Wolves are highly social and live in packs. The pack usually consists of a dominant breeding pair (an alpha male and alpha female), their offspring from the previous year, and new pups. Other breeding age adults may be present, but usually only one pair will breed in each pack in any given year. The pack often hunts, feeds, travels, and rests together, although they may split up from time to time to patrol their territory or search for food. It also shares pup-rearing responsibilities, including hunting and tending pups. Pack size is highly variable, and commonly averages about four to five wolves per pack, but can range from two to 15 animals.
Few wolves live more than five years in the wild, although individuals have been known to reach 15 years of age. Research in the northern Rocky Mountain states has shown that humans cause most wolf deaths in the region. Causes include illegal killings, legal harvest, vehicle collisions, and management removals.
However, in areas such as Yellowstone National Park, where wolves are fully protected, most wolves die from natural causes, such as territorial conflicts with wolves in neighboring packs, injuries while hunting prey, starvation, or disease.
Wolves usually mate in mid to late February, and the pups are born about two months later. Most packs produce one litter annually, typically consisting of four to six pups. Wolves often develop dens in underground burrows, but also use abandoned beaver lodges, hollow trees, and shallow rock caves.
As pups grow older, they are taken from the den to a protected location known as a rendezvous site. A rendezvous site is where the pack will take young wolves before they’re able to travel and hunt with the pack. One or more rendezvous sites are used over the summer until the pups have matured.
With their large size, powerful jaws, large teeth, speed, endurance, and habit of hunting in packs, wolves are keenly adapted to hunt large prey. In the central and northern Rocky Mountains of the U.S. and Canada, wolves often prey on elk, deer, and moose. Despite their hunting abilities, the majority of wolf hunts are unsuccessful.
Wolves are opportunistic hunters and tend to prey mainly on younger, older, and debilitated animals. This can leave prey herds with more healthy animals of prime age, thereby enhancing productivity.
Wolves will also scavenge carrion and eat smaller animals. In some instances, wolves have been known to kill and feed on domestic livestock and poultry, including cattle, sheep, and chickens.
A pack establishes a territory and defends it against neighboring packs. Territories usually average 140 to 400 square miles, and their size often varies from year to year. Territories are often smaller when prey is more plentiful and other packs live nearby.
Howling is a common behavior that helps pack members communicate and stay together. Howls are audible for up to five miles. The howls of wolves tend to be long and drawn out compared to the shorter yapping sounds made by coyotes. Wolves also growl and bark.
Most young wolves leave their birth packs when they are 2 or 3 years old to search for a mate and start a new pack of their own. Dispersing wolves usually relocate about 60 miles from their birth pack, but can travel up to 500 miles or more.
They are highly adaptable and can live in a variety of habitats if sufficient prey is available. In the northwestern states and western Canada, wolves are most common in relatively flat forested areas, rolling hills, or open spaces such as river valleys and basins, where prey animals are easier to chase and catch.
Wolf populations fare best in areas away from humans and their activities. These tend to be remote, relatively unpopulated areas with extensive public lands, few roads, and few or no livestock.
The presence of wolves can benefit natural plant and animal communities by preventing the overpopulation of prey and helping maintain the natural occurrence of certain plant and wildlife species.
Wolves support scavenging animals
The availability of carcasses from wolf kills can help scavenging animals, such as bald eagles, bears, wolverines, foxes, mink, ravens, magpies, jays, crows, golden eagles, and vultures. This benefit is especially important during the winter, when other foods become scarce.