A lot of research has been done regarding S. beldingi, much of which focuses on the nepotistic and altruistic behavior involved in relation to predation. Emitting a warning call is altruistic because it puts the individual in danger in order to protect others. However, it has been observed that these warning calls are usually nepotistic, involving closely related individuals. Most squirrels do not give a warning cry for unrelated or distantly related individuals. It has also been found that S. beldingi has different calls for different situations. Calls are multiple-note trills when warning of terrestrial predators and single-note chirps when aerial predators are near. Males may even call after copulation, possibly to advertise their dominant status. (Leger et al 1984, Robinson 1984, Sherman 1981)
Perception Channels: tactile ; chemical
Spermophilus beldingi is not endangered but is in fact the focus of many population control measures. In many areas, poisonous baits are used in order to keep population numbers of S. beldingi down. Some natural predators of S. beldingi are coyotes, badgers, long-tailed weasels, raptors and snakes (Jenkins and Eshelman 1984).
IUCN Red List of Threatened Species: least concern
Spermophilus beldingi can be an agricultural nuisance, feeding on crops and other vegetation. (Jenkins and Eshelman 1984)
Spermophilus beldingi is primarily herbivorous but also eats insects, small invertebrates, birds' eggs, and some carrion. Its primary food sources are seeds, flowerheads, nuts, grains, roots, bulbs, mushrooms, and green vegetation. Seeds are the appropriately preferred food of Spermophilus (which means "seed loving") beldingi (Macdonald 1985). (Jenkins and Eshelman 1984, Nowak 1991)
Spermophilus beldingi is found in the mountainous regions of the western United States. Its range extends from eastern Oregon to southeastern Idaho, northeastern California, northern Nevada, and northwestern Utah (Nowak 1991). (Jenkins and Eshelman 1984)
Biogeographic Regions: nearctic (Native )
Spermophilus beldingi is a meadow-dweller. It is found in alpine and subalpine meadows and pastures. The habitats of S. beldingi seem to be limited to open areas as opposed to forests or rocky slopes. (Jenkins and Eshelman 1984, Nowak 1991)
Terrestrial Biomes: mountains
Spermophilus beldingi is a relatively small ground squirrel with a head to tail length of 230-300mm. Its tail is 44-76mm long and is bushy yet flattened, with reddish coloring on the ventral side. The pelage of the rest of the body is gray with touches of cinnamon on the undersides, and reddish-brown on the back. The tail may also contain red, black and white bands of colors on the distal hairs. Spermophilus beldingi has short limbs and small ears. The skull of S. beldingi has a short rostrum and convex dorsal profile. Auditory bullae are small and postorbital processes are conspicuous. The dental formula is 1/1, 0/0, 2/1, 3/3=22. Molars are hypsodont and there is a continuous metaloph on the fourth premolar. (Jenkins and Eshelman 1984, Macdonald 1985, Nowak 1991)
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 290 g.
Average basal metabolic rate: 0.796 W.
Spermophilus beldingi reaches sexual maturity at approximately 2 years. Mating occurs shortly after emergence from hibernation in May or June. Females are usually receptive to mating for only one day, and on that day may mate with numerous (between 3 and 5) different males. Some males may however, never mate. Mating occurs above ground but females create "nests" in their burrows for their litter. Gestation lasts approximately 23-28 days. Females have only 1 litter per year, and most litters are multiply sired. Litter sizes range from 1-11 but typically average around 5. Females usually have 5 pairs of teats and lactation lasts 26-31 days. Young are born at 5.4-8 g and are very altricial. Juveniles spend about 25-28 days below ground before emerging. Females of S. beldingi are the sole caregivers, with fathers spending no time helping to care for the young. Oftentimes the males never see the young because they are hibernating before the young emerge from their burrows. (Jenkins and Eshelman 1984, Macdonald 1985)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 6.87 g.
Average gestation period: 26 days.
Average number of offspring: 5.7.
Average age at sexual or reproductive maturity (male)
Sex: male: 547 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 365 days.
