North American red squirrel

Tamiasciurus hudsonicus

TAXONOMY

Tamiasciurus hudsonicus (Erxleben 1777), Hudson Bay, Canada. OTHER COMMON NAMES

English: Pine squirrel, chickaree; French: Ecureuil de l'Hud-son; Spanish: Ardilla de Douglas.

PHYSICAL CHARACTERISTICS

Head and body length 7-9 in, (178-230), tail 3.5-6.3 in (90-160 mm); 6.4-8.8 oz (180-250 g). Fur reddish brown or olive gray, underside white or faint yellowish. Tail with yellowish to rusty tips with a black band. White eye ring.

DISTRIBUTION

Boreal forests of Canada and the northern United States from Alaska in the west to Quebec and Main in the east. Fragmented populations in the Apalachian mountains and as far southeast as North Carolina, introduced to Newfoundland. Southward in the west, the species occurs in the Cascade and Rocky mountains and on Vancouver island. There are also isolated populations in subalpine "sky-island" habitats in New Mexico and Arizona.

HABITAT

Coniferous forests as well as coniferous-deciduous stands. Other habitats include aspen, red pine and Norway spruce. Red squirrels are territorial and a single individual of either sex occupies and defends a territory.

BEHAVIOR

Diurnal activity pattern. They use vocal calls during courtship and to defend their territory. Four vocalizations and an alarm

call were connected with territorial behavior in a study of the species in the Cascade Mountains, British Colombia.

FEEDING ECOLOGY AND DIET

Main diet are conifer and deciduous tree seeds and fungi. Other items include tree buds, flowers and sap, bark and insects. The species larder hoards cones in a central cache site (midden) that typically mark the center of the territory. Scat-terhoarding of cones has also been observed. Whitebark pine cones are an important food of grizzly bears in Yellowstone and they are know to excavate red squirrel middens.

REPRODUCTIVE BIOLOGY

Polygamous. Timing of breeding varies throughout the range. Courtship is thought to begin when bare patches of ground appear at the end of winter. During the breeding period males leave their territories more often and females allow males to enter their territories. Females come into estrus for only one day. Litter sizes vary between 3-6 young.

CONSERVATION STATUS

Isolated populations such as the Mt. Graham red squirrel subspecies in Arizona are protected and considered endangered.

SIGNIFICANCE TO HUMANS

Hunted or trapped for fur in some areas. ♦

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