The following pages contain a wealth of information about Belding's ground squirrel, gleaned from several sources. If you would like more information, see the resource page for more sources. If you would like a quick summary before reading in depth, see the summary page.
Belding’s ground squirrel (Spermphilus beldingi) is an extraordinary animal whose adaptations to its extreme environment and potentially nepotistic behaviors have drawn the interest of many scientists. The way in which S. beldingi lives, including its basic social structure and social relationships, is profoundly affected by its need to hibernate, by the availability of its food source, by predators, and by infanticide. Its incredible ability to survive these pressures, and to thrive, makes S. beldingi a fascinating and worthy rodent to study.
.General Description:
S. beldingi are members of the family Sciuridae. They were discovered in 1888 by Lyman Belding, and were subsequently named after him (Sherman and Morton 1979). There are three different subspecies of Belding’s ground squirrels, Spermophilus b. beldingi (recognizable by their darker coats), Spermophilus b. oregonus, and Spermophilus b. creber (Turner 1972). Spermophilus beldingi are considered diurnal, group-living rodents, meaning that they are active during the day, and that they live in colonies (Holekamp 1986, Sherman and Morton 1979). Physically, they are medium-sized ground squirrels with short legs and tails. They are typically a dusky shade of gray (varying to cinnamon on their back and cream on their stomachs). The eyelids of S. beldingi are white, and its whiskers and claws are black (Grinnell and Dixon 1918).They are typically eight to ten inches long, and their tail is approximately 3 inches long (Sherman and Morton 1979). . The old individuals are generally the largest, and the male average size is a bit larger than that of the females, though both weigh an average 8 ounces (Grinnell and Dixon 1918)..
Habitat:
Belding’s ground squirrel is found in a large portion of Northwestern United States. The squirrel's general range extends from northeastern Oregon, parts of Washington, southwestern Idaho, north and central Nevada, central California, and into northwestern Utah (Jenkins and Eshelman 1984, Sherman and Morton 1979). Specifically, S. b. beldingi is found in moist meadows high in the Sierra Nevadas, with its range extending south to Fresno, California and west into Western Central Nevada. S.b. oregonus is also found in high moist meadows in the Cascade Mountains and the Sierra Nevadas. Its range extends from the eastern areas of Oregon (except southeast corner), northeast California, and northwest Nevada to the Cascade divide. Finally, S.b. creber lives in central and north Nevada, the southeast corner of Oregon, and a small part of northwestern Utah.
Belding’s ground squirrels are found
in a variety of habitats in the far western United States. They prefer
to live at higher altitudes, and are profoundly affected by
warmth (Grinnell and Dixon 1918, Turner 1972). They are
typically found in alpine
and sub alpine meadows (Holekamp 1986).
They are also often found in
meadows at somewhat lower elevations, alfalfa fields that are
not plowed or flood irrigated, and pastures. Most importantly, Belding’s
ground squirrels like to live around succulent vegetation and water.
They
will not live in dense forests, tall heavy grass, steep or rocky slopes,
or thick shrubbery because they are not able to watch for predators.
In addition, they
do not
tend to live in extremely short grass because they cannot freeze or
hide in the presence of predators (Turner 1972, Grinnell and Dixon
1918).
A day in the Life of Belding’s ground squirrel
A typical day for the Belding’s ground squirrels begins when the sun first strikes its burrow and it ventures out. The first squirrel above ground will stay near its burrow until there are enough other squirrels above ground to watch for predators. Then the squirrels will move away from their burrows to forage. The squirrels are most active in the morning. For example, digging and feeding occur most often in the morning (Turner 1972). As the temperature increases, squirrel activity decreases. The squirrels spend large amounts of time stretched out on rocks or on the ground absorbing the warmth from the sun, or grooming (Loehr and Risser 1977). Other daily, above-ground activities of Belding’s ground squirrel include foraging, making and maintaining burrows, sun bathing, grooming (groom with paws and by rolling in the dust), exploring (especially the males), and collecting nest material (Turner 1972). If a female has young, she will often leave them to move about her home range and forage. If the young are above ground, they will play mostly with each other, though they will “make new friends” as they get older (Holmes 1994). Belding’s ground squirrel will go back into its burrow in the afternoon when the shadows start to fall or when it is cloudy. In both cases, the juveniles will stay out of their burrows much later than the adults (Turner 1972). At night, unrelated juveniles will occasionally share the burrow with a dam and her young, but for the most part the dam and siblings will interact most until the young disperse (Holmes 1994).
