Reproduction and mortality

Normally, only the alpha pair of the pack breeds. This kind of organization also occurs in other pack-hunting canids, such as the Dhole and the African Hunting Dog. Mating usually occurs in February to May, and wolves, unlike dogs, only mate once a year. Another interesting fact about the social economy of wolves is that they are usually monogamous: the alpha pair will ordinarily mate exclusively with each other so long as they both remain alphas. There are times when one of the alphas will attempt to mate with a subordinate wolf, and if the other alpha is unable to prevent it, multiple litters can be born. This has been documented in Yellowstone amongst other places and usually occurs in large packs with plenty of available prey.

The gestation period is 60 to 63 days, and the pups are born blind and completely dependent on their mother. There are 114 pups per litter, with the average litter size being 6 or 7 pups. Pups reside in the den in which they are born until they reach 810 weeks of age. The mother usually stays with her litter alone for the first 3 weeks, but all members of the pack eventually help rear the pups. Pups consume food regurgitated by older wolves until they are 45 days old. They are fed meat provided by pack members after that age.

Female pups reach sexual maturity at 2 years of age, whilst males do so at 3 years of age. Most wolves leave their birth pack when they are 13 years old.

Wolves typically live 69 years in the wilderness, although in captivity they live 16 years on average. The record lifespan of a wolf is about 20 years of age. However, the mean age of wolves is rather low. The mortality among pups is high, and few survive the first winter. The most significant mortality factors for grown wolves are hunting and poaching by humans, car accidents, and wounds from hunting prey. All diseases that affect domestic dogs also affect wolves, including mange and rabies, and can from time to time wipe out the wolf population in an area. Wolves adjust rather well to fluctuations in prey populations, so mass starvation is unusual. Wolves are able to sustain their population under a heavy pressure, as long as the alpha pairs are not killed.

From Wikipedia