Marmota flaviventris

The coarse-looking upper body pelage is yellow-brown to tawny, often with a frosted appearance, and with a buffy band on the side of the neck. Most have a whitish band across the snout. The tail is short and bushy. Total length reaches about 68 cm.

Yellow-bellied marmots occupy alpine tundra, subalpine and montane meadows, and foothills and canyons at lower elevations. They are semifossorial; individuals use one or more burrows; may share hibernation burrow. Burrows open under rocks (or logs or bushes) in areas of well-drained talus, rock outcrops, or scattered boulders. Habitat sizes range from 0.01 to 70 ha or more (Armitage 1991). Young are born in underground burrows.

Yellow-bellied marmot communication includes auditory and chemical signals. They express alarm, alertness, or threats through whistles. They use their cheek glands to leave scent marks that may help convey social status.

These marmots live alone, in pairs, or colonies. Colonies typically consist of one or more adult territorial males, 1-5 adult females and their young (usually including yearlings and younger offspring). Small habitat patches may include a female and her offspring but adult males and yearlings may not be present (Armitage 1991).

May harbor fleas that are vectors of sylvatic plague or tick that transmits Rocky Mountain spotted fever.

Mating typically occurs shortly after emergence from hibernation. Gestation lasts about 30 days. Litters vary in size between 3-8 young/year. Young remain in burrow for 20-30 days (Frase and Hoffmann 1980), emerge from the natal burrow in late June or July in the mountains of western Colorado, but range-wide reproductive timing varies with elevation and the timing of snow melt. At the highest elevations, females rarely produce litters in consecutive years (Armitage 1991). Males typically first breed at age three or older (Armitage 1991).