When we experience an especially harsh winter, many people worry about how deer are coping. From the warmth of our homes and the daily routine of feeding domestic stock and pets, it is often assumed that we can and should help deer survive the rigors of winter by feeding them.
Deer have several natural adaptations that help them survive winter. These include a thick winter coat of hollow hair and the storage of fat through summer/fall for use during the winter. Deer also go to 'yards' during the deep snow period of winter. Yards are areas that offer the ability to move about easily because of reduced snow levels, while providing shelter and a nearby source of food. These yards are generally coniferous forests with a closed canopy which breaks the wind and helps intercept snow. Deer develop a network of trails within these yards as they travel to and from feeding. Throughout winter they keep the trails open for easy travel and greater ability to escape predators. As well, when deer are grouped together, many eyes, ears and noses are very effective in detecting predators.
Deer have also adapted to our northern climate by reducing their activity during January - February. Their overall metabolism actually slows down so they require less food - much like turning the thermostat down. However, despite these adaptations, adult deer routinely lose up to 20% of body weight during winter, regardless of the amount or quality of food present.
That is not to say that winter is not a problem to deer. On the contrary, each year a portion of the provincial deer herd will not survive winter, usually due to starvation. Snow not only covers much of their food (grasses, forbes, leaves and low shrubs) but their ability to move about becomes severely restricted when their sinking depth in snow reaches about 50 cm. The first animals to succumb to the rigors of winter are generally fawns and yearlings (which have little fat reserve to fall back on) and the old or sick. The amount of starvation depends on the severity of winter, quality of winter range and the number of deer competing for food in any given area.
A deer herd's ability to survive winter depends on several factors. First, the condition of deer going into winter is important. The amount of stored fat is a measure of energy available to draw on during winter. Then the severity of winter weather (duration of cold weather and depth of snow) will determine how much energy is needed. As well, stress through disturbance caused by humans, dogs or predators will use energy reserves, and finally, the amount of food available through winter. Together, these factors will determine if a deer will starve or survive. A very long and cold winter with persistent deep snow, will cause exhaustion of fat reserves and together with the lack of accessible food… the result may be starvation and eventually death.
When winter has become severe, people often consider giving supplementary feed to deer. The issue of winter-feeding is not only a question of whether to feed deer or not, but one must consider when to feed, what and how to feed, and the costs and benefits of doing so. It must be done properly. The wrong method can harm or even kill deer.
Problems with Feeding Deer in Winter:
- First we must ask ourselves, "If we are successful in feeding deer properly, and as a result more deer survive the winter in good shape and give birth to healthy and strong fawns, what will the situation be next winter?" Eventually deer numbers will exceed the carrying capacity of the natural habitat and more deer will be dependant on our handouts. Can we keep the feeding program going at greater capacity each year?
- Even though fed, deer will continue to browse on nearby natural foods. Eventually most natural browse in the area will be eliminated. The same site will have very little natural food to offer the following year.
- Concentrating deer around feeders near our homes, may cause a number of problems. Property damage in the area may increase by their browsing on ornamental shrubs and trees. They may become a hazard to local traffic as they move to and from the feeding site. Domestic dogs will begin chasing and even killing deer.
- Deer are more vulnerable to coyotes during deep snow periods. If deer concentrate at a supplementary feeding site that is not associated with adequate cover and opportunities to escape predators, they may be more easily taken by coyotes.
- Deer that are concentrated, regardless of snow depth, are more susceptible to disease.
- Improper diets are often fed. These lead to digestive upset and potentially death.
- If not enough food is provided or if it is not distributed properly, aggression and fighting will occur at the feeding site. Most often it will be the deer that need the feed most that will get the least.
The Advantage of Feeding Deer:
First we must ask ourselves, "Why do we want to feed deer?" If it is to make ourselves feel good or to see more deer from our kitchen window, perhaps we should reconsider. These are reasons for our benefit, not necessarily for the benefit of deer.
The main reason for feeding deer is to prevent a large die-off due to starvation.
Further, if deer make it to spring in relatively good condition, they are more likely to give birth to strong and healthy fawns with an increased chance of survival.
How to Properly Feed Deer:
A proper feeding program requires the following essential elements:
- An efficient delivery system to get food to deer on an established trail network,
- A method to deliver the food until the end of winter, and
- An adequate supply of the right type of food.
