By Arthur Cooper
Geographic Range
Olympic marmots inhabit the Olympic Peninsula in the western section of the state of Washington in northwestern United States. (Grzimek, 1988)
Habitat
(5248 ft)
Alpine meadows and slopes at elevations above 4800 feet are inhabited by Olympic marmots. They tend to favor slopes that are rocky and face south. (Grzimek, 1988; Van Gelder, 1982)
These animals are found in the following types of habitat:
temperate 
; terrestrial .
Terrestrial Biomes:
mountains .
Physical Description
(6.6 to 19.8 lbs; avg. 13.2 lbs)
The head and body length of Olympic marmots is from 46-53 cm and the tail is 18-25 cm long (Burt 1976). The legs are 9.4-11.2 cm in length (Hall & Kelson 1959). Olympic marmots have a stocky appearance, with large shoulders and a wide head (Grzimek 1988). Large, rounded claws are used for digging. The hair is brown with white intermixed for much of the year, but changes to a yellowish color in the summer due to sun bleaching (Nowak 1999). (Burt, 1976; Grzimek, 1988; Hall and Kelson, 1959; Nowak, 1999)
Some key physical features:
endothermic ; heterothermic ; bilateral symmetry .
Reproduction
Females breed every two years.
Mating occurs within a few weeks after emerging from hibernation.
Male Olympic marmots have a harem of two females.
Mating systems:
polygynous .
Due to harsh environmental conditions, the estrus cycle occurs every two years in order to allow females to recuperate from raising a litter. The estrus cycles of the two females in the harem are usually alternated so that there is only female reproducing each year (Grzimek 1988). Mating occurs about two weeks after hibernation ends (Van Gelder 1982). Gestation lasts 30-32 days and young are born in a burrow padded with grass. The litter size is usually 4-5 offspring. The offspring are sexually mature at the age of three (Nowak 1999).
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Behavior
Olympic marmots are highly social and may live in groups of over a dozen animals. These groups usually include an adult male, two adult females, yearling offspring, and newborn offspring. Gregarious bonds are made between individuals in a family. Olympic marmots identify each other by touching noses and smelling of cheeks. This behavior, along with grooming, establishes the standing of each individual in the family. Little contact occurs with a neighboring group, though a border may be shared. Olympic marmots are diurnal and terrestrial animals. During the morning and afternoon on summer days, they feed and spend time sunbathing on rocks. In the evening, they return to their burrows. Well used trails connect their burrows. A mother and her offspring generally live in their own burrow. Adult males usually inhabit a burrow with one or two females. During hibernation, which lasts 3-9 months, all marmots in the group stay in the same burrow. (Grzimek, 1988; Nowak, 1999; Van Gelder, 1982)
Food Habits
Olympic marmots eat herbs, grasses, and flowers. They prefer plants that are soft and easy to digest. They may also eat fruits, legumes, and insects. After coming out of hibernation, roots are the only source of food until vegetation growth begins. (Grzimek, 1988; Nowak, 1999)
Plant Foods:
leaves; roots and tubers; flowers.
Economic Importance for Humans: Negative
There are no adverse effects of Olympic marmots on humans.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Olympic marmots are not currently considered endangered.
For More Information
Find Marmota olympus information at
Contributors
Arthur Cooper (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.
