Usually only the alpha pair breeds, however, in areas where there
is a high ratio of prey per wolf there can be multiple litters per pack.
In the basics wolves breed in February through March and have
an average of six pups. The gestation period is 63 days so pups are
born in April or May.
Pup survival is directly related to prey availability. Prey availability
is generally higher in areas that are being newly colonized by wolves,
where wolves have been recently reintroduced, or where adult wolves
Adult Survival and Longevity
The overall survival of yearling and adult wolves has been documented to vary between 60% and 80%.
Gray wolves are known to live up to 13 years in the wild and 15
years in captivity.
Pack and Territory Size
The number of individuals per pack can be highly variable, but averages
four to eight during winter with records of up to 16. Pack size can be as high as 30 or more.
A wolf pack will roam and defend a territory of between 42 and 100 miles.
Dispersal and Ability to Colonize New Areas
Dispersal is the primary way wolves colonize new areas and maintain
genetic diversity. Wolves have been known to disperse up to 550
miles, but more commonly disperse 50 - 100 miles from their natal
pack. Generally wolves disperse when 1 - 2 years old although some
adults disperse also. At any one time 5 - 20% of the wolf population
may be dispersing individuals. Usually a wolf disperses to find
an individual of the opposite sex, find a territory, and start a
new pack. Some dispersers join packs that are already formed.
Wolves can occur wherever there is a sufficient number of large
ungulates such as deer, moose, elk, bison, and musk ox. Wolves were
once considered a wilderness animal, however, if human-caused mortality
is kept below certain levels, wolves can live in most areas. Historically,
they once occupied every habitat that had sufficient prey in North
America from mid Mexico to the polar ice pack.
Wolves can survive on 3.7 pounds of food per day, but require about
five pounds per day to reproduce successfully. Wolves are estimated
to eat 10 pounds of food per day on average. Wolves don't actually
eat every day, however, as they live a feast or famine lifestyle.
They may go several days without a meal and them gorge on over 20
pounds of meat when a kill is made. Wolves primarily feed on white-tailed
deer, but supplement their diet with moose, beaver, hare, and other animals.
Reductions in the deer herd caused by wolves increases habitat
quality and helps rid the herd of genetically unfit and diseased
individuals. This results in long term maintenance of a healthier
deer herd. Deer and wolves have evolved together and wolf predation
has played a crucial role in making the deer what it is today.