The
Douglas Squirrel (Tamiasciurus douglasii) is a pine squirrelPine squirrels are squirrels of the genus Tamiasciurus. Currently only two species are classified in this genus, the American Red Squirrel T. hudsonicus and the Douglas Squirrel T. douglasii...
found in the Pacific coastal states and provinces of North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
. It is sometimes known as the Chickaree or Pine Squirrel, but since Chickaree is also used for the American Red SquirrelThe American Red Squirrel is one of two species of tree squirrel currently classified in the genus Tamiasciurus and known as pine squirrels The American Red Squirrel (Tamiasciurus hudsonicus) is one of two species of tree squirrel currently classified in the genus Tamiasciurus and known as pine...
and Pine Squirrel for the genus Tamiasciurus, these alternative names are better avoided. Variant spellings of the common name are Douglas' Squirrel
and Douglas's Squirrel. The
Native AmericansNative Americans in the United States is the phrase that describes indigenous peoples from North America now encompassed by the continental United States, including parts of Alaska and the island state of Hawaii. They comprise a large number of distinct tribes, states, and ethnic groups, many of...
of
Kings RiverThe Kings River is a major river of California. It arises in the Sierra Nevada, consisting of three forks. The Middle and South Forks start in Kings Canyon National Park, while the North Fork starts in the John Muir Wilderness. The South Fork flows in Kings Canyon: a spectacular deep glacial valley...
called it the "Pillillooeet", in imitation of its characteristic
alarm callIn the field of animal communication, an alarm signal is an antipredator adaptation referring to various signals emitted by social animals in response to danger. Many primates and birds have elaborate alarm calls for warning conspecifics of approaching predators. For example, the characteristic...
.
Description
John MuirJohn Muir was a Scottish-born American naturalist, author, and early advocate of preservation of U.S. wilderness. His letters, essays, and books telling of his adventures in nature, especially in the Sierra Nevada mountain range of California, have been read by millions and are still popular today...
described the Douglas Squirrel as "by far the most interesting and influential of the California
sciuridæThe sciurids or squirrels are a large family of rodents. The word Sciuridae means "shade-tail," and refers to the bushy appendage possessed by many of its members. It includes tree squirrels, ground squirrels, chipmunks, the marmots , and the true flying squirrels...
". It is a small, lively, bushy-tailed tree squirrel, enchanting to watch. Adults are about 33 cm in length (including its tail, which is about 13 cm long), and weigh between 150 and 300 grams. Their appearance varies according to the season. In the summer, they are a grayish or almost greenish brown on their backs, and pale orange on the chest and belly, while legs and feet appear brown. In the winter, the coat is browner and the underside is grayer; also, the ears appear even tuftier than they do in summer. Like many squirrels, Douglas Squirrels have a white eye ring.
Habitat
Douglas Squirrels live in coniferous forests, from the Sierra Nevada mountains of
CaliforniaCalifornia is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
northwards to coastal
British ColumbiaBritish Columbia is the westernmost of Canada's provinces and is famed for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . In 1871, it became the sixth province of Canada.The capital of British Columbia is Victoria, the 15th largest metropolitan region in Canada...
. They prefer old-growth or mature second-growth forest, and some authors regard them as dependent on its presence. They are active by day, throughout the year, often chattering noisily at intruders. In summer nights, they sleep in ball-shaped nests that they make in the trees, but in the winter they use holes in trees as nests. They are territorial; in winter, each squirrel occupies a territory of about 10 000 square metres, but during the breeding season a mated pair will defend a single territory together. Groups of squirrels seen together during the summer are likely to be juveniles from a single litter.
Diet
Douglas Squirrels mostly eat seeds of coniferous trees such as Douglas Fir,
Sitka SpruceThe Sitka Spruce is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 100 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter. It is by far the largest species of spruce, and the third tallest conifer species in the world...
and Shore Pine, though they do also eat acorns, berries, mushrooms, the eggs of birds such as
Yellow WarblerThe Yellow Warbler is a New World warbler. It is the most widespread Dendroica species, breeding in almost the whole of North America and down to northern South America. The yellow warbler is also sometimes called a Yellowbird.-Systematics and description:The Yellow Warbler has 35 subspecies,...
s, and some fruit. Unlike many other types of tree squirrel, they lack cheek pouches in which to hold food. They are
scatter hoardersHoarding or caching is type of animal behaviour where an animal will store its food within a cache, in times of surplus, for times when food is less plentiful...
, burying pine cones (which they cut from the trees while green) during the autumn. They often use a single place, called a
middenA midden, also known as a kitchen midden, or a shell heap, is a dump for domestic waste. The word is of Scandinavian via Middle English derivation, but is used by archaeologists worldwide to describe any kind of feature containing waste products relating to day-to-day human life...
, for peeling the scales off cones to get at the seeds. The discarded scales may accumulate for years, into piles more than a meter across as the same site is used by generations of squirrels. Their predators include
American MartenThe American marten is a North American member of the Mustelidae family, sometimes referred to as the Pine Marten. The term Pine Marten is also used to refer to a separate Martes species from Europe...
s,
BobcatThe Bobcat is a North American mammal of the cat family, Felidae. With twelve recognized subspecies, it ranges from southern Canada to northern Mexico, including most of the continental United States. The Bobcat is an adaptable predator that inhabits wooded areas, as well as semi-desert, urban...
s, domestic cats, Northern Goshawks, and
owlThe Owls are the order Strigiformes, comprising 200 birds of prey, species. Most are solitary, and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, though a few species specialize in hunting fish. They are found in all regions of the Earth except...
s; although they quickly acclimatise to human presence, humans can be a threat to them, through robbing of their cone caches to find seeds for tree cultivation and through the destruction of old growth forest. However, the squirrels' numbers appear to be unaffected by commercial thinning of forests.
Mating can occur as early as February. Gestation is about four weeks, and the young (which are
altricialAltricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
) are weaned at about eight weeks of age. There may be up to six kits in a litter, though four is more usual. In the southern and lower parts of their range they produce two litters each year.
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