Delmarva Peninsula Fox Squirrel

Sciurus niger cinereus

Description

The fox squirrel species (Sciurus niger ) comprises nine subspecies in the United States, one being the Endangered Delmarva Peninsula fox squirrel, Sciurus niger cinereus. Fox squirrels are the largest of the North American squirrels, attaining a length of 28 in (71 cm) and a weight of 3 lbs (1.5 kg). The Delmarva subspecies is slightly smaller in length and weight. The pelt ranges from a uniform gray to a reddish fox color above with white underparts. Ears are small and round.

Behavior

The Delmarva fox squirrel spends much of its time on the ground, feeding on and caching the fruits of oak, hickory, beech, walnut, and loblolly pine. It does not hibernate but lives on stored foods in winter. In spring, it forages on the buds and flowers of trees, and on fungi, insects, fruit, and an occasional bird egg. Unlike the gray squirrel, which invariably climbs trees to escape predators, the Delmarva fox squirrel often leaps to the ground from a tree and outruns the threat.

Fox squirrels have one extended breeding season with two peaks, in March and August. After a gestation period of about 45 days, the female bears a litter of three blind and hairless young. These open their eyes at five weeks, and are weaned between nine and twelve weeks of age. The female cares for her young alone.

Habitat

Found in mature stands of hardwoods and pines, most often among loblolly pines, the Delmarva fox squirrel is restricted to larger groves along streams, bays, or salt marshes. This squirrel prefers the eco-tones, or transitional habitats, where forest grades into scrub or grasslands. The woodlot must be of a sufficient size and maturity to provide enough food for a breeding population, yet adjacent to more open park-like foraging grounds.

Distribution

The Delmarva fox squirrel once ranged through southeastern Pennsylvania, Delaware, south-central New Jersey, eastern Maryland, and the Virginia portion of the Delmarva Peninsula. It was hunted in Pennsylvania, where it was known as the stump-eared squirrel. Because of more specific habitat requirements, the Delmarva fox squirrel was never as numerous as the gray squirrel. Populations were dispersed and discontinuous. By the turn of the century, agricultural practices and increasing human populations drove the squirrel from New Jersey, Pennsylvania, and Virginia. A small population survived in Delaware until the 1930s.

Threats

The decline of this squirrel can be directly attributed to intensive agriculture and spreading urbanization. Agricultural practices significantly altered the stands of old-growth forests within the squirrel's range. Residential development cleared large tracts of woodland, and the fox squirrel was forced out.

Conservation and Recovery

Stable populations of the fox squirrel are serving as "donors" to reestablish new colonies throughout the former range. Populations have been translocated to Cecil, Kent, Somerset, and Worcester counties in Maryland. In 1982, a new population was established in Northampton County, Virginia. In 1984, an experimental population was relocated to Sussex County, Delaware, where it is apparently thriving. In May 1986, six squirrels from Maryland were released at Prime Hook National Wildlife Refuge in Delaware, the second of three planned releases to restore the animal to its former range in the state.

One of the most successful recovery actions taken for the squirrel comes in the form of nest boxes, as evidenced by surveys conducted in the spring of 1991. For more than a decade, boxes had been installed at selected sites designated by the Delmarva fox squirrel recovery team as benchmarks. At the Chincoteague Refuge, where nest boxes had been installed for some time, a record total of 51 fox squirrels were observed in the boxes in 1991, including three litters totaling five young-of-the-year. At Eastern Neck Refuge, where nest boxes had not yet been installed by the time of the 1991 survey, a total of 329 trap days yielded only four fox squirrels. However, two of these were immature, indicating that fox squirrels reproduced the previous year and the young had survived the winter. The survey also found that newly installed nest boxes at one state-owned site yielded two adult females and three young-of-the-year. Such dramatic results represent the likelihood of continued success for the use of nest boxes to help propagate the species.

Contact

U.S. Fish and Wildlife Service
Division of Endangered Species
300 Westgate Center Drive
Hadley, Massachusetts 01035
http://northeast.fws.gov/

Reference

U.S. Fish and Wildlife Service. 1983. "Delmarva Peninsula Fox Squirrel Recovery Plan." U.S. Fish and Wildlife Service, Newton Corner, Massachusetts.