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Brining Science to the Adirondacks and the Adirondacks to Science

Feeding Adirondack Deer in Winter

Let's Understand What We're Doing

Interest in winter deer feeding programs in the Adirondack region of northern New York has expanded dramatically in recent years, particularly among sportsmen groups. Such programs are appealing to sportsmen for a variety of reasons, but have been met with some disdain by game management agencies and wildlife biologists.

The question of whether “to feed” or “not to feed” is not the primary concern of this discussion. What is addressed here is that once the decision is made to feed deer, let's know what we are doing, and lets be realistic about our “expectations.” In order to achieve these goals, it is important to understand several critical components of deer biology and behavior. Each of these key factors of deer biology and behavior are addressed below, followed by an interpretation of how they relate to a winter deer feeding program. Deer in winter

White-tailed deer have developed numerous biological and behavior adaptations to combat the severe winters of the Adirondacks. Biological adaptations include the development of a thick winter coat of hollow hairs to insulate their body against heat loss and a lowered basal metabolic rate (by about 40%). They build body fat on summer/fall range which serves as both added insulation and an energy reserve to help them through the winter (as much as 1/3 of their winter energy needs are met by “using” stored body fat). Deer will normally decrease their food intake during winter and may commonly lose up to 15-30% of their body weight (even deer held in pens with access to unlimited quantities of nutritious food).

Deer are less active in winter, thereby conserving energy. In addition, most deer in the Adirondacks move long distances (5-15 miles) from summer range to winter range (typically dense, lowland conifer forests). Deer concentrate in these conifer areas (deer yards) where snow depths are reduced, temperatures and wind conditions are less severe, and collectively they can develop and maintain trails through the snow where travel is easier and escape from predators is enhanced. All of these behavioral adaptations are designed to conserve energy during the winter period.

By their very nature, the dense, lowland conifer areas selected by deer as winter concentration areas are poor producers of deer browse. These conifer forests are typically found on shallow, poorly drained, and relatively infertile soils limiting productivity. The very same overhead conifer foliage which provides the shelter sought by deer, severely restricts the amount of sunlight reaching the forest floor, thus limiting the development of plants available to hungry, wintering deer. Several studies have shown that the digestibility of even “preferred” winter deer browse species is extremely low (< 50%), and the amount of energy expended foraging in deep snow is extremely high, almost a “no win” situation for wintering white-tails.

As a result of these limitations, it is extremely important that deer enter the winter period in the best physical condition possible. This means developing critical fat reserves on high quality summer/fall range before moving into yarding areas. Ultimately, winter survival of white-tailed deer in the Adirondacks is a reflection of the habitat quality of both the summer and winter ranges used by these animals.

What does this mean to a winter deer feeding program?

Deer should be fed in areas where they normally congregate during the winter period. Do not expect deer to move long distances away from their traditional wintering area even when abundant food is supplied.
The duration of the winter confinement period (time deer are in yarding areas) can vary dramatically from year to year in the Adirondacks. In general, most deer will begin to arrive on winter range when snow depths approach 12-15 inches. Deer will stay on winter range until snow depths fall below this same level in spring. Over the last 45 years this period has averaged 83 days in the central Adirondacks. In 1970-71 it lasted 131 days, while in 1979-80 only 4 days. A sound winter deer feeding program should plan (budget) to feed deer on the basis of an average winter, but should be prepared financially to feed throughout an extended winter when the need is greatest. Keep in mind the fact that some deer are lost even during “average” Adirondack winters. In general, any winter confinement period that lasts longer than 60 days places severe stress on deer, particularly fawns.
Most of the deer using a particular wintering area have come from areas of summer/fall range many miles away. As a result, many of the deer you are feeding probably do not reside on your land but some other ownership during the summer and fall seasons. In other words, it is quite likely you are feeding deer that you will not have access to during the fall hunting season. This is an important point to remember if having “more deer to hunt” is your primary reason for feeding deer.
When deer congregate in winter, local densities can be very high (up to 100+ deer/sq. mi.). High deer densities can cause problems. Deer will continue to eat natural vegetation in and around a supplemental feeding station. They may destroy tree regeneration, shrubbery, or other vegetation important to the landowner.
There is no direct evidence to support the contention that the spread of disease or rate of depredation is higher in free-ranging deer herds associated with winter feeding programs. Remember, deer are already highly concentrated in wintering areas as a result of their own natural behavior patterns.

Another aspect of deer behavior that can play a significant role in a winter deer feeding program is related to the social hierarchy that exists within groups of deer.

The dominance of one animal over another often determines “who gets what resources first.” In general, adult animals are dominant over yearlings and fawns, yearlings are dominant over fawns, and fawns are “low man on the totem pole.” The expression of dominance generally takes the form of varying degrees of aggressive behavior between individuals. Such aggression is most likely to occur during the breeding season, or when resources are in short supply and deer are aggregated. This certainly pertains to wintering deer in the Adirondacks, and is directly applicable to the conditions associated with a winter deer feeding program.

What does this mean to a winter deer feeding program?

As a result of this aggressive behavior, supplemental food made available through a winter deer feeding program will not be shared equally among all the deer the program intends to serve. In particular, fawns, which have the greatest need, generally receive the least benefit. Fawns are especially vulnerable to the hardships imposed by Adirondack winters. These animals have directed their energy into growth throughout the entire summer and fall seasons, and as a result have accumulated little in the way of fat reserves.
Although this problem cannot be overcome completely, distributing supplemental food to several locations within the feeding site (even if only 15-20 yards apart) increases the opportunity for several animals to access food simultaneously. Putting out more food than necessary increases costs and probably only makes the dominant deer “happier.”

White-tailed deer are ruminants. In addition to having a four-part stomach, their ability to digest food depends in part on the presence of a variety of bacteria and protozoans (microorganisms) present in their stomach (rumen). These microorganisms play a major role in breaking down the variety of plant material (particularly woody material) ingested by the deer. Different types of microorganisms within the digestive tract have the ability to break down different kinds of food. When the diet of a deer changes dramatically, it may take 2-3 weeks for the microorganism populations in the rumen to adjust to properly process the new food material so it can be useful to the animal.

What does this mean to a winter deer feeding program?

Select the correct feed and use the same kind of feed throughout the winter.
Provide the appropriate amount of feed on a daily basis (not intermittently), preferably at the same time of day.
Provide feed throughout the entire winter period, not just “when times get tough” in March and April.

What to feed?

The choice of an appropriate feed is a prerequisite to a successful winter deer feeding program. Two basic requirements of deer must be met by the food provided; energy needs and protein needs. As an example, the average daily energy and protein requirements for a 130 lb. Deer (live weight) are presented below.

Energy required (KCAL/day) = 2500

Protein required (grams/day) = 96.7

A third factor that has to be taken into consideration when evaluating a potential deer feed is its digestibility (the percent of usable energy or protein which a deer can get from the feed it ingests). Digestibility varies considerably between different feeds as shown below for corn and “Agway Deer Feed”, a commercially prepared pelleted ration.

	Feed Composition		Digestibility
	Gross Energy (KCAL/Kg)	Protein (Grams/100g)	Dry Matter (%)	Protein (%)
Corn (whole)	4500	8.5	87	77
Deer Feed	4500	15.4	75	96

Using the information presented in the table above, the approximate number of pounds of these feeds required per day by a 130 lb. Deer to meet its requirements would be:

	Energy	Protein
Corn (whole)	1.40 lbs. (636 grams)	3.25 lbs. (1476 grams)
Deer Feed	1.63 lbs. (740 grams)	1.44 lbs. (654 grams)

In summary, the Deer Feed ration constitutes a fairly balanced diet for deer. An average size animals could meet both its energy and protein requirements by eating about 1.6 lbs. per day. Corn on the other hand is relatively low in protein, requiring an average deer to eat approximately 3 1/4 lbs. Of corn daily to meet its protein needs. This would increase costs significantly. Corn is also low in fiber (which in part accounts for its higher dry matter digestibility). Deer need a high fiber diet for proper rumen function as they are used to eating woody material. As a result, they would probably need to supplement their diet with natural browse (if available) in addition to corn. Corn should not be the only item used in a winter feeding program for deer because of these factors. It could, however, be used as a supplement with appropriate commercial rations as an extra energy source.

Costs of a winter deer feeding program:

In addition to the time involved, which can be considerable depending on the particular situation, the actual costs associated with a winter deer feeding program are an important consideration.

Since most of the labor involved usually takes the form of volunteer help, no costs are associated with this part of the program in the example shown below. Thus, the cost of feed, the amount provided per deer, the number of deer being fed, and the length of the winter become the primary factors affecting the cost of a winter deer feeding program.

Example:

Feed : Agway Deer Feed @ $.1498/lb. ($14.98/100 lb. bag)
(For comparative purposes whole corn costs ($11.98/100 lb. bag)
Amount of feed per deer = 1.6 lbs./day
Average number of deer being fed = 50
Average length of Adirondack winter = 83 days

Calculations:

1.6 lbs. X 50 deer X 83 days = 6640 lbs. of feed required
6640 lbs. of feed X $0.1498/lb. = $994.67

The total cost (exclusive of labor) of this winter deer feeding program would be about $995. A similar program using only corn (at 3.25 lbs./day) to meet protein requirements would cost about $1616. Keep in mind, these figures represent costs during an average Adirondack winter, and are probably somewhat conservative as they do not account for feed that is lost in the snow or eaten by birds and other animals (which may amount to as much as 10% of the total). Furthermore, it is unrealistic to assume a deer will eat his or her “fair share” of feed, and move on. Studies have shown that when feed is provided ad libitum (unrestricted supply), average consumption may exceed 2.25 lbs./animal/day.

Remember also, a new deer feeding program is likely to take a while to develop, with the number of deer increasing over the course of the feeding season, and from year to year. Thus, it is important for the sponsor to take this into account when planning and budgeting for such a program.

In conclusion, operating a winter deer feeding program represents a substantial financial investment, and requires a sincere commitment on the part of the sponsor. A casual approach provides little, if any, benefit to the deer. A program carried out correctly will undoubtedly benefit some deer on a local scale. However, when considering the entire Adirondack deer population, estimated at 75,000 animals, the overall impact of winter feed programs on the well-being of this herd is minimal. In all likelihood, the unpredictable nature of Adirondack winters will continue to periodically take heavy tolls on this population in spite of winter feeding programs. Unquestionably, the personal satisfaction, increased understanding of nature, and enjoyment of watching deer gained by the sponsor will in the long run be the greatest positive benefit derived from a winter deer feeding program.

Prepared as a public service project by Richard W. Sage, Jr. and Kent A. Gustafson. Copies of this publication may be obtained by writing the Office of News and Publications, Room 122 Bray Hall, SUNY-ESF, 1 Forestry Drive, Syracuse, NY 13210 or phoning (315) 470-6644.