Squirrels are a common sight, often observed burying or consuming seeds and nuts, leading many to wonder what food they consider the ultimate prize. These rodents are classified as opportunistic omnivores, meaning their diet is quite diverse, yet they consistently prioritize foods that offer the highest return on energy investment. Their continuous foraging behavior is driven by the need to maintain a high metabolism and prepare for periods of scarcity, such as winter. The core of their diet relies on specific, high-energy sources that fuel their acrobatic lifestyle and ensure long-term survival.
The Top Contenders: Preferred Nuts
When given a choice, squirrels consistently select true nuts dense with calories and easily digestible fats. Favorites include black walnuts, pecans, and hickory nuts, all prized for their concentrated energy content. Black walnuts have a tough shell that only the strongest jaws can crack, but the rich, oily reward inside makes the effort worthwhile. Pecans offer a softer shell than walnuts and provide healthy fats and protein.
Although acorns are a common and abundant food source, squirrels often treat them as a secondary option compared to oilier true nuts. This is because acorns, especially those from red oak trees, contain high levels of bitter tannins that interfere with protein digestion. Squirrels preferentially eat low-tannin white oak acorns immediately. High-tannin red oak acorns are frequently buried and stored, allowing water to leach out the bitter tannins over time, which reveals a distinct preference for maximum caloric gain.
Nutritional Drivers of Squirrel Preference
The preference for certain nuts is driven by nutritional density, not flavor alone. High-fat nuts provide the concentrated energy necessary for a squirrel’s active life, including constant movement, climbing, and caching food. Fats, such as Omega-3 fatty acids, are essential for maintaining a healthy cardiovascular system and brain function, which aids the memory needed to recall thousands of buried caches.
Protein is necessary for muscle maintenance, fur health, and general physical strength. The high caloric density of preferred nuts allows the squirrel to quickly build up fat reserves, which are vital for surviving cold winter months when foraging is limited. This need for concentrated energy increases significantly during autumn preparation and during the breeding season to support reproduction.
Beyond Nuts: The Varied Squirrel Diet
While nuts form a significant part of their diet, squirrels are not strict nut-eaters and rely on a diverse range of foods to meet their micronutrient needs. Their omnivorous diet includes plant materials like tree buds, bark, flowers, and sap, which provide fiber and minerals often lacking in nuts. They also consume fungi, seeds, and fresh fruits and vegetables when available, ensuring a broad spectrum of vitamins.
Squirrels actively seek out animal protein, particularly during the spring when food is scarce and protein requirements are high. This includes consuming insects such as caterpillars and beetles, and bird eggs found in nests. Furthermore, squirrels sometimes gnaw on bones and deer antlers, a behavior driven by the need to obtain calcium to counteract dietary imbalances and maintain strong bones and teeth.
Safe Feeding Practices for Backyard Squirrels
To supplement the diet of backyard squirrels, provide foods that mimic their natural, high-quality choices. Unsalted, raw nuts, such as walnuts, pecans, or hazelnuts, are the best options. Offering nuts in the shell provides the added benefit of dental exercise and mental stimulation. Never offer salted or roasted nuts, as the high sodium and altered nutrient structure can be harmful to their health.
Many common human-provided foods should be avoided, even if squirrels readily eat them. Peanuts, which are legumes, are nutritionally poor compared to true nuts and can sometimes harbor a toxic mold that is dangerous to squirrels. Similarly, dried corn is low in nutrition and high in phosphorus, which can interfere with calcium absorption and lead to metabolic bone disease (MBD).