The Hoary Marmot, the largest of the North American sciurid rodents, is a fascinating, charismatic animal. Marmot population biology, their impact on the ecosystem, physiology and behavior is studied worldwide. The only holiday in the United States to be named after an animal is named for a marmot - Groundhog's Day. Closely related to tree squirrels, prairie dogs, and groundhogs, hoary marmots are the largest ground-dwelling squirrels in the world.
Sociable, communicative and entertaining to observe, marmots often grow to the size of a large domestic house cat. Although there are 14 marmot species worldwide, only two inhabit Montana - the hoary and the yellow-bellied marmot. Denning in rocky outcroppings, the hoary marmot is normally found in high alpine meadows and sub-alpine mountain slopes. Weighing up to 20 pounds, the hoary marmot is one of the largest rodent species in North America. The smaller yellow-bellied marmot builds dens at lower elevations and weighs about 10 pounds. In several parts of the world marmot meat is considered a prized delicacy and their fur is highly valued.
Marmots are normally found living in small family groups; one breeding male, multiple breeding females and their non-breeding offspring from previous years. A colony of 15 to 20 will live together in a system of burrows and hibernate together all winter. The range of a marmot colony is rather extensive and may cover several acres. The marmots roam freely and will cover most of their territory daily.
Marmot dens are usually found under large rocks or boulders which prevents a predator from digging them up and protects them from the elements. Marmot predators include the wolf, cougar, coyote, fox, owl, and eagle.
Considered by many to be rat-like rodents, marmot colonies are often used for target practice, the carcasses left in the open to be devoured by the ravens. Similar to a prairie dog town, a marmot colony is destructive to a meadow and many ranchers attempt to eliminate the colony when the marmots intrude on private lands
Marmot colonies are highly interactive and extremely vocal. Their trilling is an eerie sound. Early settlers called them "whistlers" because they emit a loud, piercing trill or whistle to alert the colony of danger. They seem to have several different alert signals, varying in pitch and intensity. "Heads Up - Here Comes A Bear" probably warrants the most attention. Marmots are important food to both grizzly and black bears.
When they are not sunning themselves on lookout rocks, marmots are usually foraging for tasty vegetation, munching on lichen, leaves, flowers, roots, seeds, and berries. A marmot's primary diet is vegetarian, however; they will occasionally snack on insects or roadkill.
Relying on accumulated fat deposits, marmots hibernate through the hard cold of Montana winters. Depending on their location and the severity of the winter, marmots will hibernate from October through May.
Marmots normally have litters of three to five pups. The marmots of Montana, and all other members of the genus Marmota, have thick, slightly curved claws. Equipped for digging, the claws are considerably heavier on the front feet than they are on the hind legs. Marmot palms are hairless with five pads, their smooth soles are also naked but have six pads.
Often described as "cute", marmots have small, circular eyes and rounded short, hairy ears. With their pelage, nature has provided perfect camouflage. The hoary marmots' common name refers to its colorization which is an "icy" silver-gray. The front half of the marmot's back is normally black hair with white tips, the remainder of the back coat is dark brown. Cinnamon or brown heads tinged with a snow-white mustache give the marmot a comical expression.
Hoary and yellow-bellied marmots leave a lasting impression and are a welcome addition to Montana's wildlife heritage.