray, but showing great variation in color, ranging from white to black. Long, bushy tail with black tip. Nose pad 1 1/4” (33 mm) wide. Long legs. Male larger than female. Ht 26–38” (66–97 cm); L 4’3”–6’9” (130–205 cm); T 13 3/4–19 3/4” (35–50 cm); HF 8 5/8–12 1/4” (22–31 cm); Wt 57–130 lb (26–59 kg).
Endangered Status The Gray Wolf is on the U.S. Endangered Species List. It is classified as endangered in Colorado, Idaho, Michigan, Montana, North Dakota, South Dakota, Washington, Wisconsin, and Wyoming; and is classified as threatened in Minnesota. The Mexican Wolf subspecies is considered extinct in the United States. The Gray Wolf once ranged from Mexico to Canada and Alaska, from sea to sea. In the 20th century it was systematically eradicated from the lower 48 states with the approval and participation of the U.S. government. Westward expansion across the U.S. in the 1800s led to the near elimination of many of the large mammals that wolves traditionally preyed upon, including bison, deer, elk, and moose. With their hunting stocks depleted, wolves turned to domestic livestock for sustenance, and that was their fatal error. Bounty hunters tracked down and killed wolves until the 1960s. Wolves were poisoned, shot, tracked down with dogs, trapped, and dug out of their dens. Poisoned carcasses were left out for them, often to the detriment of other wild animals, including Bald Eagles, foxes, and bears. By the time Gray Wolves came under the protection of the Endangered Species Act in 1973, there were only a few hundred left in northern Minnesota. Recovery programs have been underway ever since. These have involved educating the public about wolves, restoring habitat and prey species, introducing wolves into various areas (including most recently the Mexican Wolf subspecies in the southern mountains of Arizona and New Mexico), and in some places compensating ranchers for livestock killed by wolves. Federal, state, and private organizations continue the quest to make the contiguous U.S. wolf-friendly.
Similar Species Coyote is much smaller, with smaller nose pad; holds tail at downward angle. Wolf carries tail straight out. Domestic dog’s tail curves upward.
Breeding Mates February–March; 1 litter of 1–11 young born April–June, after gestation of 63 days.
Habitat Open tundra and forests.
Range Once most of North America, now only Alaska, Canada, n Washington, n Idaho, n Montana, Isle Royale National Park in Lake Superior, and ne Minnesota. Reintroduced into various areas including Yellowstone National Park, Wyoming.
Discussion A social animal, the Gray Wolf lives in packs of 2 to 15, usually 4 to 7, formed primarily of family members and relatives, although sometimes two packs combine. The strongest male of a pack is normally the leader. Within the pack hierarchy, there are male and female hierarchies. The alpha male is dominant over the entire pack, both males and females, and he can go anywhere he wants and take anything he wants. The beta male is second in the hierarchy, but the alpha female may be dominant over some of the lower-ranking males. Dominance behaviors are open mouth and bared teeth, hair raised along the back, and ears erect and pointed forward.
The Gray Wolf runs with a bounding gait with its tail held horizontal. Except perhaps for the Caribou, this wolf travels more often and for greater distances than any other terrestrial animal. A large pack’s territory covers 100 to 260 square miles (260–675 sq km), traveled at regular intervals over such runways as animal trails, logging roads, and frozen lakes. Territories may overlap slightly, but packs usually avoid one another. If food is adequate, a pack may use the same range for many generations. The pack works together on a hunt, either chasing down its victim, usually by slashing tendons in the hindlegs, or forcing it to circle back to waiting pack members. Usually hunting at night, this animal feeds primarily on large mammals, including Moose, Caribou, and deer, but will also catch smaller ones, and sometimes eats berries, birds, fish, and insects. The wolf ideally needs about 3 3/4 pounds (1.7 kg) of food per day, but it can go for two weeks or more without food. It gorges itself when food is plentiful.
Wolves gain an advantage over large prey in deep, crusted snow: The crust is able to support wolves, but a Moose or deer may break through and be unable to run efficiently enough to escape. However, a healthy deer can outrun wolves unless hindered by the snow. Myth notwithstanding, wolves do not often attempt long chases, although occasionally they may run for several miles. They can gallop and bound over short distances at speeds of more than 30 mph (50 km/h), but if they cannot capture running prey within about 1,000 yards (meters), they usually abandon the attempt. Wolves try to surprise a prey animal and cut off its retreat, or ambush it. When an animal runs away, the wolf’s instinct is to dash after it, but it is soon apt to give up such a chase unless the pursued creature stops and starts intermittently. Wolves, like many other carnivores, test prey: A Moose that stands and fights often persuades a pack to seek an easier quarry, but one that first defends itself and then runs—perhaps because it is injured, sick, defective, or very young or old—signals the possibility of its defeat, and the pack often continues to pursue it. In deep snow, wolves will follow humans or dog teams in order to take advantage of the tamped trail.
The Gray Wolf makes various whines, yelps, growls, and barks, although not all wolves are capable of barking. The most common bark is short, harsh, and uttered in a brief series. Howls, used to keep the pack together, may be at a constant pitch, may rise and fall, or rise and break off abruptly, sounding anywhere from dismal to beautiful and haunting. The howl of one wolf seldom lasts more than five seconds, but others in the pack may take it up, producing a chorus that continues until the animals tire or disperse. Many wolves answer a bark—even a poor human imitation of one—by howling. They produce a communal howl sometimes in early morning, but most often in the evening, when it may stimulate the urge to hunt. It usually begins with a few sharp barks by one or more pack members, which are often followed by a low, rather querulous howl that, in turn, stimulates steadier, louder communal howling that dies away after a few minutes, often ending with a few more barks before the pack goes off together to hunt. A wolf separated from its pack may give the “lonesome howl”—a shortened call that rises in pitch and then dies away plaintively. If answered, the wolf switches to a “location,” or “assembly,” howl—deep, even, and often punctuated by barks. A wolf seldom calls when actually chasing prey; rather, it stops to vocalize in order to maintain contact and sometimes calls to signal arrival at an ambush point toward which other pack members will then attempt to drive the quarry.
The Gray Wolf normally does not use a shelter except as a maternity den. During a blizzard, it curls its tail over its paws and nose and soon becomes covered with snow, which provides insulation from the cold. Wolves mature in their second year, but usually do not breed until their third. They mate for life. The den is in an enlarged chamber without nesting material, and usually on high ground near water. There may be several entrances, up to 2 feet (30–60 cm) in diameter. The tunnel usually is about 4 to 17 feet (1.2–5.2 m) long, though it may be longer. The same den may be used for years, although the young may be moved between dens at times. All members of the pack help to care for the young. At three weeks, pups emerge to play near the den entrance guarded by an adult. The rest of the pack leaves the den site in late afternoon or at dusk to hunt, usually returning the next morning with food. Pups jump and bite at the snouts and throats of returning hunters, stimulating them to regurgitate undigested meat, which the pups and their guardian devour. At about two months, the young are moved from the natal den to one of a series of “rendezvous sites,” usually near water, where they play and learn to hunt. By late summer, they begin to hunt with the adults. Some juveniles leave the adults at one year, some at two years, when mature.
The life span of the Gray Wolf is 10 to 18 years. Humans are the wolf’s only important predator, having persecuted the animal unnecessarily over the years. While humans have long feared wolves, there have been only three documented attacks by wolves on humans in North America, and none led to a fatality.
