Wolves are carnivores, or meat eaters. Gray wolves prey primarily on ungulates – large, hoofed mammals such as white-tailed deer, mule deer, moose, elk, caribou, bison, Dall sheep, musk oxen, and mountain goats. Medium-sized mammals, such as beaver and snowshoe hares, can be an important secondary food source. Occasionally wolves will prey on birds or small mammals such as mice and voles, but these are supplementary to their requirements for large amounts of meat. Wolves have been observed catching fish in places like Alaska and western Canada. They will also kill and eat domestic livestock such as cattle and sheep, and they will consume carrion if no fresh meat is available. Some wolves eat small amounts of fruit, although this is not a significant part of their diet. If prey is abundant, wolves may not consume an entire carcass, or they may leave entire carcasses without eating. This is called “surplus killing” and seems inconsistent with the wolves’ habit of killing because they are hungry. Surplus killing seems to occur when prey are vulnerable and easy to catch – in winter, for instance, when there is deep snow. Since wolves are programmed to kill when possible, they may simply be taking advantage of unusual situations when wild prey are relatively easy to catch They may return later to feed on an unconsumed carcass, or they may leave it to a host of scavengers. Additionally, they may cache food and dig it up at a later time.
Red wolves primarily prey on white-tailed deer, raccoons, rabbits, nutria and other rodents.
Getting enough to eat is a full-time job for a wolf. When wolves catch and kill a large mammal, they will gorge and then rest while the food is being rapidly digested. They will generally consume all but the hide, some of the large bones and skull and the rumen (stomach contents of ungulates) of their prey. Gray wolves can survive on about 2 1/2 pounds of food per wolf per day, but they require about 7 pounds per wolf per day to reproduce successfully. The most a large gray wolf can eat at one time is about 22.5 pounds. Adult wolves can survive for days and even weeks without food if they have to. Growing pups, however, require regular nourishment in order to be strong enough to travel and hunt with the adults by the autumn of their first year. Wolves often rely on food they have cached after a successful hunt in order to see them through lean times.
Red wolves may eat 2 to 5 pounds of food per day when prey is abundant. Because they are smaller than gray wolves, they can consume less at one time than their larger cousins. But like all wolves, eating for red wolves is a matter of “feast” followed by “famine.”
Wolves depend on a variety of large ungulates (hoofed animals) for food. Although studies have been conducted in some areas to determine the actual number of prey killed each year, the results are estimates. For example, an estimate for deer ranges from 15 to 19 adult-sized deer per wolf per year. Given the 2008 estimate of 2922 wolves in Minnesota, for instance, that would equal 43,800 to 58,500 deer killed by wolves. In comparison, hunters killed approximately 260,000 deer in the 2007 deer harvest. Additionally, several thousand deer are killed during collisions with vehicles each year.
*Thanks to the International Wolf Center for providing this information!