GRAY SQUIRREL (and black phase)
Sciurus carolinensis
RUSTY FOX SQUIRREL
Sciurus niger rufiventer FOX SQUIRREL
Sciurus niger
Their vertical distribution extends from a moderate elevation above the sea in Oregon to above 11,000 feet in southern California. They are common in the Yellowstone and other national parks, where their size, bright markings, and activities render them conspicuous.
Everywhere their habits resemble those of the various species of true chipmunks with which they associate. They live in burrows, which they dig under the shelter of logs, rocks, stumps, roots of trees, or even in open ground, as well as in the ready-made shelter of rock slides, with conies, at timberline. Their burrows at times have several entrances within a small area. Often they occupy the burrows of other animals, including pocket gophers. They excavate burrows under cabins or barns in clearings, and abandoned mining camps or old sawmill sites frequently abound with them. Nests and storage chambers are excavated off the passageways. The nests are usually made of leaves and other soft vegetable material, but in the sheep country wool, which they find in scattered tufts, is often used.
A camping party in their haunts is certain to attract them, and, as about barns, it is necessary to keep a watchful eye on them to prevent their robbing grain sacks or other supplies. When they once locate an accessible supply of grain their industry is remarkable. I have seen a dozen or more working throughout the day, making continuous hurried trips, with loaded cheek pouches, to their dens, sometimes two hundred yards away. On approach of autumn they become continually active, gathering their winter supplies.
The length of their hibernation varies with the severity of the climate, but is rarely under five months. It is said to run through seven months on the higher mountains of southern California. They usually go into winter quarters in September or early in October, but occasionally one may be seen out as late as December. At this time they have become so fat that their movements are very sluggish. One kept as a pet for eleven years at Klamath Falls, Oregon, is reported to have hibernated regularly each winter. In Montana they retire to their dens in September and come out in March. They mate soon after they appear in spring and the young, four to seven in number, are half grown the last of May.
Like true chipmunks, these spermophiles are fond of weedy clearings or other openings in the forest, where stumps, logs, rocks, and old fences offer plentiful shelter and many elevated vantage points where they may sit by the hour watching the doings of their small world. They have a sharp whistling or chirping call note, usually uttered as a warning cry, but sometimes as a social call. They do not like gloomy or stormy weather and generally lie hidden at such times, but on sunny days are so actively engaged in foraging, running along the tops of logs, or perching on the tops of stumps and large rocks that they add greatly to the pleasant animation of the forests where they live. When running they usually carry the tail elevated like a chipmunk.