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. They sun themselves for hours on elevated points, sometimes lying quiescent and again sitting bolt upright, but always watchful and ready to disappear at the slightest alarm. This watchfulness is necessary, for their enemies are abroad at all hours. They are the prey of bobcats, foxes, coyotes, weasels, snakes, and hawks. The golden chipmunk and its related subspecies are omnivorous feeders. They show a strong predilection for bacon when looting camp stores and eat any kind of meat with avidity. Young birds and birds’ eggs are devoured whenever found, as are also grasshoppers, beetles, flies, larvæ, and many other insects. The number of kinds of seeds eaten is almost endless and includes chinquapin and pine nuts, rhus, alfileria, violet, lupine, ceanothus, and others. They also eat roses and other flowers, green leaves, wild currants, gooseberries and other fruit, and small tuberous roots. They often climb bushes and low trees, at least 30 feet from the ground, after nuts and berries. The capacity of their cheek pouches is shown by one instance, when one animal was loaded with 750 serviceberry seeds. The pouches of another contained 360 grains of barley, another 357 of oats. Bold and persistent camp robbers, their depredations cover all articles of food, including bread and cake, and they sometimes do considerable injury to small mountain grain fields.