While the most recognizable stage of the grey wolf's life cycle is the large imposing adult, these animals go through several stages from conception to death. The average wolf lives six to eight years in the wild. It grows from a pup to a reproducing adult in two to three years.
Wolves generally breed once per year in time for the weather to begin to warm before the pup is born. The gestation period is 63 days, and the average litter is four to six pups, each weighing about 1 pound. Newborn pups are blind and deaf. For the first 21 days, the pups nurse every four to six hours and depend on the mother to help regulate their body temperature. Other pack members bring her food during this time.
The mother weans the pups after approximately eight weeks, and they begin eating food that the female or other members of the pack regurgitate for them. They start to learn the ways of the pack to be ready to travel with the adult wolves and join in hunts as the weather turns cooler. Upon reaching sexual maturity, wolves leave their original pack to find mates and their own territories. The adult gray wolf is 4.5 to 6 feet in length, with a shoulder height of 26 to 36 inches and weight between 50 and 110 pounds. Approximately half of all wolves die before reaching adulthood.