Washington's Endemic Mammal: The Olympic Marmot

Endemic species are those that are native to a specific area and are only found (in the wild, at least) in that specific area. Mountains, islands, and other such area often have endemic species due to their isolation. The Olympic National Park is host to a number of these species, many of which even have “Olympic” or “Olympus” somewhere in their name (National Park Service 2015).

The Olympic marmot (Marmota olympus) is one of these species. They are only found in the Olympic Peninsula and 90% of them are located within the boundaries of the Olympic National Park. Of the six marmot species found in North America, Olympic marmots are the second-rarest after the critically endangered Vancouver Island marmot. Their population is estimated to be between 2,000-4,000 individuals (Cassola 2016).

Olympic marmots are members of the squirrel family (Sciuridae). They are about the size of a domestic cat with wide faces, stocky bodies, bushy tails, and large claws for digging. They weigh between 6.0 to 24.3 pounds (2.7 to 11 kg) and are from 26 to 30 inches (67 to 75 cm) in length. They are the largest North American marmot species and have the most pronounced sexual dimorphism of any marmot species in the world with males being up to 25% larger than females.

The pelt color of these marmots change throughout the year. Overall, they are brown in color with white patches such as the muzzle and between the eyes. When they emerge from hibernation, their pelts can be tan or yellow in color. In June, they undergo a molting period which ends with two black patches forming on the shoulders. They darken over the course of the summer and in the fall they can be close to black in color (Barash 1989). Pups are born with grey fur that turns brown as they mature.

Olympic marmots hibernate between September and May for the adults and June for the youth. They are deep hibernators, warming themselves every ten days or so, but otherwise remaining inactive (National Park Service 2019). They do not store food for the winter and instead can double their body weight to last them through the eight month hibernation period. Females only start this process after their young are weaned, which can result in their going into hibernation later in the fall and at a lower body weight than non-reproductive females (Griffin, Taper and Mills 2007).

Mating occurs soon after they emerge from hibernation. The male typically mates with one female one year and the other female the next. After a four-week gestation period, the female gives birth to a litter of about four to five pups. The pups stay with their parents for about two years. Females are typically two or three years old when they have their first litter and have one litter every other year, though studies suggest they can reproduce more frequently if they have sufficient food supply in the spring (Griffin, Taper and Mills 2007).

Typically, Olympic marmots live in alpine meadows about 4,000 feet above sea level. Sometimes they can be found closer to sea level, but this is rare. They feed on heather, lupine, grasses, sedges, and mosses. They’ll eat roots when they first emerge from hibernation when their typical diet has not appeared yet. Occasionally, they will feed on insects.

Olympic marmots are quite social. They live in colonies consisting of one male, two or three females, a new litter, and a litter of one-year-old marmots from the previous year. These colonies consist of multiple burrows. A “satellite” male might live in a nearby burrow and take over when the “colony” male dies (Barash 1989).

They greet each other by touching noses or cheeks and often play fight. They have four types of alarm calls: ascending, descending, flat, and trills. They give one of these calls when a threat is near. In areas where humans frequent, marmots may not give out an alarm call. In fact, marmots adapt quickly to the presence of humans and will allow them near colonies without much resistance.

Despite their low numbers and susceptibility to climate change, Olympic marmots are regarded as being of least concern by the International Union for Conservation of Nature due to their habitat being located almost entirely within the Olympic National Park: a UNESCO International Biosphere Reserve and World Heritage Site (Cassola 2016). They are also protected by state law, which prevents humans from hunting them. However, human recreation activities are the biggest threat to marmots.

Another prominent threat to Olympic marmots are coyotes. According to a report by the National Park Service, during the period 2002-2006, predation by coyotes was the most common cause of death for adult female marmots and analysis of coyote scat throughout the Olympic National Park indicated that marmots could constitute as much as 20% of coyotes’ summer diet (National Park Service 2019). As coyotes were not present in Olympic marmots’ habitat prior to the 20^th century, it has been suggested that climate change could be the reason why coyotes are now such a threat. Less snowpack makes alpine meadows a more desirable habitat for coyotes.

The Olympic marmot became a state symbol thanks to the efforts of 4^th and 5^th grade students at Seattle’s Wedgwood Elementary School. Through emails and visits to the state capital, the students successfully lobbied state legislature into supporting their bill, which was officially designated in 2009. The hope in denoting the Olympic marmot as the state endemic mammal was to bring greater awareness of the species (S. 5071.SL).

If you want to try spotting them in the wild, they are often found at Hurricane Ridge during the summer. Just be sure to keep your distance and don’t feed them. You can also volunteer to be a marmot monitor (for more information, visit https://www.nps.gov/olym/getinvolved/olympic-marmot-monitoring.htm) and help the Olympic National Park collect up-to-date population data.

References

Barash, D. P. (1989). Marmots: Social behavior and ecology. Stanford, CA: Stanford University Press.

Cassola, F. (2016). Marmota olympus. Retrieved December 29, 2020, from https://www.iucnredlist.org/species/42459/22257452

Griffin, S. C., Taper, M., & Mills, L. (2007). Female Olympic Marmots (Marmota olympus) Reproduce in Consecutive Years. The American Midland Naturalist, 158(1), 221-225. Retrieved January 2, 2021, from http://www.jstor.org/stable/4500650

National Park Service. (2015). Endemic Animals of the Olympic Peninsula. Retrieved January 01, 2021, from https://www.nps.gov/olym/learn/nature/endemic-animals.htm

National Park Service. (2019). The Olympic Marmot: Ecology and Research. Retrieved January 01, 2021, from https://www.nps.gov/olym/learn/nature/loader.cfm?csModule=security%2Fgetfile

S. 5071.SL, 61st Legislature Cong. (2009) (enacted). Retrieved December 30, 2020, from http://lawfilesext.leg.wa.gov/biennium/2009-10/Pdf/Bills/Session%20Laws/Senate/5071.SL.pdf?cite=2009%20c%20464%20%C2%A7%202

© Laura Caldwell, January 2021