Arctic Ground Squirrel Fact Sheet
Scientific and common names
Spermophilus parryii - Arctic Ground Squirrel
General Description
Arctic ground squirrels are the largest of all ground squirrels in North America, ranging 13-19.5 inches in length and 1.1-3.3 pounds, with males larger than females. They are tawny brown in color, with white flecks on the dorsal (back) side and light tan or beige on their undersides. In the winter, their undersides lighten up. Their bodies are cylindrical in shape, with short but strong forearms and hind legs, and sharp claws making them built for burrowing and digging. Their heads and ears are rounded, and their tails are relatively short compared to other squirrel species. Click here to hear what they sound like.
Range
The arctic ground squirrel is the only species of ground squirrel in Alaska, where they can be found across northern, eastern, and southwestern Alaska at elevations ranging from sea level to well above mountain tree lines. They inhabit tundra, meadow, riverbank, and lakeshore habitats with loose soils that provide early vegetation. They sometimes den in soft sandy soils along the coast where they may drown in unusually high fall storm surges or easily be dug up for a grizzly’s meal.
Life History
Arctic ground squirrels live on average 8–10 years. For about eight months of the year, arctic ground squirrels hibernate to cope with the harsh winter conditions. They prefer hibernacula covered by vegetation which keeps their dens warmer during winter. Females begin hibernating in August, with males following over the next month. Males emerge from hibernation about 3 weeks earlier than females in order to reach sexual maturation. During hibernation, they enter into a state of torpor, in which their metabolic rate and body temperatures drastically drop for up to 3 weeks at a time. Body temperatures drop from about 99 degrees F to as cold as 27 degrees F. Between these states of torpor they arouse for 1-2 days to raise their body temperature back up to the mid 90os. By the time they emerge from hibernation, arctic ground squirrels will have lost approximately 1/3 of their body weight, with females losing more weight than males.
Mating season begins in late April to early May, after squirrels emerge from hibernation. Arctic ground squirrels have a polygynous mating system, where males aggressively defend territories with multiple females. Males looking for new territory or to expand their range may engage in infanticide. After breeding, females group together in kin clusters, possibly to protect against infanticidal males and other predators. The aggressive, territorial behavior of males takes its toll on their bodies, resulting in loss of body mass, compromised immune systems, and death. After mating season there are more females than males. After a gestation period of 25-30 days, females give birth to a litter of 2-10 young. At birth, offspring are blind, hairless, and toothless, but grow rapidly for the first few weeks, and by age 8-10 weeks, the young disperse from the den, and are sexually mature by the following spring.
Diet
Arctic ground squirrels are highly opportunistic feeders and feed on vegetation such as stems and leaves, roots, fruits, seeds, flowers, grasses and sedges, and other green or woody plants, as well as mushrooms. They are also known to eat eggs, invertebrates, and small vertebrates including juvenile snowshoe hares, collared lemmings, and even their own young. Food is stored or cached only by male arctic ground squirrels in burrows for arousal from winter hibernation.
Threats/Concerns
The biggest concerns for arctic ground squirrels are their myriad of predators, including golden eagles, gyrfalcon, rough-legged hawk, ermine, wolves, arctic fox, grizzly bear, and humans who hunt them or destroy their habitat.
Fun Facts
There are three types of squirrels in Alaska: Arctic ground squirrels, flying squirrels, and red squirrels. Only the arctic ground squirrels hibernate in winter.
Male arctic ground squirrels are highly territorial and often exhibit infanticide toward non-related offspring.
Arctic ground squirrels are members of the family Sciuridae, which includes marmots, chipmunks, prairie dogs and squirrels.
Arctic ground squirrels show how human modifications to the landscape can alter the range of wild animals, as they are now commonly found along the road system where they construct burrows in the loosened ground along the shoulders of roads.
Researchers studying human ailments linked to body clock disruptions (such as seasonal affective disorder, obesity, cardiovascular disease, Alzheimer's, even cancer) and studying Arctic ground squirrels to determine how they finely tune their body rhythms.
The Arctic ground squirrel has developed highly specialized adaptations to extreme environments, and it has a lot to teach us about circadian rhythms and biological clocks. This species maintains circadian rhythms throughout the Arctic summer, despite the almost ceaseless daylight during this period. The squirrels' body clocks have evolved to work just fine without the help of the day/night cycle, which is so important to other animals--like humans.
Print the coloring sheet below to make your Arctic ground squirrel come to life!
Information consolidated, in part, from Alaska Department of Fish and Game
