Deer are adaptable herbivores. Their foraging habits are fundamental to their survival and play a significant role in ecosystem health. Deer constantly seek the most nutritious and palatable vegetation available, demonstrating a flexible foraging strategy that allows them to thrive in diverse habitats.
Key Plant Types Consumed by Deer
Deer consume a variety of plant types: browse, forbs, mast, and grasses. Each category provides different nutritional benefits, and their consumption varies based on availability.
Browse refers to the leaves, buds, and tender twigs of woody plants such as trees, shrubs, briars, and vines. This type of forage is a consistent food source for deer throughout the year, becoming particularly important during colder months when other options are scarce. Examples include maple, oak, sumac, viburnum, and dogwood. While browse is a staple, deer select the youngest shoots and leaves, as these offer higher digestible energy.
Forbs are herbaceous, broad-leaved plants, including wildflowers and various “weeds.” These plants are highly digestible and rich in nutrients, making them a preferred food source, especially from late spring through summer. Common examples include clover, alfalfa, goldenrod, aster, ragweed, and pokeweed. Forbs provide essential protein and can be a major component of a deer’s diet when abundant.
Mast includes both soft mast, such as fruits and berries (e.g., apples, grapes, blackberries), and hard mast, which consists of nuts (e.g., acorns, beechnuts, chestnuts). Soft mast offers high sugar and vitamin content, while hard mast provides fats and carbohydrates. Mast is an energy source for deer, particularly in the fall, aiding in fat storage for winter.
Grasses, while less preferred than browse or forbs, are also consumed by deer. They eat tender, new grass shoots, especially during late winter and early spring when cool-season grasses are among the first green forage to appear. However, grasses are less digestible and contain lower nutrient content compared to other plant types. Deer may opportunistically feed on agricultural crops like corn or soybeans when available, as these can be nutritious.
Factors Shaping Deer Dietary Choices
Deer’s dietary choices are dynamic. They are influenced by environmental and physiological factors that determine what plants they consume and when.
Seasonality significantly shapes a deer’s diet, as plant availability and nutritional content change throughout the year. In spring and summer, deer prioritize fresh, green vegetation like tender leaves, young shoots, and forbs, which are rich in nitrogen and easily digestible for growth and recovery. As autumn progresses, their diet shifts to energy-rich mast like acorns and fruits to build fat reserves for winter. During winter, when food sources are scarce, deer rely more heavily on woody browse, twigs, and buds.
Geographic region and habitat directly impact the specific plants available to deer. A deer’s diet can vary widely based on whether they inhabit forests, plains, or mountainous areas, each offering a distinct array of vegetation. For instance, deer in the Texas Hill Country might consume more Live Oak or Mistletoe, while those in other regions rely on different local flora.
Deer instinctively seek plants that provide the necessary nutrients for their physiological needs, including growth, reproduction, and energy. Protein supports body growth, fawn development, and antler growth, with young deer requiring diets high in protein. Carbohydrates and fats, primarily from mast, provide energy, especially during demanding periods like the breeding season or cold weather. Deer also require minerals like calcium and phosphorus; phosphorus can sometimes be a limiting nutrient.
Palatability and availability determine a deer’s diet. Deer are selective foragers, preferring foods that are both appealing to their taste and readily accessible. Their narrow snouts and prehensile tongues allow them to choose specific, desirable plant parts, such as young, tender shoots. When preferred foods become scarce, deer consume less palatable options to meet nutritional requirements in times of limited resources.