Everything about The Western Gray Squirrel totally explained
The
Western Gray Squirrel (
Sciurus griseus) is an
arboreal rodent found along the western coast of the
United States and
Canada.
At various times and places, this species has also been known as the Silver-gray Squirrel, the California Gray Squirrel, the Oregon Gray Squirrel, the Columbian Gray Squirrel, the Banner-tail, and also simply as the Gray Squirrel. There are three geographical subspecies:
Sciurus griseus griseus (central
Washington to the western
Sierra Nevada in central
California);
S. g. nigripes (from south of San Francisco Bay to
San Luis Obispo County, California; and
S. g. anthonyi, which ranges from
San Luis Obispo to south-central California).
The Western Gray Squirrel was first described by
George Ord in 1818 based on notes taken by
Lewis and Clark at
The Dalles in
Wasco County,
Oregon.
Compared with the
Eastern Gray Squirrel S. carolinensis or the
Eastern Fox Squirrel (which have been introduced into its range), these squirrels are shy, and will generally run up a tree and give a hoarse barking call when disturbed.
Weights vary from about 400 g to nearly 1 kg, and length (including tail) from 45 to 60 cm. It is the largest native tree squirrel in the western coastal United States. Western Gray Squirrels exhibit a form of coloration known as counter shading. The dorsal fur is a silver gunmetal gray, with pure white on the underside; there may be black flecks in the tail. Ears are large but without tufts. The ears turn reddish-brown at the back in the winter. The tail is long and typically very bushy. Tree squirrels undergo a complete head-to-tail molt in the spring and a rump-to-head molt in the fall. Tail hair is replaced only in the spring. Also, nesting mothers will use their tail hair to line birthing nests.
Western Gray Squirrels mate over an extended period ranging from December through June. Young are born after approximate 44 day gestation period. Juveniles emerge from nests between March and mid-August. Litter sizes range from one to five
kits which remain in the nest for a longer period that other squirrels. The kits are relatively slow in development, and won't leave the nest for six months or more another species disadvantage when in competition with other, more-rapidly fledgling squirrels. Young gray squirrels have furled tails which won't reach fullness until adulthood. This is a good indicator of age and maturity. Mother squirrels often appear have a stressed and overworked, complete with bruised and battered nipples. Mating squirrels can be very sadistic and will bite and injure each other. Females can be quite territorial, and will chase others away and have fairly violent altercations between themselves.
Western Gray Squirrels are
forest dwellers, and can be found at elevations up to at 2,000 m or more. Time on the ground is spent foraging, but they prefer to travel distances from tree to tree. They are strictly
diurnal, and feed mainly on seeds and nuts, particularly pine seeds and
acorns, though that'll also take berries, fungus and other food.
Pine nuts and
acorns are considered critical foods because they're very high in oil and moderately high in
carbohydrates, which help increase the development of body fat. They feed mostly in trees and on the ground. They generally forage in the morning and late afternoon for acorns, pine nuts, new tree buds, and fruits. When on alert, that'll spread their tails lavishly, creating an umbrella effect that shields them and possibly provides cover from overhead predators. They are
scatter-hoarders making numerous caches of food when it's abundant, and thus contribute to the seed dispersion of their food trees. Although squirrels show relatively good scent relocation abilities, some food caches are never reclaimed, becoming seedlings in the spring. Though they don't hibernate, the do become less active during the winter. Like many prey animals, they depend on auditory alerts from other squirrels or birds to determine safety. Once an alarm call is transmitted, those present will join in, and the trees become a cacophony of barking squirrels. Tree squirrels are prey for bobcats, hawks, eagles, and mountain lions.
Squirrel nests are called
dreys and can be seen in trees, built from sticks and leaves wrapped with long strands of grass. There are two stick nest types made by the Western Gray Squirrel: the first is a large, round, covered shelter nest for winter use, birthing, and rearing young. The second is more properly termed a "sleeping platform," a base for seasonal or temporary use. Both types are built with sticks and twigs and are lined with leaves,
moss,
lichens and shredded bark. The birthing nest may be lined with tail hair. The nest may measure 43 to 91 cm (17 to 36 in) by up to 46 cm (18 in) and is usually found in the top third of the tree. Young or traveling squirrels will also "sleep rough" when weather permits, balanced spread-eagled on a tree limb high above the forest floor. This attitude is also adopted for cooling in hot weather, a behaviour also observed in raccoons.
The Western Gray Squirrel was listed as a threatened species in Washington state in 1993. Populations of the Western Gray Squirrel have not recovered from past reductions. They are threatened with habitat loss, road-kill mortality and disease. Habitat has been lost due to urbanization, catastrophic wild fires, and areas of forest degraded by fire suppression and overgrazing, allowing the invasion of Scot's Broom. Notoedric
mange, a disease caused by mites, becomes epidemic in Western Gray Squirrel populations and is a major source of mortality. Other species of Eastern Gray Squirrels, fox squirrels, California ground squirrels and
Wild Turkeys are expanding and compete with the Western Gray.
Listed as extirpated in some California areas, the Western Gray Squirrel in southern California is generally found only in the mountains and surrounding foothill communities. Local rehabilitation experts recount the Eastern Fox Squirrels were released in urban regions Los Angeles in the 1970s, and these aggressive cousins drove the more reclusive Western Grays back into the mountains, where competition wasn't so strong. This non-native species introduction appears to be the largest threat in the southern California area.
Further Information
Get more info on 'Western Gray Squirrel'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://western_gray_squirrel.totallyexplained.com">Western Gray Squirrel Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |