Deer are a common sight in many areas, often venturing into human-populated spaces. This frequent proximity can lead to a natural inclination for people to offer them food. Understanding the specific dietary needs of deer is important, as improper feeding can lead to negative consequences for their health and well-being.
Natural Deer Diet
Deer are herbivores that primarily browse, consuming parts of woody vegetation rather than grazing on grasses. Their diet is highly adaptable and changes with the seasons and available forage. In spring and summer, deer prefer tender green forage, including forbs, new growth of trees, shrubs, and soft fruits. This period allows them to regain weight lost during winter.
As colder weather approaches, deer shift their diet to include more woody browse, twigs, buds, and hard mast like acorns and other nuts. Acorns, beechnuts, and chestnuts are rich in carbohydrates and fats, providing energy for autumn and winter. While deer can consume a wide variety of plants, the majority of their diet comes from a smaller number of preferred forages, such as browse, forbs, and mast. Their digestive system, with its four stomach compartments, is specialized to break down these fibrous plant materials.
Safe Supplemental Options
Providing supplemental food to deer should be approached with caution and in limited quantities. If one chooses to offer food, it should ideally mimic their natural diet and be introduced gradually. Oats are a suitable supplemental food, offering a healthy mix of fiber and carbohydrates that are easily digestible for deer.
Certain fruits and vegetables, such as apples, grapes, cherries, pears, carrots, and snap peas, are consumed by deer in nature and can be offered in moderation. Acorns are a safe and natural food source, enjoyed by deer in the fall and winter. Some commercial deer feeds are formulated to meet their nutritional needs, with a protein content ranging from 12% to 20%.
Harmful Foods and Practices
Many common human foods are detrimental or even toxic to deer, primarily due to their specialized digestive systems. Foods high in carbohydrates, such as corn, bread, and other processed items, can be dangerous if introduced suddenly or in large quantities. Deer stomachs contain specific microorganisms adapted to their high-fiber diet; a sudden carbohydrate influx disrupts this balance, causing acidosis. Acidosis, a lactic acid buildup, can cause bloating, diarrhea, and even death, despite a full stomach.
Bread offers little nutritional value and is hard to digest, causing upset and leading to overeating without nutrients. Other harmful items include sugary foods, meat, dairy products, and certain plants like rhubarb and jimsonweed. Leaving large food piles is harmful, encouraging overconsumption, rapid spoilage, and increased risk of digestive issues and disease transmission.
Broader Implications of Artificial Feeding
Beyond the direct harm from improper food, artificial feeding of deer carries wider ecological and behavioral consequences. Feeding habituates deer to humans, causing loss of natural fear and potential aggression, especially from males during breeding season. This reduced wariness also increases vulnerability to vehicle collisions as they frequent roadsides for food.
Artificial feeding sites concentrate deer in unnaturally high numbers, which increases the risk of disease transmission. Diseases like CWD, bovine tuberculosis, and parasites spread easily through direct contact or contaminated feed and soil at communal feeding spots. Congregation alters natural migration and foraging patterns, drawing deer from wintering areas and causing them to expend more energy traveling to feed sites. Reliance on human-provided food can lead to nutritional deficiencies if it displaces their natural diet, weakening deer and making them susceptible to starvation even with full stomachs.