Sciurus carolinensis, common name eastern gray squirrel or grey squirrel depending on region, is a tree squirrel in the genus Sciurus. It is native to eastern North America, where it is the most prodigious and ecologically essential natural forest regenerator. The eastern grey squirrel in Europe is regarded as an invasive species.
Description[]
Although a familiar mammal in many parts of Great Britain, the grey squirrel (Sciurus carolinensis) is non-native, having been first introduced from the eastern USA in 1876. It is responsible for the decline in populations of the UK's native red squirrel (Sciurus vulgaris). The introduced species is larger than the red squirrel, has largely grey fur with touches of russet-brown, and white underparts. Unlike the red squirrel, this species never has ear tufts. The sexes are similar in appearance.
Biology[]
Grey squirrels are active during the day; they feed on seeds, nuts, buds, insects, bird eggs and fungi, depending on the time of year, and are well-known for their habit of hoarding food in autumn to see them through the harsh winter months. Seeds, cones or nuts are hidden in small scrapes scattered over the ground and buried. The general area is remembered, and then the cache is re-found by smell over fairly short distances.
Breeding takes place in December to February, and again in March to May. During this time, a number of males may follow a female when she is about to come into oestrus; during this 'following phase' the female may occasionally turn on the male and rebuff his advances by lunging at him aggressively. The day the female comes into oestrus, a number of males chase the female, making 'buzzing' noises; this is known as the 'mating chase', and the female can respond aggressively to males. Through much male-male chasing, dominant males are able to get closer to the female; when she is ready she crouches on the ground, and the first male to reach her mates with her. Gestation takes up to 44 days, during which time females are solitary, and nest in a 'drey' of twigs and leaves. If conditions are good, two litters are produced each year, consisting of one to eight young. The young are usually weaned by ten weeks, and reach sexual maturity at 10 to 12 months of age. The average lifespan is eight to nine years.
Diet[]
Eastern gray squirrels eat a range of foods, such as tree bark, tree buds, berries, many types of seeds and acorns, walnuts, and other nuts, and some types of fungi found in the forests, including fly agaric mushrooms (Amanita muscaria). They can cause damage to trees by tearing the bark and eating the soft cambial tissue underneath. In Europe, sycamore (Acer pseudoplatanus L.) and beech (Fagus sylvatica L.) suffer the greatest damage.
Eastern gray squirrels have a high enough tolerance for humans to inhabit residential neighborhoods and raid bird feeders for millet, corn, and sunflower seeds. Some people who feed and watch birds for entertainment also intentionally feed seeds and nuts to the squirrels for the same reason. The squirrels also raid gardens for tomatoes, corn, strawberries, and other garden crops. Sometimes they eat the tomato seeds and discard the rest. On very rare occasions, when their usual food sources are scarce, eastern gray squirrels also prey upon insects, frogs, small rodents including other squirrels, and small birds, their eggs, and young. They also gnaw on bones, antlers, and turtle shells – likely as a source of minerals scarce in their normal diet.
Predation[]
Predators include humans, hawks, weasels, raccoons, foxes, domestic and feral cats, snakes, owls, and dogs. In its introduced range in South Africa, it has been preyed on by the African Harrier-Hawk.
Range and Habitat[]
Introductions of this species to the UK continued up until 1915. Between 1930 and 1945 it underwent a huge expansion in range; it is now common throughout central and southern England, Wales and the central lowlands of Scotland, and is still increasing in terms of range and numbers. The grey squirrel has also been introduced to South Africa, Australia and Italy. In Italy the grey squirrel has extended its range into the Alps and Piedmont, and it seems likely that it will now spread throughout much of Europe. Its native range extends throughout the eastern USA reaching as far north as Canada, and south to the Mississippi River. A very adaptable species, the grey squirrel prefers mature broadleaved woodlands with a rich understorey layer. It also occurs in conifer woodlands, urban areas where there are mature trees, as well as gardens and parks.
Gallery[]
.png "Squirrel (Wild Kratts).png (256 KB)")
.png "Squirrels, Eastern Grey (Total Drama Island).png (344 KB)")
