Squirrels can and frequently do eat corn on the cob, especially when it is readily available in suburban gardens or feeding stations. Corn is a common, high-calorie food source that squirrels are strongly attracted to. However, just because they enjoy eating it does not mean it forms a healthy part of their regular diet. The widespread availability of corn as a supplemental feed introduces nutritional imbalances and health risks for wild populations.
The Nutritional Reality of Corn
Corn kernels are primarily composed of carbohydrates, specifically starch and sugar, providing a burst of energy but lacking essential nutrients. This high concentration of starch gives corn a high glycemic load, which can contribute to weight gain and obesity if consumed excessively. When corn becomes a staple, it displaces other foods that provide the necessary proteins, vitamins, and minerals for long-term health.
A significant concern with a corn-heavy diet is the severely unbalanced ratio of calcium to phosphorus found in the grain. Squirrels require a dietary calcium-to-phosphorus ratio of approximately 2:1 for proper bone health, but corn presents an inverted ratio of about 1:45. This imbalance causes the body to pull calcium from the bones to balance the excess phosphorus. This can lead to Metabolic Bone Disease (MBD), which results in weakened bones and neurological issues, often proving fatal.
Beyond the nutritional imbalance, corn carries a risk of contamination from Aflatoxins, which are highly toxic compounds produced by the Aspergillus fungus. This mold growth occurs on kernels stressed by drought, heat, or insect damage, and increases rapidly in warm, moist storage conditions. Aflatoxins are carcinogenic and can cause acute toxicity, leading to liver damage, immune suppression, and death. Even corn that appears visually clean may harbor dangerous levels of these toxins, making the consumption of improperly stored corn a gamble for wildlife.
How Squirrels Consume Corn on the Cob
When presented with corn on the cob, a squirrel’s immediate goal is to remove the kernels quickly and efficiently. They use their specialized, ever-growing incisors to gnaw across the rows, shucking the kernels from the cob. This is often a rapid process because they are hardwired to gather food for caching, minimizing exposure to predators.
Whole, dried field corn, often called ear corn, is common in feeders because it is a substantial, less perishable food source than fresh sweet corn. Once the kernels are removed, squirrels either consume them immediately or carry them off to bury for later use. This caching behavior helps sustain them through periods when food is scarce.
After the kernels are stripped, the fibrous cob itself is sometimes handled by the squirrel, though it offers little nutritional value. Some squirrels chew on the empty cob, which may serve as a natural way to file down their continually growing teeth. Leaving empty cobs in the environment is not a cause for concern, as they are discarded or used for gnawing, not consumed for sustenance.
Providing Healthier Food Alternatives
Given the nutritional deficiencies and the risk of Aflatoxin contamination associated with corn, it is better to offer healthier alternatives to squirrels. The most beneficial foods mimic a squirrel’s natural diet while providing a balanced nutrient profile. Recommended options include specialized rodent blocks, which are commercially formulated to provide the correct calcium-to-phosphorus ratio and complete nutrition.
Unsalted, in-shell nuts are excellent choices because they require gnawing, which aids in dental maintenance. Certain fresh vegetables, such as leafy greens, broccoli, and zucchini, can also be offered in small amounts to provide vitamins and hydration. The goal of a responsible feeding program is to provide variety and moderation, ensuring no single food item dominates the diet.
To minimize the risk of disease, any food offered must be fresh, clean, and replaced frequently. Feeders should be kept dry and cleaned regularly to prevent mold growth, which is the precursor to Aflatoxin contamination. Providing a consistent source of clean water is also helpful, as squirrels need daily hydration, especially when consuming dry foods.