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, but has since been introduced to European regions.
Like many members of the family Sciuridae, the eastern gray squirrel is a scatter-hoarder; it hoards food in numerous small caches for later recovery. Some caches are quite temporary, especially those made near the site of a sudden abundance of food which can be retrieved within hours or days for reburial in a more secure site. Others are more permanent and are not retrieved until months later. Each squirrel is estimated to make several thousand caches each season. The squirrels have very accurate spatial memory for the locations of these caches, and use distant and nearby landmarks to retrieve them. Smell is used partly to uncover food caches, and also to find food in other squirrels’ caches. Scent can be unreliable when the ground is too dry or covered in snow.
Squirrels sometimes use deceptive behavior to prevent other animals from retrieving cached food. They will pretend to bury the object if they feel that they are being watched. They do this by preparing the spot as usual, for instance digging a hole or widening a crack, miming the placement of the food, while actually concealing it in their mouths, and then covering up the “cache” as if they had deposited the object. They also hide behind vegetation while burying food or hide it high up in trees (if their rival is not arboreal). Such a complex repertoire suggests that the behaviors are not innate, and imply theory of mind thinking.
The eastern gray squirrel is one of very few mammalian species that can descend a tree head-first. It does this by turning its feet so the claws of its hind paws are backward-pointing and can grip the tree bark.
Eastern gray squirrels build a type of nest, known as a drey, in the forks of trees, consisting mainly of dry leaves and twigs. Males and females may share the same nest for short times during the breeding season, and during cold winter spells, squirrels may share a drey to stay warm. They may also nest in the attic or exterior walls of a house, where they may be regarded as pests, and as fire hazards due to their habit of gnawing on electrical cables. In addition, squirrels may inhabit a permanent tree den hollowed out in the trunk or a large branch of a tre
Eastern gray squirrels are crepuscular, or more active during the early and late hours of the day, and tend to avoid the heat in the middle of a summer day. They do not hibernate.
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. They can cause damage by tearing the tree bark and eating the soft cambial tissue underneath. In Europe, sycamore and beech 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.
In the wild, eastern gray squirrels can be found inhabiting large areas of mature, dense woodland ecosystems, generally covering 100 acres (40 hectares) of land. These forests usually contain large amounts of dense understory vegetation that provides them sufficient amount of food sources and favorable shelters. Oak-hickory hardwood forests are preferred over coniferous forests.
Eastern gray squirrels generally prefer constructing their dens upon large tree branches and within the hollow trunks of trees. They also have been known to take shelter within abandoned bird nests. The dens are usually lined with moss plants, thistledown, dried grass, and feathers. These perhaps provide and assist in the insulation of the den, used to reduce heat loss. A cover to the den is usually built afterwards.
Close to human settlements, eastern gray squirrels are found in parks and back yards of houses within urban environments and in the farmlands of rural environments.
Updated on 19 July 2016, at 05:48.
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