Squirrels rely heavily on nuts (mast crops) to provide the dense caloric intake necessary for survival, especially during winter months. These small mammals are scatter-hoarders, instinctively burying individual nuts across a wide area to ensure a reliable food source when vegetation is scarce. The high concentration of fats and proteins makes nuts an efficient energy package for building body fat reserves that sustain a squirrel’s fast metabolism.
Native Nuts and Wild Preference
In their natural habitat, squirrels seek nuts that offer the highest nutritional reward. This preference is driven by the need for high-calorie density to fuel their active lifestyle and prepare for harsh weather. Acorns are often the most common mast crop, especially those from white oak trees, which squirrels favor because they contain lower levels of bitter tannins compared to red oak varieties.
Hickory nuts, black walnuts, and pecans are highly prized, delivering high concentrations of fat and protein. These hard-shelled nuts also provide a function beyond nutrition: gnawing through the shell helps wear down a squirrel’s continuously growing incisor teeth, maintaining dental health. Squirrels will expend more energy to crack open these substantial nuts, knowing the caloric payoff is well worth the work.
Safe Preparation for Supplemental Feeding
When offering nuts as a supplemental food source, preparation is important. All nuts should be raw and unsalted to prevent dehydration and kidney stress caused by excess sodium. Nuts offered in their shell are preferable, as they mimic the natural foraging challenge and provide necessary dental exercise.
Common feeder items like peanuts are legumes, not true nuts, and offer a less complete nutritional profile. Peanuts and corn also carry a higher risk of containing aflatoxins, harmful molds that can be toxic to squirrels and affect their liver health. Sunflower seeds are a good source of vitamins but should be offered in moderation due to their high fat content and potential to cause nutritional imbalances.
Nuts and Foods to Avoid
Certain nuts and many processed human foods pose a direct risk and should never be offered to squirrels. Nuts with a poor calcium-to-phosphorus ratio, such as cashews and pine nuts, can be detrimental if consumed in large quantities, potentially leading to Metabolic Bone Disease. This condition causes calcium to be pulled from the bones, leading to fractures and a crippling disorder.
Avoid feeding squirrels highly processed items like cookies, bread, sugary cereals, or candy, as these offer no nutritional value and can cause digestive upset or obesity. Moldy nuts or corn must be discarded immediately, as they can contain fatal aflatoxins. Raw almonds contain minor amounts of cyanide compounds, so it is best to select other varieties for feeding.