Nature On Trail: Marmots
By Pam Roy
“ Hey, get outta my pack!”
Our trail crew was carrying 50-pound bags of topsoil up the slopes above Paradise at Mount Rainier on a revegetation project. A couple of plump, persistent marmots—seemingly unappreciative of our work to restore their natural food source—were raiding our backpacks.
Marmota caligata, commonly known as the hoary marmot, lives in some pretty scenic neighborhoods. The namesake silvery grey fur on their shoulders and backs helps them blend in with the talus slopes or rocky outcroppings near treeline. Feet and legs are black, the belly whitish. Reaching 27-32 inches long, with a reddish-brown bushy tail, they weigh 11-15 pounds. While volunteering at Mount Rainier, I’ve had visitors excitedly ask me about the “little bear” they saw, showing me a picture of a marmot. The hoary marmot ranges from northern Alaska through the Cascades and Rocky Mountains to Montana and central Idaho.
Small mounds of soil may indicate the entry to a marmot den, which are burrowed up to six feet underground and usually have several entrances. The nest den may be lined with grasses. Marmots are social animals; they live in colonies. Families of up to fifteen may snuggle together in the den to keep warm during hibernation (late September to April). Being diurnal, they emerge from the den on warm, sunny days, preferring to spend windy, wet or snowy days inside.
Most hikers have heard the piercing shrill whistle of the sentinel marmot keeping an eye out for intruders. This whistle alarm gives them the nickname “whistle pig.” Different calls indicate differing levels of urgency or the presence of predators, including foxes, coyotes, golden eagles hawks or bears. Marmots in areas seldom visited by people will retreat to safety once the alarm is sounded. Those habituated to the presence of humans may stand up on their hind legs to keep an eye on the passing hiker, or even beg for food. As with any wildlife, they should not be fed.
Mating occurs in spring. Couples may court by making mewing sounds or play-wrestling and showing their teeth. Litters are born a month later; the babies are blind and have no fur. The colony of “aunts and uncles” help keep an eye on the young once they emerge from the den. Adults take turns as the sentinel guard, perching on prominent rocks. Males may have more than one mate as the stress of providing nutrition for a litter for an entire season can make a female incapable of having a litter the following spring.
By the time fall arrives, these critters have put on a lot of fat, perhaps half their body weight. The vegetation near their burrows may appear clipped almost like a lawn. An individual marmot may chase others away from areas it considers its food source.
Two other species of marmots are found in Washington. The Olympic marmot (Marmota Olympus) is found only on the Olympic peninsula. The yellow-bellied marmot (Marmota flaviventris) has a range that overlaps with the hoary marmot, but these animals tend to live at lower elevations.
Marmots spend their days voraciously feeding on sedges and broadleaf alpine greenery, passing lazy afternoons draped over sun-warmed rocks or playing tag and wrestling in the meadows. What a life!