Deer, as herbivores, primarily consume plant matter to meet their nutritional needs. While it might seem intuitive that grass forms a significant part of their diet, the reality is more nuanced. This article explores the role of grass in a deer’s diet and highlights other plant materials they consume.
Deer and Grass Consumption
Deer eat grass, but it is not their primary food source. Their four-chambered stomach is adapted for browsing, not extensive grazing. Unlike grazers like cattle with larger rumens for fibrous grass, deer have smaller, less complex gastrointestinal tracts. This means deer require foods that are more easily digestible and higher in quality.
Mature grass contains high cellulose and silica, making nutrient extraction difficult for deer. A deer that subsisted solely on grass would likely face malnutrition. When deer consume grass, they often seek more nutritious forbs or weeds interspersed within grassy areas. They consume young, green, and succulent varieties, which are more digestible.
The Diverse Deer Diet
Deer are classified as browsers, meaning they primarily feed on the leaves, twigs, and buds of woody plants. Their anatomical features, such as a narrow snout and long tongue, allow them to selectively pick specific, nutrient-rich plant parts. Their diet is highly varied and adapts based on seasonal availability and their changing nutritional requirements throughout the year.
Beyond woody browse, deer consume a wide array of other plant materials. Forbs, which are herbaceous broad-leaved plants, constitute a significant portion of their diet, especially during spring and summer when they are abundant and highly digestible. Examples of forbs include clover and alfalfa, which provide essential protein and minerals. Mast, including hard mast like acorns and beechnuts, and soft mast such as berries and apples, becomes an energy source, particularly in the fall. Acorns, rich in fats and carbohydrates, are highly favored, especially white oak acorns due to their lower tannin content.
Deer also consume agricultural crops like corn, soybeans, and wheat, readily utilizing these highly nutritious and palatable sources when available. During winter, when other food sources are scarce, deer rely more heavily on woody browse, including the stems and twigs of shrubs and saplings. They may also turn to evergreen leaves and leftover crops. The overall diet shifts to meet demands for antler growth, fawn development, and fat reserves for colder months.