Eastern Gray Squirrel

## Description

The eastern gray squirrel (Sciurus carolinensis ), also known, particularly outside of North America, as simply the grey squirrel, 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. Widely introduced to certain places around the world, the eastern gray squirrel in Europe, in particular, is regarded as an invasive species.

In Europe, *Sciurus carolinensis* is included since 2016 in the list of Invasive Alien Species of Union concern (the Union list). This implies that this species cannot be imported, bred, transported, commercialized, or intentionally released into the environment in the whole of the European Union.

## Appearance

The Eastern gray squirrel is a tree squirrel of medium size, and both males and females are of the same size and color. Its fur is mainly black or gray, the gray color being grizzled and often banded with gray and black guard hairs, tinged white, with the underside being white. Its tail is quite bushy and sometimes is reddish in color, and is used for maintaining balance while it leaps between branches. The overall fur color may change with different seasons, with the grayish fur being tawnier during summer, and the tail whiter.

## Distribution

Eastern gray squirrels are native to the eastern and mid-western parts of America, and to the south of the eastern parts of Canada. They range from Manitoba to New Brunswick, and south to Florida and East Texas. They inhabit large areas of mature, dense woodland ecosystems. These forests usually contain large mast-producing trees such as oaks and hickories, providing ample food sources. 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.

## Behavior

Eastern gray squirrels are aggressive, alert, and inquisitive rodents, very fast when moving and jumping amongst the treetops. These squirrels are a scatter-hoarder; they hoard huge quantities of food for the future and can make several thousand caches per season. They are more active in the daytime than at night, particularly at dawn and during the afternoon. Males and females may share the same nest during the breeding season, which they build in the forks of trees, and during cold winters, squirrels may also share these dreys to stay warm. The dens are usually lined with moss plants, thistledown, dried grass, and feathers. Females nest alone during pregnancy, and lactating females are particularly aggressive and left alone by other squirrels. These squirrels do not hibernate. To communicate with each other they use both vocalizations and posturing. They have a quite varied repertoire of vocalizations, including a squeak similar to that of a mouse, a low-pitched noise, a chatter, and a raspy "mehr mehr mehr". Other methods of communication include tail-flicking and other gestures, including facial expressions. Squirrels also make an affectionate coo-purring sound that biologists call the "muk-muk" sound. This is used as a contact sound between a mother and her kits and in adulthood, by the male when he courts the female during mating season.

## Diet

Eastern gray squirrels eat mostly the nuts, buds, and flowers of at least 24 types of oak trees, 10 species of hickory, beech, and walnut tree species, pecans, and truffles. Corn, wheat, and other crops are eaten, particularly in the winter. In the summer insects are eaten and are probably particularly important for young squirrels.

## Reproduction

Eastern gray squirrels have a polygynndrous (promiscuous) mating system. Males compete among themselves for the ability to mate with female eastern grey squirrels. Females may mate with more than one male as well. Breeding occurs in December-February and May-June and is slightly delayed in more northern latitudes. After a gestation period of 40-44 days, the female bears her litter of 1 to 9 (average 2 or 3) in a den or leafy nest. They are cared for in the nest by their mother until they reach independence. The young are weaned around 10 weeks, though some may wean up to 6 weeks later in the wild. They begin to leave the nest after 12 weeks, with autumn-born young often wintering with their mother. Most females begin their reproductive life at 1.25 years but can bear young as early as 5.5 months. Males usually are able to breed at 11 months.

## Population

### Threats

Eastern gray squirrels are not under any major threat.

### Number

The IUCN Red List and other sources don’t provide the number of the Eastern gray squirrel total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.

### Ecological niche

Eastern gray squirrels have an important role in the forest ecosystems where they live. They eat many seeds, and their seed-caching activities are likely to help in dispersing tree seeds. When they eat truffles, they may help distribute truffle fungal spores. They have an effect on the other animals in their ecosystem which they prey upon and are themselves preyed upon. They can cause damage in their native range and are sometimes considered a pest, in that they sometimes build nests in buildings, damaging electrical wiring and woodwork. The squirrels carry the disease parapox virus, which affects native squirrels.

## References

https://animalia.bio/eastern-gray-squirrel