Milkweed plants frequently spark curiosity among gardeners and wildlife enthusiasts. A common question is whether squirrels consume this plant. Understanding this relationship involves exploring their dietary habits and the plant’s natural defenses.
Squirrels and Milkweed Consumption
Squirrels generally avoid eating milkweed plants. While occasional reports exist of squirrels nibbling on buds or stalks, this behavior is uncommon, primarily due to the plant’s inherent toxicity. Milkweed contains compounds unpalatable and harmful to most animals, deterring consumption. Squirrels typically bypass milkweed in favor of safer food sources, a natural aversion that helps protect the plant from generalist herbivores.
Reasons Squirrels Avoid Milkweed
Milkweed plants contain toxic cardiac glycosides, specifically cardenolides, present throughout the plant, including its leaves and milky sap. When ingested, cardenolides can interfere with heart function and other bodily systems in many animals. These compounds also impart a bitter taste, making milkweed highly unappetizing to most herbivores, including squirrels. The combination of bitterness and poisoning risk acts as a robust natural defense. While some animals, like monarch butterfly caterpillars, have evolved to tolerate these toxins, squirrels have not.
Typical Squirrel Diet
Squirrels are opportunistic omnivores; their diet is diverse and changes with the seasons. Their primary food sources include nuts like acorns, walnuts, pecans, and hickory nuts, which they often bury for later consumption. Seeds are also a significant part of their diet, including sunflower seeds and various tree seeds. Beyond nuts and seeds, squirrels consume fruits such as apples, berries, and grapes, along with vegetables like carrots and leafy greens, and forage for fungi, tree buds, and bark. Occasionally, squirrels may supplement their plant-based diet with insects or bird eggs, especially when other food sources are scarce.
The Ecological Importance of Milkweed
Milkweed plays an important role in supporting biodiversity, especially for the monarch butterfly. It is the sole host plant for monarch butterfly caterpillars; adult monarchs lay their eggs exclusively on milkweed leaves. Caterpillars then feed on these leaves, essential for their growth and development. The cardenolides absorbed by monarch caterpillars make them and the adult butterflies toxic to many predators, providing a crucial defense. Beyond monarchs, milkweed flowers provide nectar for a wide array of other pollinators, including various bees and other butterfly species. Its presence helps support a healthy ecosystem, contributing to the food web for many invertebrates and indirectly for other wildlife.