The inclination to interact with wildlife, particularly by offering food, is a common human impulse. While this desire often stems from a wish to help or observe animals, feeding deer can introduce various complexities and unintended consequences. Understanding the natural dietary needs of deer and the broader implications of providing supplemental food is important for their well-being.
Natural Deer Diet
Deer are ruminants, with a specialized four-chambered stomach for digesting fibrous plant materials. Their natural diet primarily consists of browse, including leaves, twigs, and shoots of woody plants like dogwood, maple, ash, and birch. They also consume forbs, which are herbaceous flowering plants, and various nuts and acorns in autumn.
The composition of a deer’s diet changes seasonally, reflecting the availability of forage. In winter, their digestive system adapts to process woody browse, using specific microorganisms in their rumen to break down high-fiber content. They conserve energy by reducing activity and drawing on fat reserves accumulated in fall.
Harmful Foods to Avoid
Many human foods and agricultural products harm deer, despite their apparent palatability. Corn, for instance, is a high-carbohydrate, low-fiber food that disrupts a deer’s digestive system. When deer consume large quantities of corn, particularly if unaccustomed to it, it can lead to acidosis (grain overload), where excessive lactic acid production in the rumen lowers pH, damaging the gut lining and impairing nutrient absorption. This can result in severe diarrhea, dehydration, laminitis, and even death, particularly in stressed winter deer.
Hay, often seen as winter feed, is harmful because deer lack the digestive microorganisms to process it, potentially leading to starvation even with a full stomach. Foods like bread, pastries, and nuts or nut mixes often contain sugars, spices, and preservatives that deer cannot easily digest. Large quantities of fruits and garden vegetables can cause digestive upset due to high sugar or unfamiliar composition. Commercial pet foods are unsuitable, formulated for different digestive systems and nutritional needs.
Risks of Supplemental Feeding
Beyond specific harmful foods, supplemental feeding carries broader ecological and behavioral risks. Concentrating deer at feeding sites increases their physical proximity, which can accelerate the transmission of diseases such as Chronic Wasting Disease (CWD) and bovine tuberculosis. CWD, caused by a prion, spreads through direct contact, bodily fluids, and environmental contamination. Tuberculosis transmission is also facilitated by the close contact at feeding sites.
Supplemental feeding can alter deer behavior, leading to habituation to humans. This reduced fear can make deer more prone to injuries from vehicles and increase aggression towards humans when seeking food. Increased deer density around feeding areas can also lead to over-browsing of natural vegetation and ornamental plants, causing significant property damage for homeowners and farmers. Feeding sites can also attract predators like coyotes, raccoons, and skunks, increasing predation risk for deer and other wildlife. The unnatural congregation of deer near roads due to feeding can also contribute to a higher incidence of deer-vehicle collisions, posing risks to both wildlife and human safety.
Safe Feeding Practices
While general supplemental feeding is discouraged due to its risks, there are limited scenarios where it might be considered, such as during extreme winter conditions or for licensed wildlife rehabilitation efforts. Any consideration of feeding deer should begin with consulting local wildlife authorities, as feeding is often regulated or prohibited. In situations where feeding is permitted and deemed necessary, specific guidelines should be followed to minimize negative impacts.
Appropriate food types, if allowed, focus on natural forage supplements or specially formulated deer pellets. These pellets provide a balanced nutritional profile, including adequate protein (12-20%) and minerals like calcium and phosphorus, important for growth. Corn and hay are generally inappropriate for deer. Feeding methods should aim to reduce deer concentration by scattering food widely rather than creating piles, and ensuring access to fresh water is also important. Supplemental feeding should always be a temporary, last-resort measure, never replacing the deer’s reliance on natural foraging.