The hoary marmot (Marmota caligata) is a species of marmot that inhabits the mountains of northwest North America. The largest populations are in Alaska. In the northern part of that state they may live near sea level. Hoary marmots live near the tree line on slopes with grasses and forbs to eat and rocky areas for cover. It is the largest North American ground squirrel and is often nicknamed "the whistler" for its high-pitched warning issued to alert other members of the colony to possible danger. The animals are sometimes called "whistle pigs." Whistler, British Columbia, originally London Mountain because of its heavy fogs and rain, was renamed for these animals to help make it more marketable as a resort.
The "hoary" in their name refers to the silver-grey fur on their shoulders and upper back; the remainder of the upper parts are mainly covered in reddish brown fur. The underparts are greyish. They have a white patch on the muzzle and black feet and lower legs.
These animals hibernate 7 to 8 months a year in burrows that they excavate in the soil, often among or under boulders. Mating occurs after hibernation and 2 to 4 young are born in the spring. Males establish "harems," but may also visit females in other territories. Predators include golden eagles; grizzly and black bears; and wolves.
Unlike most animals their size, hoary marmots are not shy around humans. Rather than running away at first sight, they will often go about their business while being watched.