Eastern Grey Squirrel, Sciurus carolinensis
Common Names: grey squirrel
Species: Sciurus carolinensis
General Description: The Eastern grey squirrel is an arboreal member of the family Sciuridae. It can have two colour phases, appearing with a black coat in colder seasons and a grey coat in warmer temperatures. Males and females are the same size, with weights ranging from 300 to 710 g. The total body length of these squirrels is 380-525 mm, with their tail accounting for 150-250 mm of this length. The presence of the Eastern grey squirrel is indicated by nut and seed shells around the bases of trees, as well as diggings the squirrel makes in the forest floor, searching for cached food. These signs, however, may also indicate the presence of other squirrels in the area, such as the American red squirrel (Tamiasciurus hudsonicus) and the northern flying squirrel (Glaucomys sabrinus).
Geographical Distribution and Habitat Requirements: The range of the Eastern grey squirrel extends from Florida to Southern Ontario and Quebec. They can be found west as far as Missouri and Texas, and east into New Brunswick. These arboreal mammals mainly occur in mature forests as they require the thick canopy for nests and protection. However, the Eastern grey squirrelcan also be found in urban areas. The survival ability of these squirrels in urban habitats has not yet been determined.
General Biology: The diet of the Eastern grey squirrel consists mostly of berries, seeds and nuts, as well as fungus when available. An opportunistic feeder, it will also eat bird eggs, bones, and frogs. These squirrels have two breeding seasons – December to February, and May to July – during which they produce litters of up to three individuals. Males and females become sexually mature after one year, and remain reproductively active for the rest of their lives. The grey squirrel is diurnal and remains active year-round. Home ranges average to be 5 ha, and males usually have larger home ranges than females. These squirrels are not territorial andcan have overlapping home ranges. In the winter, it is common to have several squirrels sharing a nest. Grey squirrels use three types of nests: winter dreys, summer dreys, and dens. Winter dreys consist of interwoven twigs as an outer shell, with leaves, feathers and moss lining theinside. These waterproof enclosures can be up to 45 cm in diameter, and are usually built in the canopy to avoid predators. Summer dreys are less elaborate than the winter nests. As well, the Eastern grey squirrel is able to use holes in hollowed-out trees year-round for dens.
Conservation: The Eastern grey squirrel is a common mammal and is not endangered. Their population is rapidly expanding and is occupying new territories. In recent years, it has moved into Southern New Brunswick from Quebec and the U. S. The primary threat to the Eastern grey squirrel is forestry practices such as clear-cutting, as thick canopies and old growth forest stands are used for protection and nesting. Predators of the Eastern grey squirrel include owls and hawks, as well as weasels, foxes, and wolves. Snakes and raccoons also prey often on the squirrels’ young. Squirrels, including the Eastern grey, act as dispersal agents for seeds, aiding in reforestation. Often, caches are not located by the squirrels and the stored seeds germinate to produce trees and other forest plants. Also, as a mycophagous mammal, the Eastern grey squirrel may play as important role in the dispersal of hypogeous mycorrhizal spores. This squirrel species is quickly moving east into New Brunswick, and eventually into Nova Scotia. It is not yet known what effect this larger squirrel will have on resident species of squirrels in these regions, such as the red squirrel and the Northern flying squirrel, nor on the populations of other small mammals.