The gray wolf or common wolf (Canis lupus) is the largest extant member of the dog family of mammals, the Canidae. The specieswas the world's most widely distributed mammal but has become extinct in much of Western Europe, in Mexico and much of the USA. Wolves occur primarily but not exclusively in wilderness and remote areas. Their original worldwide range has been reduced by about one-third by deliberate persecution due to depredation on livestock and fear of attacks on humans. 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.
Though once abundant over much of Eurasia, North Africa and North America, the gray wolf inhabits a reduced portion of its former range due to widespread destruction of its territory, human encroachment, and the resulting human-wolf encounters that sparked broadextirpation. Today, wolves are protected in some areas, hunted for sport in others, or may be subject to population control or extermination as threats to livestock, people, and pets.
Gray wolves are social predators that live in nuclear families consisting of a mated pair, their offspring and, occasionally, adopted immature wolves. They primarily feed on ungulates, which they hunt by wearing them down in short chases. Gray wolves are typicallyapex predators throughout their range, with only humans and tigers posing significant threats to them.
Genetic studies reaffirm that the gray wolf is the ancestor of the domestic dog. A number of other Canis lupus subspecies have been identified, though the actual number of subspecies is still open to discussion.
In areas where human cultures and wolves both occur, wolves frequently feature in the folklore and mythology of those cultures, both positively and negatively.
Wolves primarily feed on medium to large sized ungulates (up to the size of bison 10–15 times larger than themselves), though they are not fussy eaters. Medium and small sized animals that may supplement the diet of wolves include marmots, beaver, hares, badgers, foxes, weasels, ground squirrels, mice, hamsters, voles and other rodents, as well asinsectivores. They frequently eat waterfowl (particularly during their moulting period and winter, when their greasy and fatty meat helps wolves build up their fat reserves) and theireggs. When such foods are insufficient, they will prey on lizards, snakes, frogs, rarely toads and large insects as available. In times of scarcity, wolves will readily eat carrion, visiting cattle burial grounds and slaughter houses. Wolf packs in Astrakhan will hunt Caspian seals on the Caspian Sea coastline. Some wolf packs in Alaska and Western Canada have been observed to feed on salmon. Cannibalism is not uncommon in wolves; during harsh winters, packs often attack weak or injured wolves, and may eat the bodies of dead pack members. However, they are not known to eat their young as coyotes sometimes do. Humans are rarely, but occasionally preyed upon (see Attacks on humans). Wolves will supplement their diet with fruit and vegetable matter; they willingly eat the berries of mountain ash, lily of the valley, bilberries, blueberries andcowberry. Other fruits include nightshade, apples and pears. They readily visit melon fields during the summer months. Wolves can survive without food for long periods; two weeks without food will not weaken a wolf's muscle activity.
In Eurasia, many wolf populations are forced to subsist largely on livestock and garbage in areas with dense human activity, though wild ungulates such as moose, red deer, roe deer andwild boar are still the most important food sources in Russia and the more mountainous regions of Eastern Europe. Other prey species include reindeer, argali, mouflon, wisent, saiga,ibex, chamois, wild goats, fallow deer and musk deer. The prey animals of North American wolves have largely continued to occupy suitable habitats with low human density, and cases of wolves subsisting largely on garbage or livestock are exceptional. Animals preferred as prey by North American wolves include moose, white-tailed deer, elk, mule deer, bighorn sheep, Dall's sheep, American bison, muskox and caribou. In North Africa, wolves feed on various cultivated crops and vegetables and domestic animals.