Gray Wolf

Identifying Characteristics: Hair color variable even within populations; litter mates often express great variety. White, cream-colored, buff, tawny, reddish, gray, black, and mottled combinations thereof. All black wolves possible due to early hybridization with domestic dogs. Graying with age. The Gray Wolf is the largest of the wild dogs.  About half the Gray Wolves in Montana are black with the other half gray. Both color phases may be found in a pack or in a litter of pups.

Total length: 70 to 73 inches.  Weight: 80 to 110 pounds.

Habitat: Found living in forest, prairie, tundra, desert, and swamp; even living near or within large cities. Adapted to live across an extreme range of temperatures. The Gray Wolf exhibits no particular habitat preference except for the presence of native ungulates within its territory on a year-round basis. Gray Wolves establishing new packs in Montana have demonstrated greater tolerance of human presence and disturbance than previously thought characteristic of this species. They have established territories where prey are more abundant at lower elevations than expected, especially in winter.

Food Habits: Gray Wolves are opportunistic carnivores that predominantly prey on large ungulates. Main prey items include deer, Elk, and Moose. Bison are also taken where the ranges of the two species overlap in and around Yellowstone National Park. Domestic livestock such as cattle and sheep are also preyed upon. Gray Wolves may also eat alternative prey, such as rodents, vegetation and carrion. Gray Wolves commonly hunt in packs, but lone animals and pairs are able to kill prey as large as adult Moose.

Life History: Active day and night; remain with young pups during daylight hours. Travel alone late spring to summer; pack members form nomadic hunting groups late summer to early spring. Hunt within a cooperatively defended territory.

Similar Species: Coyote

Ecology
In most areas, Gray Wolves are territorial throughout the year. Packs generally consist of a socially dominant pair, their offspring of the previous year, and new pups, although other breeding-age adults that may or may not be related to the alpha pair may also be present. More than 1 female in the pack can breed and give birth to pups. Pup survival when there are multiple litters is highly variable. Pack size varies and may include as few as 3 and as many as 37. In the Glacier National Park area, packs generally include 8 to 12 individuals. Packs share pup-rearing responsibilities including food provisioning and tending pups at the den or rendezvous sites. Pack activity is centered on the den site and nearby rendezvous sites from late April until September. Lone Gray Wolves may move through territories of established packs. Pack territories are dynamic and change from year to year depending on prey availability, Gray Wolf populations, and relationships with neighboring packs.

Summer home ranges are smaller than winter ranges; the annual range may be up to several hundred square miles. In the Glacier National Park area, territory size averages around 300 square miles. Gray Wolves may occasionally move several hundred miles, especially dispersing young.

Life Cycle
In Montana, Gray Wolves breed in mid- to late February, with gestation lasting about 63 days. A female can only give birth once a year. Breeding usually occurs between the dominant male and female in the pack and Gray Wolves normally do not breed until they are at least 22 months old. More than 1 female in a pack may breed, resulting in more than 1 litter per. Young are typically born in late April in an underground burrow that has been abandoned by another mammal or dug by Gray Wolves. In northwestern Montana litter sizes range from 1 to 9. Pups emerge from the den in about 3 weeks and are weaned in about 50 days. Young vacate the den when they are about 3 months old and move to a series of rendezvous sites throughout the pack's territory. The pups are large enough to travel with the entire pack by September. Some offspring remain with the pack and others disperse as they mature. Lone Gray Wolves generally do not successfully rear young, but they may if food is abundant.

Pup survival is variable and influenced by a number of factors including disease, predation, and nutrition. Pup mortality was most often attributed to human causes, but canine parvo virus was strongly suspected as a main factor in low pup survival in Yellowstone.

Migration
This species is not migratory but may move seasonally following migrating ungulates within its territory. Gray Wolves also disperse widely. Males in northwestern Montana can move an average of 70 miles from their natal territory, and females 48 miles, before establishing a new territory or joining an existing pack. Dispersal peaks twice per year; first in January/February and second, in May/June. Some Gray Wolves are known to have dispersed up to 500 miles. Dispersal has been documented from Canada, Idaho and Wyoming to Montana. Montana Gray Wolves are also known to have dispersed to Canada, Idaho, and Wyoming.

Background
The gray wolf was extirpated from the western United States during the 1900s, primarily due to loss of habitat and conflicts with people.

Although wolf packs were eliminated from Idaho by the 1930s, tracks, scat, and/or observations of large canid-like animals were either reported or those animals were killed up until the 1970s. Most are thought to have been dispersers from Canada and little to no successful breeding activity was evidenced or sustained consistently through time.

The U.S. Fish and Wildlife Service listed the northern Rocky Mountain gray wolf as endangered under the Endangered Species Act in 1973.

In 1980, the Northern Rocky Mountain Wolf Recovery Team completed a plan that would guide wolf recovery efforts for a future wolf population in the northern Rockies of Montana, Idaho, and Wyoming. The recovery plan was revised in 1987. The plan designated three recovery areas - Northwestern Montana, Central Idaho, and the Greater Yellowstone.

Wolves from Canada began to naturally colonize the Glacier National Park area in 1979, and the first wolf den in the western U.S. in over 50 years was documented there in 1986. The wolf population grew as a result of natural reproduction and dispersal. By the end of 1994, there were about 48 wolves in and around Glacier National Park.

In 1995, three family groups - a total of 14 wolves - were trapped captured near Alberta's Jasper National Park, transported to Yellowstone National Park, and placed in acclimation pens. Two of the females subsequently denned and produced nine pups in Montana.

Also in the winter of 1995, 15 wolves were reintroduced into the wilderness areas of central Idaho. These animals moved widely throughout central Idaho and beyond. Many of these wolves moved north, some to the upper Bitterroot Valley. In 1996, three packs produced 11 pups.

In the winter of 1996, 17 wolves were captured near Fort St. Johns, British Columbia, Canada and were again released into acclimation pens in Yellowstone National Park. Twenty wolves were released in central Idaho. These translocated wolves were the same subspecies that existed in the northern Rocky Mountains historically.

Wolves were not released within Montana, but wolf populations in Yellowstone National Park and central Idaho grew rapidly and soon became a source for dispersers to Montana. New packs formed outside the earliest core wolf areas and overall wolf distribution expanded. Wolf dispersal has been documented between and among all three federal recovery areas and the states comprising the northern Rockies.

By the end of 2002, the northern Rockies wolf population met the biological recovery criteria of at least 30 breeding pairs in the northern Rockies for three years in a row. By the end of 2004, there was an estimated 835 wolves and 66 breeding pairs in the tri-state area. In Montana, there were about 153 wolves in 15 breeding pairs at that time.

Wolf populations in the Northern Rocky Mountains continued to expand and reached recovery goals. With the exception of Wyoming, they were delisted in 2011, giving management authority to the states. The five-year federal oversight period for Idaho and Montana ended in 2015 and wolf populations remained well above minimum federal management objectives of 15 breeding pairs and 150 wolves in each state.

Management
While Idaho has full authority to manage wolves in the state, federal regulations continue to guide management practices. To remain in compliance with federal law, IDFG’s conservation and management program aims to maintain the overall population high enough to prevent its reclassification as threatened or endangered under the Endangered Species Act.

Idaho Fish and Game is the lead agency for Gray Wolves, including population monitoring, resolving wolf-livestock conflicts, research, and public outreach. Federal regulations continue to guide management practices.

Distribution and Status
Wolves occur throughout Idaho. They are managed and protected by regulated harvest seasons.