Belding’s Ground Squirrel, (Urocitellus beldingi)
Belding’s ground squirrel (Urocitellus beldingi), is also known as sage rat, picket-pin, or pot gut. This ground squirrel resides on mountains in the western United States, ranging from parts of Washington and Oregon, to central California and southwestern Idaho and even into the extremities of northwestern Utah. In California, between Kings Canyon and Lake Tahoe, the Belding’s ground squirrel will live in meadows at altitudes of 6,500 to 11,800 feet. This squirrel is of least concern on the IUCN’s Red List of Threatened Species.
The Belding’s ground squirrel is 9.1 to twelve inches long and weighs 10.24 ounces, making it a medium sized squirrel. It has short limbs and ears, with a greyish pelt that fades to a darker cinnamon color and a reddish brown on its back. The bushy and flattened tail of the Belding’s ground squirrel is 1.7 to three inches long, which has hairs with red, white, and black coloring.
Preferring to live at higher altitudes, the Belding’s ground squirrel will choose habitats in alpine and subalpine meadows, sagebrush flats, and farming fields and grasslands. They are limited to open areas and tend to live around water and lush vegetation. They do not prefer to live in tall grasses, rocky slopes, dense forests, or in areas with short grass because they cannot hide from predators there. Belding’s ground squirrels come out of their burrows at sunrise, the first one to exit remaining by the entrance until there are enough squirrels outside of the burrow to watch for predators. If the temperature is high, the squirrels will be less active, choosing to bask in the sunlight on rocks or in the dirt. Young Belding’s ground squirrels will play while outside and return to the burrow later than the adults, who return in the afternoon. They do not spend all of their time outside, however, but will also perform maintenance on their burrows and groom each other.
The Belding’s ground squirrel, although mainly herbivorous, will occasionally eat carrion, insects, and even members of its own species. Their diet consists mostly of flowers and seeds, but they will also eat nuts, roots, grains, mushrooms, bulbs, and green vegetation. These squirrels do not store their food; instead, they use fat reserves in times of hibernation. They can spend up to forty percent of the summer eating food in preparation for a long hibernation. The time at which hibernation begins for the Belding’s ground squirrel depends on its elevation, gender, and age. At higher elevation, adult males will begin hibernating between late July and early September, and females may follow toward the end of September. Young males will go into hibernation when they are ten weeks old, followed by the females at thirteen weeks. They hibernate at these times in order to avoid the heat of late summer. When in hibernation, females tend to hibernate together, while the males prefer to hibernate individually. Emergence depends on many factors, including the altitude of the squirrel’s habitat. At higher elevations, males will emerge in late April, while at lower elevations male Belding’s ground squirrels will emerge earlier, in February. The time at which females emerge is spread over a few weeks.
The family dynamics of the Belding’s ground squirrel are nepotistic, or family oriented. Most interactions will occur between the female squirrels and their relatives. The squirrels will use scent recognition to determine whether another squirrel is related to them or not. This is very important for the squirrel’s society to run smoothly, because it allows them to react properly when defending their nests and territories. Male ground squirrels are mainly nomadic between seasons, while the females live in groups and will occasionally share food and shelter with each other as long as they are kin.
Belding’s ground squirrels will usually mate in late May or early June after hibernation. The squirrels will mate with whomever they can, as the females are only receptive for five hours or less a year. The males will fight aggressively to get to the females, with the older, stronger males typically emerging victorious. Females can mate with up to five males per year, increasing the chances of pregnancy and genetic diversity.
Female Belding’s ground squirrels will give birth once a year, usually in late June to early July at higher elevations, producing a litter of up to eight babies. The nesting habits of the mother squirrels are particular. They will dig nests specifically for birthing and fill them with grasses and grass roots. Females will protect their nests and pups by chasing off any unrelated squirrels, and this will continue until the pups are weaned. Males leave the communities after mating, and so the responsibility of raising the young rests solely on the females. At higher elevations, pups are weaned at twenty-seven weeks, and will emerge from the burrow in late July or early August. Males will wander away soon after weaning or after a successful breeding, while females rarely leave the group they were born in. Sometimes infanticide, or the killing of baby animals, will occur. Adult females or young males are the typical killers. Sometimes, after dragging it away from its nest and killing it, the attacking squirrel will eat the pup. These killers are not usually from the same area or group as the pup, and female relatives will not harm their kin’s pups, but help to protect them from danger.
When defending territory or sensing a threat Belding’s ground squirrels emit one of two alarm calls in order to alert the whole colony to the danger. One is known as the trill, or churr call, and consists of a set of more than five notes in rapid succession. This type of call is reserved mainly for terrestrial predators, but also for predators who do not pose a huge threat. Squirrels may respond by running back into their burrow, standing to get a better view, or running to a nearby rock to investigate the threat. All squirrels will emit this call while fleeing. The other type of alarm call is called the whistle. It as an individual, high pitch note. This call is used to alert the colony of immediate threats, usually aerial. Any Belding’s ground squirrel’s in the area of the whistle call will crouch or run to the nearest cover for protection. If running from a predator on the ground, only the female squirrels with family will alert others, and only after reaching protection. In both cases, the first squirrel who calls will attempt to remain away from cover and watch the predator. Bobcats, weasels, badgers, and eagles are all among the predators of the Belding’s ground squirrel.
Image Caption: Belding’s Ground Squirrel (Spermophilus beldingi) in the Sierra Nevada Mountains, California, USA. Taken in Tuolumne Meadows in Yosemite National Park. Credit: Justin Johnsen/Wikipedia(CC BY 3.0)