Some researchers estimate that a wolf can run as fast as 40 miles an hour. Wolves have been known to travel 120 miles in a day, but they usually travel an average of 10 to 15 miles a day. Wolves live, travel, and hunt in packs of four to seven animals, consisting of an alpha, or dominant pair, their pups, and several other subordinate or young animals. The alpha female and male are the pack leaders, tracking and hunting prey, choosing den sites, and establishing the pack's territory. The alpha pair mate in January or February and give birth in spring, after a gestation period of about 65 days.
Litters can contain from one to nine pups, but usually consist of around six.
Pups have blue eyes at birth and weigh about one pound. Their eyes open when they are about two weeks old, and a week later begin to walk and explore the area around the den. Pups romp and playfight with each other from a very young age. Scientists think that even these early encounters establish hierarchies that will help determine which members of the litter will grow up to be pack leaders. Wolf pups grow rapidly, reaching 20 pounds at two months and full size in a year.