Subspecies
Listed alphabetically.[2]
- S. p. ablusus Osgood, 1903
- S. p. kennicottii Ross, 1861 "? Barrow ground squirrel (northern Alaska, northern Yukon, and northern Northwest Territories)
- S. p. kodiacensis Ross, 1861
- S. p. leucostictus Brandt, 1844
- S. p. lyratus Hall and Gilmore, 1932
- S. p. nebulicola Osgood, 1903
- S. p. osgoodi Merriam, 1900
- S. p. parryii Richardson, 1825
- S. p. plesius Osgood, 1900
- S. p. stejnegeri J. A. Allen, 1903
Background
20,000 year old Arctic ground squirrel mummy
The diurnal Arctic ground squirrel lives in colonies and is prey to the Arctic Fox, wolverine, lynx, the Grizzly Bear, and eagles. It is one of the few Arctic animals, along with their close relatives the marmots[3] and the un-related little brown bat that hibernate.[4] In the summer it forages for tundra plants, seeds, and fruit to increase body fat for its winter hibernation. By late summer it begins to store food in its burrow so that in the spring[5] it will have edible food until the new vegetation has grown. The burrows are lined with lichens, leaves and muskox hair.
During hibernation, its brain and core temperature can drop to just above freezing and its heartbeat drops. Peripheral, colonic, and blood temperatures become subzero by means of supercooling. Body temperatures drop as low as ?2.9 °C (26.8 °F) (average ?3 °C (27 °F)), the lowest known naturally occurring core body temperature in mammals.[6][7]
Geographic range
The Arctic ground squirrel can be found in regions of Northern Canada ranging from the Arctic Circle to northern British Columbia, and down to the southern border of the Northwest Territories, as well as Alaska and Siberia.[1]
Habitat
The Arctic ground squirrel inhabits dry Arctic tundra and open meadows in the most southern habitats of this species.[8]
On tundra, Kugluktuk, Nunavut
Physical description
The Arctic ground squirrel has a beige and tan coat with a white-spotted back. This squirrel has a short face, small ears, a dark tail and white markings around its eyes. The average length of an Arctic ground squirrel is approximately 39 cm (15 in), and the average mass 750 g (26 oz), however, males generally are around 100 g (3.5 oz) heavier than females.[8]
Reproduction
Arctic ground squirrels live in colonies dominated by one male. Mating occurs in mid May after winter hibernation. Gestation is approximately 25 days, and results in a litter of 5 to 10, 10 g (0.35 oz) hairless pups. After 6 weeks the pups are weaned and this is followed by rapid growth to prepare for the upcoming winter.[8]
Behaviour
The Arctic ground squirrel hibernates over winter from early September to late April, at which time it can reduce its body temperatures from 37 °C (99 °F) to as little as ?3 °C (27 °F).[6] In the warmer months, the squirrel is active during the day time.
Communication between squirrels is done through both vocal and physical means. When they meet, nose to nose contact is made or other body parts are pressed together. The "tsik-tsik" calls are made in response to threats and vary as between different predators. Deep guttural sounds are used to indicate land-based predators while short "band whistle" chatter indicates danger from the air.[8]
Food habits
This squirrel feeds on grasses, sedges, mushrooms, bog rushes, bilberries, willows, roots, stalks, leaves, flowers, and seeds. Sometimes this squirrel carries food back to its den in its cheeks.[8]
