Deer are herbivorous mammals, primarily consuming plant matter. Their feeding habits are adaptable, allowing them to thrive in diverse environments. The specific plants they consume vary based on habitat availability, enabling them to meet their nutritional needs.
Primary Food Sources
Deer forage on a range of plant materials, often categorized into main types. Forbs, broad-leaved herbaceous plants, constitute a significant portion of their diet, especially during warmer months. Examples include clover, alfalfa, and various wildflowers.
Browse, consisting of leaves, twigs, and shoots from woody plants, becomes increasingly important when other food sources are scarce. Deer consume tender growth from species like maple, oak, and dogwood. While less significant than forbs and browse, grasses are also eaten, particularly new, tender growth in spring.
Fruits and nuts, collectively known as mast, offer concentrated energy and nutrients, especially important in late summer and fall. This includes hard mast like acorns and beechnuts, as well as soft mast such as wild berries, apples, and persimmons. Additionally, deer may consume fungi, including mushrooms, when available.
Seasonal Dietary Changes
A deer’s diet undergoes significant changes throughout the year, driven by plant availability and shifting nutritional requirements. In spring, as new vegetation emerges, deer focus on tender, highly digestible new growth. This includes succulent forbs and fresh shoots of woody plants, which provide a burst of protein and energy after winter.
During summer, lush vegetation allows deer to consume a wide variety of plants. They graze on forbs and browse, and as fruits ripen, soft mast becomes a valuable diet component. This rich food availability is crucial for building fat reserves before colder seasons.
As fall arrives, deer shift their focus to foods high in carbohydrates and fats, preparing for winter months. Hard mast, such as acorns and chestnuts, becomes a primary food source due to its high energy content. They also consume seeds and remaining fruits, which help them accumulate energy for survival.
Winter presents the greatest challenge, with food availability significantly reduced. During this time, deer rely heavily on woody browse, consuming dormant twigs, buds, and the bark of trees and shrubs. They also scrape for any remaining dead leaves or dried vegetation under the snow.
Foods to Avoid
While deer are adaptable eaters, certain foods, particularly those provided by humans, can be detrimental to their health. Processed human foods, such as bread, crackers, and corn, lack the necessary nutrients and can cause severe digestive upset. Their specialized digestive systems are not equipped to process these types of food, leading to issues like acidosis, which can be fatal.
Ornamental plants in gardens can also pose a risk. Certain species, including azaleas, rhododendrons, and yew, contain compounds toxic to deer. Even non-toxic garden plants, if consumed in large quantities, can disrupt a deer’s natural foraging patterns and lead to nutritional deficiencies.
Feeding wild deer can also habituate them to human presence, leading to increased human-wildlife conflicts. It can also concentrate deer in unnaturally high densities, facilitating the spread of diseases within the population. For these reasons, it is best to avoid feeding wild deer any food.