Gray Wolf: Encyclopedia II - Gray Wolf - Reproduction and mortality

Gray Wolf - 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 between January and May, happening later in the year as latitude increases. Wolves, unlike dogs, only mate once a year. A pack usually procures one litter, though sometimes multiple litters will be born if the alpha male mates with one or more subordinate females. Under normal circumstances, the alpha female will try to prevent this by aggressively dominating other females and physically separating them from the alpha male.

The gestation period lasts 60 to 63 days, and the pups are born blind, deaf, and completely dependent on their mother. There are 1–14 pups per litter, with the average litter size being about four to six. Pups reside in the den, where they are born, and stay there until they reach about 8 weeks of age (the den is usually near an open water source, and has an open "room" at the end of an underground/hillside tunnel that can be up to a couple meters long). During this time, the pups will become more independent, and will eventually begin to explore the area immediately outside the den before gradually roaming up to a mile away from it. They begin eating regurgitated foods at four weeks – by which time their milk teeth have emerged – and are weaned by six weeks. During the first weeks of development, the mother usually stays with her litter alone, but eventually most members of the pack will contribute to the rearing of the pups in some way. ^[12]

After two months, the restless pups will be moved to a rendezvous site, which gives them a safe place to reside while most of the adults go out to hunt. An adult or two will stay behind to ensure the safety of the pups. After a few more weeks, the pups are permitted to join the adults if they are able (they tag along as observers until about eight months, by which time they are large enough to actively participate), and will receive first dibs on anything killed, their low ranks notwithstanding. Letting the pups fight for the right to eat results in a secondary ranking being formed among them, and lets them practice the dominance/submission rituals that will be essential to their future survival in pack life.

Wolves typically reach sexual maturity after two or three years, at which point many of them will feel compelled to leave their birth packs and search out mates and territories of their own. Wolves that reach maturity typically live between 6 and 9 years in the wild, although in captivity they can live to be twice that age. High mortality rates result in a relatively low life expectancy for wolves on an overall basis. Pups die when food is scarce; they can also fall prey to other predators such as bears, or, less likely, coyotes, foxes, or other wolves. The most significant mortality factors for grown wolves are hunting and poaching by humans, car accidents, and wounds suffered while hunting prey. Wolves are susceptible to the same infections that affect domestic dogs, such as mange, heartworm, rabies and canine distemper, and such diseases can become epidemic, drastically reducing the wolf population in an area. Wolves are sensitive to fluctuations in prey abundance, making them likely to experience minor changes within their own populations. At the same time, this balance between wolves and their prey prevents the mass starvation of all species involved.

Adapted from the Wikipedia article "Reproduction and mortality", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki