Each winter, the Division of Fish and Wildlife receives numerous inquiries regarding the feeding of deer and other wildlife. Although everyone wants to help wild animals through the seemingly difficult time of year, New Jerseyans should be reminded that deer are wild animals and have adapted to cope to the sometimes harsh winter weather, including deep snow, cold temperatures and high winds. Deer adapt physiologically as well as behaviorally to the changes of season. In the fall, subcutaneous fat is deposited, and the reddish summer coat is molted for a highly-insulative winter coat. The metabolism of the deer usually decreases during the colder months. To conserve energy, deer limit their feeding to the warmer daylight hours and in general, become less active, particularly during periods of bad weather. Deer may remain bedded down for long periods of time in areas of dense cover without harmful effects.

The Division of Fish and Wildlife strongly encourages New Jerseyans to avoid feeding wildlife during the winter period and throughout the year. Under most conditions winter feeding is of no value in maintaining deer populations during the winter stress period and may be detrimental to both deer and their habitat. Winter feeding concentrates animals, but provides only a portion of their nutritional requirements. The result is increased browsing on preferred native food plants causing a reduction in these food sources and an increased feeding on less nutritious foods. Continued feeding often results in the deterioration of deer range.

Winter deer losses are sometimes increased through feeding by concentrating the animals in a smaller portion of their range than normal. Thus, competition for available food becomes more intense. Fawns may be rebuffed by the strong, more dominant adult animals, and be unable to obtain enough food for maintenance. If food is distributed, it must be spread out over large areas, to allow all of the deer in the herd to feed.

Deer are only able to digest food through a mutually beneficial relationship with the microorganisms in the rumen-reticulem compartment of the stomach. Rapid changes in diet can produce digestive disruptions resulting in death, because the microorganisms are not able to adapt to a sudden change in diet. It is important not to introduce a new food in large quantities to deer. Readily fermentable foods, consumed in large quantity, without adequate microbial adaptation, may result in rumenitis. Emergency feeding often begins too late and fails to prevent deer mortality. The condition of the deer going into the winter is the major factor in determining its ability to survive the winter.