Olympic marmot
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Sciuridae
Genus:	Marmota
Subgenus:	Petromarmota
Species:	M. olympus
Binomial name
Marmota olympus (Merriam, 1898)
Range of Olympic Marmots

The Olympic marmot, Marmota olympus, is a rodent in the squirrel family, Sciuridae. They are close relatives of the hoary marmot. This species is exclusively indigenous to alpine and subalpine meadows and talus slopes on the Olympic Peninsula in the U.S. state of Washington. For this reason, the Olympic marmot was declared Washington's state endemic mammal in 2009.^[2]

This species was first regarded as a subspecies of M. marmota by Clinton Hart Merriam, an American entomologist, ethnographer, ornithologist, and zoologist, in 1898.^[3] It was later described as the distinct species, Marmota olympus, by taxonomists such as Jones in 1992, Hoffman in 1993, and Thorington in 2005.^[1]

This rodent is about the size of a house cat, often weighing more than 15 pounds after gaining weight to prepare for hibernation in September and early October. Most of the year this marmot's fur is brown with white areas, developing lighter brown patches during the summer, but it varies throughout the year. In the fall, their fur is almost black, but after surfacing from hibernation in the spring they can be tan or even yellowish in color.^[4] Its muzzle is almost always white along with a white band in front of the eyes, and Olympic marmot's tails are long and bushy.^[5] Both its eyes and ears are small, along with short, stubby legs and sharp claws that aid them when digging their burrows.^[6] An important difference between the this marmot and the hoary marmot is that the hoary marmot isn't as brown as the Olympic marmot, although they share almost every other physical trait.^[7]

Female Olympic marmots have a litter of between 3 to 6 in alternate years. The young do not reach sexual maturity until their third year, perhaps because of the short growing season.

About 4 weeks after mating a female Olympic marmot gives birth in a grass-lined burrow underground. The pups cannot see, they have no fur, and they are pink in color when they are first born. ^[8]

Like most marmots, Olympic marmots are gregarious burrowing animals. A typical family consists of a male, two to three females and their young. Newborn marmots stay with their family for at least two years so a burrow will usually be home to a newly born litter and a year old litter. Olympic marmots hibernate from September through May. This is the most dangerous time for the Olympic marmot and in years of light snowfall as much as 50% of the young born in that year will perish.^[9] Prior to hibernation, the marmots bring dry grasses into the burrow for bedding or food. To greet each other, the marmots touch noses. During more extended greetings, they may touch nose to cheek and nibble on each others' ears and neck. They may also engage in play fighting in which two marmots on their hind legs push each other with their paws. The play fighting is more aggressive between older marmots.

After they come out of hibernation, their diet consists largely of roots until new vegetation appears in the spring, after which they feed on grasses, herbs, mosses and flowers as well as the occasional insect. During the active months of June, July, and August, the marmots forage in the morning and afternoon with a break around midday. Before each feeding period they visit the other burrows in the colony, which are frequently found on southern-facing slopes as the snowmelt from earlier in the year leads to more food.

Olympic marmots, like all other marmots, have a variety of distinctive calls or whistles which alert other marmots to predators. There are four basic calls: ascending, descending, flat and trills. The first three calls are distinguished by relative frequency of their starting and ending pitch. The trills are a series of ascending calls in rapid succession and are the most rare, being reserved for situations of great danger. The flat calls are the most common. The calls can be heard here. Common predators of the Olympic marmot are the coyote and puma although the marmots have been observed making alarm calls for a number of large birds of prey as well as bears and bobcats.

Olympic marmots are relatively easy to see on the very accessible Hurricane Ridge in Olympic National Park where they are quite numerous. Olympic marmots are in decline in some areas in the park. This is believed to be due to the encroachment of trees into the meadows as well as predation by coyotes. Olympic marmots are a protected species in Washington. In 2009, legislation was signed that declared the Olympic marmot to be Washington State's official endemic mammal.