Montana Field Guide

Eastern Fox Squirrel - Sciurus niger

A large squirrel that is highly variable in color, both individually and geographically. Over most of the range, the pelage is rusty yellowish with a pale yellow to orange (or light gray to dirty white) belly and a bushy tail bordered with fulvous-tipped hairs. In the Southeast, body may be sprinkled with yellow, white, and black, with the head mostly blackish except for the whitish nose and ears. In the vicinity of the Delmarva Peninsula, color may be pure steel-gray with no fulvous (Burt and Grossenheider 1964). Melanism is not uncommon. For adults, total length is 454-698 mm, tail length is 200-330 mm, and hind foot length is 51-82 mm (Hall 1981). Mass is 696-1361 g, with an average of about 800 g. There is a total of 20 teeth. The bones fluoresce bright red under longwave ultraviolet light (unique among normal adult mammals) (Flyger and Gates 1982). The fox squirrel of the southeastern Coastal Plain of North America is the largest tree squirrel in the western hemisphere. Weigl et al. (1989) reported an average mass of 1006 g in North Carolina and 962 g for 44 specimens collected in the Carolinas and northern Georgia. Western fox squirrels tend to be smaller (600 to 900+ g).

Larger than sciurus carolinensis, in which adults are 383-525 mm in total length and 340-700 g; also, niger has four cheek teeth on each side of the upper jaw (carolinensis usually has five), and in niger the tail hairs generally are not tipped with white (flyger and gates 1982).

Montana Range

Non-migratory.

Riparian Cottonwood forests. Riparian stands of Box Elder, Green Ash, Plains Cottonwood, and Willow and town parks. More prone to open forests than S. carolinensis.

More adaptable than S. carolinensis--nuts, seeds, corn, buds, flowers, tubers, bulbs, roots, arthropods, and birds' eggs. Scatter hoards fall mast crops in shallow holes.

Home ranges may be about 18.5 acres for adult males, 8.75 acres for adult females, 7.5 acres for juveniles, and 37.5 acres for juvenile males. Homerange size and pop. density determined by hab't quality and food crops.

In Montana probably 2 peeks: Dec-Jan and Apr-Jun. Var- iable. Youn may be born from Feb-Sep. Reach sexual matur- ity in 10 months.