Where to Feed:
First, make sure you have landowner permission before initiating any feeding program.
Deer must have good quality cover in close proximity to where the food is delivered. It may be tempting to feed them where it is most convenient or entertaining for ourselves. However, the wrong location could result in more harm than good.
Find where the deer are and what areas they are using as cover. This will likely mean using a snowmobile or walking with snowshoes. Remember, your searching may disturb and stress them which uses energy reserves.
If you don't find their network of trails, pack trails with snowshoes allowing the deer to approach and leave the feeding site from many directions.
What To Feed:
Natural winter food for deer consists primarily of woody browse from hardwood twigs and occasionally needles of balsam fir. The most preferred browse species include: sugar, red, mountain and striped maple; yellow and white birch, witch and beaked hazel and red oak.
Deer have problems with many diets that livestock consume easily. Deer depend on a variety of bacteria and microorganisms in their rumen (stomach) to break down food. A change in diet requires a change in the population of these microorganisms to process the new food properly. Other problems such as "acidosis" (excess acid buildup in the rumen) and scours (diarrhea) may occur if they are given cereal grains. It is therefore important to gradually introduce artificial feed in an area where natural food is also available.
1. Natural Food. If possible, it is best to feed natural food. To do this, cut down a few of the preferred hardwood trees mentioned above. Again, make a number of trails from the new feed to their cover area. Check these trees every few days and turn them so all the branches can be used. The number of trees needed and when to provide more will depend on how many deer there are in the area. In the spring/summer, you can return and cut the same trees for firewood. By doing this you are not only immediately providing food to the deer, but over the next few years a large number of suckers will grow from the stumps and other shrubs and saplings will grow in the clearing you have created. Both short term and long term feeding is accomplished.
2. Deer Pellets. Most farm feed outlets carry a specially formulated ration for deer or can tell you where it can be bought. This feed is specially formulated for deer with consideration of their energy, protein and fiber needs, as well as digestibility. At first deer may not recognize these pellets as food but if introduced with small amounts of corn, oats or alfalfa, they will gradually become accustomed to the new food.
3. Cereal Grains. Although not as well balanced a diet as Deer Pellets, rolled oats or coarsely milled oats are easily digested and reduce the possibility of problems associated with a sudden diet change. Whole corn and whole oats can also be used and are often readily available. A ratio of 1:1 to 1:4 corn:oats is recommended.
Avoid feeding pure corn, barley or wheat as they are too high in starch and may cause digestive problems leading to death.
As with pellets, these foods can be placed in handful amounts on well packed snow… preferably under conifer trees to prevent being covered with snow. Once the deer have become accustomed to this type of feed, it can be delivered by laying feed bags on the ground and cutting a large panel out on the top side. This will keep the feed together and off the ground, reducing waste. Hoppers like those used to feed domestic cattle or sheep, may also be used.
4. Hay or Alfalfa. Caution should be used when feeding hay or alfalfa as deer (especially when in starved condition) may have problems digesting them. Introduce this feed gradually and ensure natural foods are also available.
5. Fruit & Vegetables. Although deer will eat apples, carrots, cabbage, etc., their use is not recommended. They are like candy to a child… tasty but of little value in providing a well-balanced and nutritious diet.
As can be seen, feeding is not just a matter of throwing a few bread crusts off the back porch. If you want to feed deer effectively (to their benefit) ensure you do it properly with the energy and resources to continue until the end of winter.
- Start early in winter to allow deer the ability to find and become accustomed to the new feed and for their rumen microorganisms to adjust.
- Use the same feed throughout winter.
- Provide food at a number of locations to ensure all have a chance to feed. This will also minimize aggression.
- Keep the feed dry if using pellets or cereal grains. Wet feed will likely not be consumed.
- Ensure a constant supply of feed is provided. Check after each snowfall that the feed is not covered.
- Increase the amount of feed available in late winter when need is the greatest and activity levels have increased.
- As spring approaches and snow is no longer deep, or if deer are no longer coming to the site, feeding should be discontinued.
For more information on feeding deer in winter or woodlot management for the benefit of deer and other wildlife, contact the Department of Natural Resources Wildlife Biologist for your area.