The major activity for deer in autumn is breeding. During this time deer move considerable distances as part of their breeding behavior and in response to changes in food supplies. Autumn nutrition is important to deer since their physical condition as they approach winter has a strong bearing on their survival. During this period, deer must build fat reserves to help them survive. Fall foods must be abundant and high in nutritional value. Important foods include acorns, beech nuts, crabapples, maple and dogwood leaves, willow, and brambles. Preferred agricultural crops include corn, soybeans, apples, and fall-planted grains such as wheat.
Vegetative cover used during autumn is similar to that used during summer months. Open areas are used during the night, while in daytime brushy areas are preferred. Standing corn is not only a high quality food source, it is also often used during the fall as escape cover, as well as travel and resting sites. Quality fall cover includes cattail swales, standing corn, switchgrass fields, and plantations of young pines 10 to 20 years old.
Winter is the most critical season of the year. Deer mortality can be excessive if food and thermal cover are inadequate. Winter losses in local areas can range from as low as five percent in quality food areas to 50 percent where food resources are severely restricted. Winter mortality depends on winter severity, and quality and quantity of available food.
During winter, protection from the cold and wind is important. Cover can be provided by hardwood and conifer swamps, brushy areas, and dense switchgrass or pines. Swamp conifers and hemlock are important because they help slow the wind and serve as thermal cover. Three to 10 acre dense plantations of spruce or Jack pine, 10 to 25 feet tall, also provide beneficial winter cover.
Important winter food sources include white pine, white cedar, red maple, yellow birch, dogwood, viburnum, sumac, and aspen. Since the major food during this season is woody browse, branches, buds, and leaves must be within reach to provide benefits. These foods are abundant in wooded areas that have had recent logging activity.
Deer movements during the winter months decrease and they may spend most of their time near winter cover. It is important that they find food within one-quarter mile of this cover. In areas of adequate soil quality and growing season length, agricultural crops planted near winter cover are of considerable value.