The golden-mantled ground squirrel, known by its scientific name Callospermophilus lateralis is a ground squirrel often mistaken for a chipmunk that is present in the mountains in San Bernardino County and generally in mountainous areas and forest habitats as well as well as rocky meadows and sagebrush flats of western North America. Spermophilus lateralis is known to survive at altitudes as high as 14,115 feet at Pike’s Peak in Colorado, and thrives at the 4,000 foot level in the northern Sierra Nevada mountains of California, as well as within the mixed coniferous forests of the Klamath, Cascade and Sierra Nevada ranges, up to and above the timberline, in forest-edged meadows and the chaparral habitat in southern California. Spermophilus lateralis is abundant in campgrounds where the squirrels are treated to human handouts.
A typical adult ranges from nine to 12 inches in length and from four ounces to 14 ounces. Strikingly colored, spermophilus lateralis has a golden-red mantle that extends from the head down over its shoulders. One white stripe, bordered by two black stripes, extends horizontally down the body, similar to chipmunks. Although chipmunks have a white stripe through their eyes, Spermophilus lateralis has a whitish fur eye ring and no facial striping. The back is gray, brownish or buff, and their undersides are whitish or yellowish-gray. The tail is brownish-black above, and reddish brown on the underside. Winter pelage is grayer and the mantle is duller. The species is sexually dimorphic, with males having a brighter red mantle as well as a significantly larger brain size.
A hibernator, it builds up its body to make it through its winter asleep, and also stores some food in its burrow, like the chipmunk, for consumption upon waking in the spring. Both the golden-mantled ground squirrel and the chipmunk have cheek pouches for carrying food. Cheek pouches allow them to transport food back to their nests and still run at full speed on all fours.
It eats seeds, nuts, berries, insects, and underground fungi. It is preyed upon by hawks, jays, weasels, foxes, bobcats, and coyotes.
Male golden-mantled ground squirrels are polygynous. After emergence from hibernation, they compete with each other to establish territorial boundaries. Male territories encompass the territories of several females. When females emerge from hibernation roughly two to three weeks after the males, they typically mate with the male on whose territory they are found.
The gestation period is 26 to 33 days, with young being born from May to the beginning of September, depending on altitude. Most litters arrive from May to late June. Females have one to two litters per year. Litter size ranges from two to eight pups, averaging five. Litter size is larger at lower elevations.
Like many rodents, spermophilus lateralis pups are born hairless except for tiny whiskers and hairs on their head, toothless, their toes fused together and their ears closed. Their fur and stripes become visible after a week and their teeth erupt, ears open after two weeks. They begin to eat solid food at around a month old, at which time their growth rate is rapidly accelerated. Pups leave the natal burrow when they are roughly 25 percent of the adult body size, and are weaned sometime after they are 29 days old.
Care for the pups is provided by the female only, and that declines 2 to 3 weeks after the pups leave the nest, after which the female becomes antagonistic towards her offspring. Females and males reach sexual maturity within the first year.
The likely lifespan golden-mantled ground squirrels has been documented as an average of seven years in the wild, and five years in captivity. This does not take into account juvenile mortality, much of which must remain unknown to observers. The relative longevity of animals in the wild is atypical, as captive animals not facing dangers of predation and food shortage typically live longer than their wild counterparts.
This species of ground squirrel is classified as asocial, which is the least social out of five social group types. Cohesiveness between individuals has only been seen in brief intervals between males and females when breeding, for a longer duration between females and young until dispersal and between littermates until dispersal.
The home range of spermophilus lateralis varies from a half acre to two-and-a-half acres, depending on vegetation density. Females and males do not share territories, which include their burrow and up to 90 feet surrounding it, except during the mating season, when males overlap their territories with females.
Fighting occurs occasionally between adults.
Despite their occasional hostility toward one another, golden-mantled ground squirrels are known to make alarm calls to warn others of danger from predators. This behavior imparts a potential cost to the caller, as it allows a predator to focus on it. It may succumb to predation because it has given the call. This type of behavior is typically seen only in species where kin are likely to be alerted and saved because of the alarm call. This behavior, then, may be considered a kind of kin preference, even if other behavior of the squirrels does not seem to indicate preferential treatment of kin.
Golden-mantled ground squirrels are mostly diurnal, but can be active at any time during the summer. They hibernate in areas where the ground freezes, or is covered in snow. Hibernation begins between late August and November, depending on elevation, and ends between late March and May. The squirrels curl up in a ball to minimize surface area. Hibernation is broken up into bouts of torpor, interspersed with wakeful periods.