Bryant's fox squirrel, Cat squirrel, Delmarva fox squirrel, Fox squirrel, Stump-eared squirrel
The Eastern fox squirrel (Sciurus niger) is the largest species of tree squirrel native to North America. Despite the differences in size and coloration, it is sometimes mistaken for American red squirrels or Eastern gray squirrels in areas where the species co-exist.
Eastern fox squirrels exist in three distinct geographical morphs in coloration: in most areas, their upper body is brown-grey to brown-yellow with a typically brownish-orange underside, while in eastern regions, such as the Appalachians, there are more strikingly-patterned dark brown and black squirrels with white bands on the face and tail. In the South, there are isolated communities with uniform black coats. To help with climbing, squirrels have sharp claws, developed extensors of digits and flexors of forearms, and abdominal musculature. Fox squirrels have excellent vision and well-developed senses of hearing and smell.
The natural range of this species extends over certain portions of southern Canada, the eastern United States, and northern Mexico. Meanwhile, introduced populations of the Eastern fox squirrel occur in British Columbia and Ontario (Canada) as well as California and Washington in the western part of the US. These squirrels prefer to live in open woodland with an open understory and scattered cover of trees. Within this habitat, they especially favor living among oaks, hickories, walnuts, and pines. They also occur in hedgerows and timbered fencerows that are adjacent to prairies. This type of habitat is also found in urban areas, where Eastern fox squirrels can occasionally be observed.
Eastern fox squirrels are mainly terrestrial, although they can also live in trees. They are generally not very social animals. However, there have been known cases of several individuals living in the same nest during the winter months. Each individual has its own territory, which often overlaps with these of conspecifics. Females and their offspring are known to fiercely defend the central parts of their range. Eastern fox squirrels are diurnal foragers and are active throughout the year. They usually nest in a tree called dreys. Nests are used as daily shelters and sites for raising offspring. They construct their nest out of leaves and occasionally nest in tree cavities, especially during the winter. The major forms of communication are scents, vocalizations as well as tail and body postures. Vocalization includes a wide variety of barks. They typically use a chattering sound as an alarm call, whereas a tooth chattering serves as a display of aggression. They also use scent-marking to communicate with other fox squirrels.
Eastern fox squirrels are omnivores, they generally feed upon plant matter and gall insects, including moths, beetles, bird eggs, and dead fish. They complement this diet with seeds such as these if acorn, hickory, walnut, mulberry, and Hawthorne.
Eastern fox squirrels have a polygynandrous (promiscuous) mating system, where individuals of both sexes have multiple mates. However, males usually compete for their mating right. These rodents have two defined breeding seasons, one of which occurs in December-February, and the other lasts from May to June. The gestation period lasts for 44-45 days, yielding a litter of up to 7 young with an average of 2-3. Females are able to produce 2 litters per year but generally yield only a single litter. Newborn babies are naked and cared by their mothers for the first 7-8 weeks of their lives, during which period they live in the nest. Leaving the nest, the female covers her offspring with nesting material. Complete weaning occurs at 12-14 weeks old, but the young become fully independent only at 16 weeks old. The age of reproductive maturity is 10-11 months old for males and 8 months of age for females.
Currently, this species is threatened by the loss of its natural habitat which results in a sharp population decline. Thus, the population in certain parts of Florida suffers from excessive logging of their pine forest habitat as well as development such as urbanization. On the other hand, their habitat is now becoming less favorable due to the prevention of fires, which cause an overgrowth of understory vegetation. And finally, this rodent is commonly hunted across the United States as a popular game species.
According to IUCN, the Eastern fox squirrel is abundant and widely distributed but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) and its numbers remain stable.
On one hand, feeding on a wide variety of seeds, the Eastern fox squirrels have a huge impact on the ecosystem of their range, helping many plants survive. This is largely due to their habit of storing food items: burying seeds underground, they often forget them. As a result, many of these seeds consequently sprout. On the other hand, because of being common and widespread throughout their range, these animals are a key prey species for a number of small predators.