Wolves begin mating when they are 2 to 3 years old, sometimes establishing lifelong mates. Wolves usually rear their pups in dens for the first six weeks. Dens are often used year after year, but wolves may also dig new dens or use some other type of shelter, such as a cave.
Pups are born in early spring and are cared for by the entire pack. They depend on their mother's milk for the first month, and then they are gradually weaned and fed regurgitated meat by other pack members. By 7 to 8 months of age, when almost fully grown, the pups begin traveling with the adults.
Often, after 1 or 2 years of age, a young wolf leaves the pack and tries to find a mate and form its own pack.
Lone dispersing wolves have traveled as far as 500 miles in search of a new home. Wolf packs usually live within a specific territory. Territories range in size depending on how much prey is available and seasonal prey movement. Packs use a traditional area and defend it from other wolves. Their ability to travel over large areas to seek out vulnerable prey makes wolves good hunters.
Wolves may travel as far as 30 miles in a day. Although they usually trot along at 5 mph, wolves can attain speeds as high as 45 miles per hour for short distances. Indirectly, wolves support a wide variety of other animal populations. Ravens, foxes, wolverines, and even bears feed on the remains of animals killed by wolves. Wolves also help regulate the balance between ungulates (hoofed animals) and their food supply.
Wolves are noted for their distinctive howl, which they use as a form of communication.
Biologists do not know all of the reasons why wolves howl, but they may do so before and after a hunt, to sound an alarm, and to locate other members of the pack when separated. Wolves howl more frequently in the evening and early morning, especially during winter breeding and pup rearing. Howling is also one way that packs warn other wolves to stay out of their territory.