Yellow-bellied Marmot

Basic Facts & Names

The scientific name flaviventris means “yellow belly” (from Latin flavus = yellow, ventris = belly).

Common names include yellow-bellied marmot, rockchuck, and whistle-pig.

Despite some confusion in colloquial use, it is incorrect to call all marmots “woodchucks” (a woodchuck is a different species).

Marmots are large, heavy-bodied rodents with sturdy limbs, small eyes, and rounded ears.

They have a slightly flattened tail, covered densely with fur, measuring about 5–7 inches.

Total body length ranges from 19 to 27 inches (≈ 48 to 69 cm) including tail.

Weight: typically between 4 and 12 lbs (≈ 1.8 to 5.4 kg) depending on sex, age, and season.

Habitat: they prefer rocky terrain—cliffs, rock slides, talus, cliffs or boulder fields—with nearby grassy meadows for feeding.

They often locate burrows beneath rocks, using rock walls or slabs to support their dens and provide lookout perches.

Activity: marmots spend limited time above ground—typically in the midmorning and late afternoon—to feed or sun themselves.

They are true hibernators: in early fall they retreat into their burrows and remain underground until spring.

They feed on a variety of grasses, forbs, and flower seeds in meadows close to their burrows.

Marmots typically do not breed until about 2 years old.

A female will bear a litter of 4-6 young every other year (i.e. not annually).

Predators include coyotes, foxes, bobcats, mountain lions, and raptors like golden eagles.