If danger approaches, they pass the warning whistle along the valley and those feeding or sunning on a rock will gallop for home. They also take note of the alarm calls of some of their lesser neighbors such as pikas and ground squirrels. Their predators include grizzly and black bears, wolves and wolverines, and golden eagles which are likely their main predator. Diurnal in activity, hoary mnarrnots spend about eight months of each year in a kind of hibernation. It is not actual hibernation but a lethargic, torpid state, during which breathing, pulse rate and body temperature are only slightly depressed.
Marmots probably mate as soon as they emerge from their burrows.
The young are born toward the end of May or in early June. Litters of four or five seem to be the average. As grazing animals they eat a large variety of green alpine grasses and forbs. The area around marmots' dens often appears heavily grazed and they may travel several hundred yards to feed. The marmot occupies a beautiful alpine niche in the wilderness, along with Dall sheep, caribou and many other kinds of smaller mammals.