The Hoary marmot (Marmota caligata) is a species of marmot that lives the mountains of northwest North America. 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 after these animals to help make it more marketable as a resort.
The Hoary marmot is a large, bulky, ground squirrel, with short, heavy limbs, and a broad head. The word "hoary" refers to the silver-gray fur on their shoulders and upper back; the remainder of the upper parts have drab- or reddish-brown fur. The head is black on the upper surface, with a white patch on the muzzle, white fur on the chin and around the lips, and grizzled black or brown fur elsewhere. The feet and lower legs are black, sometimes with white patches on the fore feet. Marmots have long guard hairs that provide most of the visible color of their pelage, and a dense, soft underfur that provides insulation. The greyish underparts of the body lack this underfur and are more sparsely-haired than the rest of the body. Hoary marmots molt in the early to mid-summer. The feet have slightly curved claws, which are somewhat larger on the fore feet than on the hind feet. The feet have hairless pads, enhancing their grip. The tail is long, slightly flattened, and covered with dense fur. Apart from the larger size of the males, both sexes have a similar appearance. Females have five pairs of teats, running from the pectoral to the inguinal regions. Males of this species are significantly larger than females.
Hoary marmots are found in northwest North America. They occur from southern Washington and central Idaho north and are found through much of Alaska south of the Yukon River. These animals inhabit mainly mountainous alpine environments, in rocky terrain or alpine meadows dominated by grasses, sedges, herbs, and Krummholz forest patches.
Hoary marmots are diurnal being active during the day. They live in colonies of up to 36 individuals. Each colony includes a single, dominant male, up to 3 females, sometimes with a subordinate adult male, and a number of young and subadults up to 2 years of age. Hoary marmots hibernate 7-8 months a year in burrows they excavate in the soil, often among or under boulders. Each colony typically maintains a single burrow for hibernation and a number of smaller burrows that they use for sleeping and refuge from predators. Each colony digs an average of 5 such burrows a year, and a mature colony may have over a hundred. Closer to hibernation time Hoary marmots like to socialize through play fighting, wrestling, social grooming, and nose-to-nose touching. These animals use at least seven distinct types of calls, including chirps, whistles, growls, and whining sounds. Many of these calls are used as alarms, alerting other animals to potential predators.
Hoary marmots are herbivores (folivores). They feed on leaves, flowers, grasses, mosses, lichens, and sedges.
Hoary marmots are usually monogamous, mating with the same partner more than once. However, southern populations are suggested to be both monogamous and polygynous. These marmots breed shortly after hibernation in May and in some areas (such as the eastern Cascade foothills of Washington State) as early as February. Females give birth to 2-5 young between late May and mid-June. The gestation period usually lasts 25 to 30 days. The young emerge from their birth den at 3-4 weeks of age, by which time they are fully furred and are already beginning to be weaned. Subadults remain with their birth colony but typically leave at 2 years of age. They reach reproductive maturity the following year.
There are no major threats to Hoary marmots at present.
According to IUCN, the Hoary marmot is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
