Arctic ground squirrel

The Arctic ground squirrel (Urocitellus parryii) (Inuktitut: ᓯᒃᓯᒃ, siksik) is a species of ground squirrel in the squirrel family Sciuridae. It lives in the cold Arctic and Subarctic areas of the Northern Hemisphere, mostly in North America and Asia. These squirrels are very special because they can survive extreme cold that would be dangerous for most animals.

In some places like Alaska, especially around the Aleutian Islands, people call them "parka" squirrels. This name comes from the fact that their pelts were used to make the warm ruff around the neck of parkas and other winter clothes. These squirrels are very good at living in icy places, and they have special ways to stay warm and active even when the temperature drops very low.

Arctic ground squirrels are interesting because of how they prepare for winter. They dig deep burrows and can stay in a very low-energy state called hibernation for many months. During this time, their body temperature can drop close to the freezing point of water, which is something very few animals can do. This amazing ability helps them survive in some of the coldest places on Earth.

Taxonomy

The Arctic ground squirrel has many different types, called subspecies. These subspecies live in various cold places across North America and Asia. Some examples include the Barrow ground squirrel found in Northern Alaska, the Kodiak Island ground squirrel, and the St. Lawrence Island ground squirrel. Each subspecies has its own name and lives in a specific area.

Description

The Arctic ground squirrel has a beige-tan coat with light spots on its back. It has a shorter face and smaller ears than tree squirrels, with a dark tail and white markings around its eyes.

During the short summer, these squirrels shed their old fur and grow new coats to prepare for winter. In summer, their fur has reddish and yellow colors on the cheeks and sides, which change to a silvery color in the fall. This lighter winter coat helps them blend in with the snow and avoid predators like snowy owls and foxes. Arctic ground squirrels are about 39 cm (15 in) long on average. Females usually weigh around 750 g (26 oz), while males can be nearly 100 g (3.5 oz) heavier.

Distribution and habitat

The Arctic ground squirrel lives in parts of western Northern Canada, from the Arctic Circle to the Yukon, northern British Columbia and the Northwest Territories. It is also found in Alaska, the Alaska Peninsula, the Aleutian Islands, and across to the Russian Far East (Siberia), including the Kamchatka Peninsula. Special types live on St. Lawrence Island in the Bering Sea and on Kodiak.

These squirrels are adapted to the North American Arctic tundra. They like to live on hillside or mountain slopes, near rivers or lakes, and on open tundra. They prefer sandy soil because it is easy to dig through and drains well. They dig shallow tunnels and burrows where the frozen ground, called permafrost, does not stop them. Some types that live farther south prefer open meadows and tundra areas.

Fossil record

The Arctic ground squirrel has many fossils from the time of the Pleistocene. During the Last Glacial Maximum, these squirrels were common in places like the Klondike region, where they are now rare or not found. Scientists have studied old nests and food stores of these squirrels to learn about past environments. Plants like Calamagrostis canadensis, Carex albonigra, and Koeleria found in these stores show that a large grassy land covered the area long ago.

Behaviour

The Arctic ground squirrel lives on the tundra and can be eaten by animals like the Arctic fox, red fox, wolverine, Canada lynx, brown bear, snowy owls, and eagles. These squirrels hibernate during the winter, which means they sleep for a long time to save energy. In the summer, they search for plants, seeds, and fruit to eat so they can get fat for the winter.

When Arctic ground squirrels talk to each other, they use both sounds and body touches. They make different calls depending on what danger they see — deeper sounds for animals on the ground and quicker chirps for danger from the sky.

Hibernation

Arctic ground squirrels hibernate from early August to late April. During this time, their body temperature can drop very low, even below freezing, and their heart rate slows down to just one beat per minute. Scientists study this because it might help us keep human organs safe for transplants in the future. Even though their brain connections weaken during hibernation, they grow back when the squirrel wakes up.

Diet

These squirrels eat grasses, sedges, mushrooms, and other plants. They sometimes eat insects and even small animals like mice or young squirrels. They may carry food back to their homes in their cheeks.

Reproduction

Mating happens between mid-April and mid-May. After about 25 days, the females have a litter of about five to ten tiny, hairless babies. The babies are weaned after six weeks and then grow quickly to get ready for winter.

Conservation

The Arctic ground squirrel is considered to be in a safe condition. Experts say that there are enough of them around, so they are not in danger. They are listed as "least concern" by groups that watch over wildlife.