Ground squirrels are widespread rodents that inhabit diverse landscapes across the globe. Part of the squirrel family (Sciuridae), they are well-adapted to life on the ground. They are a common sight, recognized for their burrowing habits and alert postures.
Defining Characteristics
Ground squirrels are typically long-bodied rodents with short legs, robust claws, and small, rounded ears. Their body length can range from approximately 6 inches to over 30 inches, with weights varying from a few ounces to several pounds, depending on the species. The Arctic ground squirrel, for instance, is among the largest North American species, reaching lengths of up to 495 mm and weights of 1500 grams. Their fur coloration is diverse, from gray, tawny, and pale brown to olive, reddish, or dark brown. Many species display distinctive patterns such as dappling, lines of spots, or stripes, though their undersides are usually lighter.
These rodents possess a shorter, less bushy tail compared to their tree-dwelling relatives. Unlike tree squirrels, which typically climb trees when threatened, ground squirrels tend to retreat into their burrows for safety. While some ground squirrel species, like the thirteen-lined ground squirrel, exhibit prominent stripes similar to chipmunks, they are generally larger than chipmunks. A notable physical feature is their internal cheek pouches, used to gather and transport food.
Where Ground Squirrels Live
Ground squirrels are found across a wide range of geographical locations, including North America, Eurasia, and Africa, with some species also inhabiting tropical Southeast Asia. They prefer open environments such as grasslands, meadows, and agricultural fields. These rodents are also commonly observed in pastures, golf courses, cemeteries, and parks.
Their habitat choices contrast with the arboreal environments favored by tree squirrels. Ground squirrels can thrive in various elevations, from sea level to high mountainous regions.
What Ground Squirrels Eat
Ground squirrels are primarily omnivores, and their diet adapts to seasonal availability. They consume a wide variety of plant materials, including seeds, nuts, fruits, roots, and grasses. In spring, they often prioritize fresh green vegetation, shifting to seeds as the season progresses and plants dry out. They are also known to gnaw on tree bark and twigs.
Their feeding habits are opportunistic, extending to animal matter when available. This can include insects such as caterpillars, grasshoppers, beetles, and ants. Some species also consume bird eggs, small vertebrates like mice or voles, and carrion.
Their Unique Behaviors
A defining aspect of ground squirrel life is their reliance on elaborate burrow systems. These underground networks provide shelter, a safe place to raise young, and an escape route from predators. Burrow systems can be extensive, featuring multiple entrances, often numbering between 6 and 20, and can extend from 5 to 30 feet in length, typically 2 to 3 feet below the surface. Some burrows can reach depths of 6 feet or more.
Many ground squirrel species undergo periods of dormancy to cope with environmental extremes. During winter, many non-tropical species enter hibernation, a deep sleep where their metabolic rate and body temperature significantly decrease. For instance, the thirteen-lined ground squirrel’s body temperature can drop to just a few degrees above the burrow’s temperature, with its heart rate slowing dramatically. Some species can hibernate for up to nine months, plugging their burrows during this time. In hot, dry conditions, some ground squirrels enter estivation, a summer dormancy, also by plugging their burrows.
Ground squirrels are diurnal, meaning they are active during the day, with peak activity often observed from mid-morning through late afternoon. Their social structures vary, ranging from solitary living to complex colonial systems. They employ various communication methods, including alarm calls, to alert others to potential threats, often standing upright on their hind legs to survey their surroundings. They typically forage close to their burrows, venturing further to find desirable food sources.