Deer are herbivores, meaning their diet consists entirely of plants. These adaptable animals are generalist foragers, consuming a wide variety of vegetation depending on what is available in their environment. The specific foods deer consume are largely influenced by location, season, and nutritional requirements.
Primary Forage: A Herbivore’s Diverse Menu
The primary components of a deer’s diet include leaves, twigs, grasses, forbs, fruits, and nuts. Woody browse (leaves, buds, and twigs from trees, shrubs, and vines) forms a substantial part of their intake. Examples include oak, maple, dogwood, sumac, wild grape, greenbriar, and blackberry. These woody plants are available, particularly during colder months when other food sources are scarce.
Forbs, herbaceous plants, contribute significantly to a deer’s diet, especially during warmer seasons. Forbs are broad-leaved plants like clover, alfalfa, wild lettuce, ragweed, and partridge pea, which are often highly digestible and rich in nutrients. While deer consume some grasses, they prefer younger, greener varieties and do not rely heavily on perennial grasses due to their lower digestibility and nutrient content.
Fruits, nuts, and acorns, collectively known as mast, provide high-energy food sources when they are available. Acorns, particularly from white oaks, are a favored food due to their palatable, sweeter taste and lower tannin content. Other important mast crops include walnuts, hickory nuts, chestnuts, and various berries such as blackberries, raspberries, apples, and wild grapes. These concentrated energy sources are important for deer to build fat reserves.
Seasonal Shifts in Deer Diet
A deer’s diet changes throughout the year, adapting to the availability of food and their varying nutritional demands. In spring, as new growth emerges, deer seek out highly digestible, tender green shoots and emerging forbs. This fresh vegetation helps them recover body weight lost during winter and provides the protein needed for antler growth in males and lactation in females.
During the summer months, deer benefit from an abundance of lush vegetation, including a mix of leaves, grasses, and early ripening fruits. Forbs continue to be a primary food source, offering easily digestible nutrients. As fall approaches, the focus shifts to high-energy foods like acorns, nuts, and ripe fruits. These mast crops are important for deer to accumulate fat reserves in preparation for the rigors of winter and the breeding season.
Winter presents the greatest challenge for deer in finding sufficient food. Their diet shifts to woody browse, consisting of twigs, buds, and bark from trees and shrubs. While less palatable and digestible than summer forage, these woody materials are often the only food available. Deer may also consume dried vegetation and any remaining hard mast found beneath the snow to survive this lean period.
Beyond Plants: Specialized Needs and Occasional Finds
Deer also seek out certain items beyond typical plant matter to meet specific bodily needs. They are frequently drawn to mineral licks, which are natural or man-made deposits providing important minerals. These minerals, including calcium, phosphorus, and sodium, are important for bone development, antler growth in males, and reproductive health in females. Sodium is particularly sought after, especially in spring and summer, to balance deficiencies caused by high water content in fresh forage.
Fungi and lichens are also part of a deer’s diet, particularly when other preferred food sources are scarce. Deer consume various types of mushrooms and lichens, such as “Old man’s beard,” which offer supplemental nutrients. Studies indicate deer can identify and consume certain mushroom varieties that are toxic to humans, suggesting they can discern edible fungi.
Water is obtained not only through direct drinking from puddles, streams, or ponds but also significantly from the moisture content within the plants they consume. This “preformed water” from succulent vegetation can meet a large portion of their hydration needs, especially during seasons when green forage is abundant. Shed antlers, though not a common food source, may be gnawed on by deer and other animals. This behavior provides a source of calcium and other minerals that contribute to their nutritional intake.