Ground squirrels are common rodents found across various habitats. Understanding their diet is important for appreciating their ecological role and engaging with them responsibly.
Natural Foods
Ground squirrels are omnivorous, consuming a wide array of plant materials and, opportunistically, animal matter. Their plant-based diet includes seeds, nuts, fruits, and vegetative parts of plants such as leaves, stems, roots, and flowers. Specific fruits like almonds, apples, apricots, peaches, and walnuts are readily consumed. They also eat grasses and forbs, which constitute a significant portion of their diet.
Beyond plant matter, ground squirrels supplement their diet with animal protein. This includes various insects like caterpillars, grasshoppers, crickets, beetles, ants, and earthworms. They may also prey on small vertebrates, such as toads, frogs, mice, and even smaller ground squirrels. Ground squirrels are also known to consume bird eggs, hatchlings, and carrion. Recent observations have documented California ground squirrels actively hunting and eating voles.
Seasonal Variations and Foraging
A ground squirrel’s diet changes throughout the year, adapting to the seasonal availability of food sources. In spring, after emerging from hibernation, they primarily focus on fresh green grasses and herbaceous plants, which are abundant. As the warmer months progress and green vegetation becomes less plentiful, their diet shifts. They then transition to consuming more seeds and fruits, which ripen in late summer and fall.
Ground squirrels employ specific foraging strategies to secure food. They often forage close to their burrows but will venture further for desirable food items. One behavior is “scatter hoarding,” where they collect and bury individual nuts or seeds in numerous dispersed locations. This caching strategy helps them secure food for periods of scarcity, especially during winter months. They possess spatial memory and utilize scent cues to relocate their hidden caches.
Foods to Avoid
It is not advisable to feed ground squirrels human foods, as these can be detrimental to their health and alter their natural behaviors. Processed foods like chips, crackers, and bread offer little nutritional value and can lead to digestive issues or malnourishment. Sugary items such as candy, sugary drinks, and certain cereals can cause dehydration and other health complications due to their inability to properly digest large amounts of glucose.
Salty snacks, including salted nuts and pretzels, should be avoided, as excessive salt can lead to dehydration and kidney problems. Certain foods are directly toxic; chocolate contains theobromine, which can cause severe heart problems and seizures, while avocados contain persin, which can induce vomiting and diarrhea. Other harmful items include onions, garlic, dairy products, and raw red kidney beans. While ground squirrels may eat peanuts, they offer poor nutritional value and raw peanuts can contain mold. Complete avoidance of human foods is ideal.