Admissions at Northland
Wolf Biology FAQs
Why did wolves disappear?
State and federal bounties (no longer in effect), loss of habitat, poaching, car kills, disease, starvation and parasites have all contributed to their decline. Today, thanks largely to protection afforded by the 1973 Endangered Species Act, wolf populations have returned and are growing in the Upper Midwest.
How did wolves return to the Upper Great Lakes region?
Wolves were not introduced or transplanted in Minnesota, Wisconsin and Michigan from other states or countries as some believe, although in 1974 an unsuccessful attempt to reintroduce four wolves to Michigan's Upper Peninsula from Minnesota occurred. All four were dead within one year. Unlike the reintroduction effort in Yellowstone National Park and central Idaho, wolves of Minnesota, Wisconsin and Michigan returned on their own. With the protection of the Endangered Species Act, wolves have been allowed to return without legal persecution from humans. Wolves emigrated from Ontario, into Minnesota. From Minnesota, wolves have moved into Wisconsin and Michigan's western Upper Peninsula. Wolves also emigrated from Ontario via the islands adjacent to Sault Ste. Marie, Michigan and moved into the eastern Upper Peninsula.
How
does a wolf pack form and what is the size of a pack?
Wolves are social animals and live in a family group
known as a pack. Even though a pack is a very tight knit unit
it will, on occasion, allow other subordinate adults to join.
Evidence indicates that the formation of wolf packs is based
on environmental and habitat characteristics. Many wolf packs
contain six to ten members, although this number may vary
depending on the number of pups or yearlings staying with
the pack from year to year. A pack could also be as small
as two members, although those members need to be the alpha
male and female.
How do individual
wolves become the leaders in the pack?
The leaders, or dominant wolves in a pack are called
the alpha pair. There are usually the male and female wolves
that have mated in the past and they are usually the only
wolves in the pack to breed. They also select den and rendezvous
sites. They can be recognized in a pack by tail position,
with dominant wolves tending to hold their tails straight
out. This posture is exhibited in normal social encounters
as well as when an alpha asserts its dominance. The pack is
a hierarchy. Struggles for dominance continually takes pace
and an alpha wolf which shows weakness may be replaced.
When
do female wolves start to breed and how many pups can they
have?
A female wolf is able to breed when it is about two
years old but does not normally breed until it is three to
four. Usually the alpha pair of the pack will suppress breeding
in younger wolves. The breeding period is normally from late
January to early March with a 63-day gestation period. The
average litter is 5 or 6 pups. In most cases, the dominate
pair are the only pack members that mate, although occasionally
another male or female will be allowed to mate with one of
the alphas.
What comprises a wolf's diet?
Pups are dependent on the female until they are weaned at six weeks and begin to eat meat. Adult wolves will eat meat at a kill site then return to the den or rendezvous site and regurgitate the food for the pups. To stimulate regurgitation, the pups jump and nip the adult's muzzle.
Wolves are meat-eaters or carnivores. White-tailed deer are the most important food item for wolves in Wisconsin and Michigan. A study found deer comprise 55 percent of the diet. Other important items in the diet were beaver (16 percent) and snowshoe hare (10%). Beaver are normally eaten during the ice-free period, and hare are taken in larger numbers during the highs in the hare population cycle. Major food sources used by wolves in other locations include: moose, elk, caribou, bison and musk ox. Wolves do not generally spend too much time chasing small animals like voles or mice because they use up too much energy for a limited energy return.
How long do wolves live?
Wolves have been known to live up to 13 years in the wild. Mortality is generally very high during their first year of life. Usually only about one half of the pups produced by a pack survive to be one year old. Dispersing wolves also experience high mortality rates, but once adult wolves settle into a secure territory, their chance of survival greatly increases and many achieve ages of six to seven years or more.