Sciurus carolinensis is a tree-dwelling squirrel commonly found in Vancouver since it was introduced into Stanley Park in 1914 (CWF 2017). The eastern grey squirrel is a rodent (Order Rodentia, Family Sciuridae), is closely related to chipmunks and marmots, and is one of nine species of squirrels in British Columbia (Nagorsen 2014).
Description:
S. carolinensis is one of the larger squirrels in British Columbia, with a body up to 25 cm in length and a conspicuous bushy tail of almost equal length. Its coat is generally grey in colour but is more frequently black in the northern part of its range (Burk & Grossenheider 1976; CABI 2005; Lawniczak 2002), causing it to be often mistaken for two distinct species (CWF 2017). Like other rodents, eastern grey squirrels have two pairs of incisors (large front teeth) that grow continuously. The length of the incisors, however, remains fairly constant as they are worn down by gnawing hard foods and other objects (Smith 1994).
Ecology:
S. carolinensis is native to eastern North America east of Mississippi River and north to southern Quebec and Ontario (CABI 2005; Lawniczak 2002). In addition to being introduced to British Columbia, it has also been introduced to several locations in Europe (CABI 2005), causing a decline in the populations of native squirrel species.
The eastern grey squirrel is commonly found in conifer/deciduous mixed forests, cultivated agricultural land, disturbed areas and suburban and urban areas (CABI 2005). It is active during the day, spending most of its time in trees and rarely venturing far from trees to gather food (Burk & Grossenheider 1976). It eats nuts, buds, flowers, fruits, fungi, some insects and occasionally bird eggs, but prefers the nuts produced by mature broadleaf oak, beech, walnut and chestnut trees (CABI 2005). In the fall, eastern grey squirrels cache excess food as a reserve for the winter months (CWF 2017).
Eastern grey squirrels are very nimble and quick in their movements, which helps them to evade natural predators that include the American mink, grey wolf, red fox, bobcat, lynx, and red-tailed hawk (Lawniczak 2002).
The eastern grey squirrel is commonly found in conifer/deciduous mixed forests, cultivated agricultural land, disturbed areas and suburban and urban areas (CABI 2005). It is active during the day, spending most of its time in trees and rarely venturing far from trees to gather food (Burk & Grossenheider 1976). It eats nuts, buds, flowers, fruits, fungi, some insects and occasionally bird eggs, but prefers the nuts produced by mature broadleaf oak, beech, walnut and chestnut trees (CABI 2005). In the fall, eastern grey squirrels cache excess food as a reserve for the winter months (CWF 2017).
Eastern grey squirrels are very nimble and quick in their movements, which helps them to evade natural predators that include the American mink, grey wolf, red fox, bobcat, lynx, and red-tailed hawk (Lawniczak 2002).
Life History:
S. carolinensis reach maturity at approximately 1 year old (11 months for males, 15 months for females). They breed twice a year — in December to February and May to June. A female can have 2–4 young per brood, producing a maximum of 8 young per year (Lawniczak 2002). The maximum life span in the wild is 12.5 years (Lawniczak 2002).
References cited:
Burk WH, Grossenheider RP. 1976. A field guide to the mammals of America north of Mexico. 3rd ed. Boston (MA): Houghton Mifflin Company.
[CABI] Centre for Agriculture and Bioscience International. 2005. Sciurus carolinensis (original text by IUCN/SSC Invasive Species Specialist Group). In: Invasive species compendium. Wallingford (UK): CAB International. [accessed 2018 Feb 1]. www.cabi.org/isc/datasheet/49075.
[CWF] Canadian Wildlife Federation. 2017. Hinterland who’s who, eastern grey squirrel. [accessed 2018 Feb 1]. http://www.hww.ca/en/wildlife/mammals/eastern-grey-squirrel.html.
Lawniczak M. 2002. Sciurus carolinensis. Animal Diversity Web (online). [accessed 2017 Jan 24]. http://animaldiversity.org/accounts/Sciurus_carolinensis/.
Nagorsen D. 2014. Mammals of British Columbia. [accessed 2018 Feb 1]. http://ibis.geog.ubc.ca/biodiversity/efauna/documents/MammalsofBCChecklist.pdf.
Smith D. 1994. Introduction to the Rodentia. [accessed 2018 Feb 1]. http://www.ucmp.berkeley.edu/mammal/rodentia/rodentia.html.
[CABI] Centre for Agriculture and Bioscience International. 2005. Sciurus carolinensis (original text by IUCN/SSC Invasive Species Specialist Group). In: Invasive species compendium. Wallingford (UK): CAB International. [accessed 2018 Feb 1]. www.cabi.org/isc/datasheet/49075.
[CWF] Canadian Wildlife Federation. 2017. Hinterland who’s who, eastern grey squirrel. [accessed 2018 Feb 1]. http://www.hww.ca/en/wildlife/mammals/eastern-grey-squirrel.html.
Lawniczak M. 2002. Sciurus carolinensis. Animal Diversity Web (online). [accessed 2017 Jan 24]. http://animaldiversity.org/accounts/Sciurus_carolinensis/.
Nagorsen D. 2014. Mammals of British Columbia. [accessed 2018 Feb 1]. http://ibis.geog.ubc.ca/biodiversity/efauna/documents/MammalsofBCChecklist.pdf.
Smith D. 1994. Introduction to the Rodentia. [accessed 2018 Feb 1]. http://www.ucmp.berkeley.edu/mammal/rodentia/rodentia.html.