Marmota flaviventris
(Yellow-bellied Marmot)

Order: Rodentia
Order Description:Rodents
Family: Sciuridae
Family Description: Chipmunks, Marmots and Squirrels

This large, heavily bodied rodent is reddish-brown dorsally, often having a slightly frosted appearance due to light tipped hairs. Its belly is yellowish. It has small fur,covered ears and a prominent, erect tail. Total length is 20 - 28 inches (500 - 700 mm), tail length is 5 1/8 to 8 ¾ inches (130-220 mm), they weigh 3.5 - 11 pounds (1.6-5 kilograms). melanisticClick word for definition forms appear in various local populations of Idaho. Early settlers in Idaho called the marmot "whistle pigs", perhaps a good name since this marmot is fat appearing and it spends considerable time basking in the sun. If danger appears, however, it gives a shrill whistle as an alarm call. Many Idahoans also call them "rockchucks", a common name probably derived from the eastern "woodchuck" or "groundhog".

From south-central British Columbia and southern Alberta, south to southern California and northern New Mexico.

Found (typically above 2000 m) in meadows, valleys, and foothills, often in open areas where forest and meadow form a mosaic. In Idaho, prefers talusClick word for definition slopes, rocky outcroppings and rimrock.

Feeds on wide variety of grasses and forbsClick word for definition.

At higher elevations, marmots may hibernateClick word for definition from early September to May; at lower elevations they emerge late February to mid-March. In more boreal zones, they may be active all summer, but begin aestivation in June at lower elevations. They burrow under rocks, logs, or bushes in areas of well-drained talus, rock outcrops, or scattered boulders. Their burrows may be up to 15 feet long and provide protection against predators, extremely high summer temperatures and cold temperatures during hibernationClick word for definition. The area over which they range varies from about 2.5 acres to 155 acres (1 ha to 70 or more). While they are social mammals, they occasionally live alone, but usually in pairs, or colonies. A colony typically consists of 1 or more adult territorial males and 1 to 5 adult females and their young. Most colonies do not exceed 1 male and 3 females. Small habitat patches may include a female and offspring, but adult males and yearlings may not be present. Virtually all males and slightly less than half of the females disperse from their natal colony, typically as yearlingsClick word for definition. dispersalClick word for definition distance usually is less than 2.5 but up to 10 miles (4-15.5 km) for males, and 4 miles (6.4 km) for females. They may harbor fleas that are vectorsClick word for definition of plague or ticks which transmit Rocky Mountain spotted feverClick word for definition. A primary mortalityClick word for definition factor is hibernation and they are preyed on by larger predators such as golden eagles, coyotes, cougars and others.

Mating usually occurs within 2 wk after hibernation. GestationClick word for definition lasts about 30 days. litterClick word for definition varies between 3-8 young/yr. Young remain in burrow for 20-30 days, and emerge in late June to mid-July (Colorado). At highest elevations, females rarely produce litters in consecutive years. Males typically first breed at age 3 or older.

Status: Unprotected nongame species

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Information written by Donald Streubel,© 2000
Map image provided by
Stephen Burton,© 2000
Design by Ean Harker©1999, 2000.