Mean litter size is 6 young, weighing about 450 gms at birth and are born blind and deaf. The pups are completely dependent on their mother for their first two months of life. Their eyes open during their second week and they have begun to explore outside the den by three weeks. The pups are generally weaned by the age of 6-8 weeks, with the help of the other members of the pack helping feed the young by regurgitating partially digested meals. Young gray wolves reach sexual maturity by the age of one and may leave the pack at the age of two , adopting a solitary lifestyle for some time, before pairing up and establishing a territory of their own.
Mortality is highest among the young.
In times of sharply declining food supplies, all pups may be severely underweight or die from malnutrition, and reproduction may even cease. For adults in such a situation, the primary mortality factor has been found to be intraspecific competition. In the wild, ten years is considered an old age for a wolf, but captive wolves have been documented in excess of twenty years old. Movement of the gray wolves is extensive during the daylight hours and at night time under normal conditions, although diurnal activity increases in extremely cold weather. During the summer, the pack usually sets out in the early evening and returns to the den by the next morning.