Marmots may live to 5 years or more. They feed on grasses, flowering plants, berries, roots, mosses, and lichens. Hoary and Alaska marmots make their summer homes on the bases of active talus slopes, where the rocks protect them from predators and provide lookout stations. Woodchuck dens may be up to 30 feet long, are dug in the loamy soils of river valleys in Interior Alaska, and end with a chamber containing a large grass nest. Most marmot dens have a main entrance with a mound of dirt near the hole and a number of concealed entrances.
Marmots are social animals.
Although each family has a separate burrow, these burrows are located near each other, forming a colony. True hibernators, marmots enter a state of torpor in winter during which all bodily functions are reduced. Hoary marmots and woodchucks hibernate alone in the same burrows in which they spent the summer. To protect themselves from the cold, they plug the tunnel leading to the nest chamber with a mixture of dirt, vegetation, and feces. They emerge from their winter hibernation in April or early May to find food and mates.