What Can I Do to Improve Habitat Quality?

Deer have a home range within which they strive to meet all of their habitat requirements. For the most part, studies have found that the home range for a deer encompasses about a square mile – 640 acres. A general law of minimums limits the ability of deer to use fully their habitat. In the case of food, deer benefit from a diversity of plants in different development stages. For example, in winter and spring woody browse is important and is often most easily accessible in recent successfully regenerating harvest areas. Mast, both hard (e.g., acorns) and soft (e.g., crab apples, berries), is important in fall when it is most abundant and provides the opportunity for deer to accumulate fat, especially important in more northern areas. Larger more mature trees and plants produce the most mast. In summer, deer feed on a wider variety of plants including leaves, grasses, and agricultural crops.

Clearly, the home range for deer requires a diversity of plants and stages of development. Deer seem to do best with a diverse selection of plant species upon which to feed and browse. We might liken it to a smorgasbord, where they can pick and choose the plants they need at any given time of the year. If this smorgasbord is poorly stocked, deer may not have the food they need at a given time and struggle to meet their nutritional needs.

Food plots have gained favor among hunters and deer managers as a management strategy for providing nutritional food. However, food plots unless carefully planned and managed may only serve to meet deer needs in spring and summer and artificially increase deer populations. Unless hunting reduces deer populations to match fall and winter habitat conditions, deer will quickly deplete available browse, adversely affecting their habitat.

Therefore, a critical element of deer habitat management is assessing browse conditions year-round. When deer are depending on woody browse and mast, studies have found that they require 4 to 10 pounds of preferred browse each day for every deer using the habitat. That is nearly 1.5 tons of twigs and leaves for each deer each year. In the case where ferns dominate the forest understory, deer may have a difficulty finding sufficient browse to maintain appropriate nutrition, to grow large antlers or to support two fawns from conception to birth. Lacking access to adequate nutrition, they may produce smaller antlers or resorb one or more fetus, thus reducing their ability to sustain the herd. There are techniques for assessing browse quantity and quality; however, a quick assessment should evaluate the relative abundance and diversity of preferred and non-preferred browse plants, the size of twigs browsed, and pronounced evidence of browse lines (DeCalesta and Pierson tally form).

To improve habitat quality, it is important to consider diversity and complexity. If one species becomes too abundant, it may affect other species. In managing habitat, the challenge is to recognize the appropriate mix of species and work to maintain diversity and complexity at appropriate scales. Scale is important. While deer can and do move outside their home range, they do tend to be “home bodies.”

Improving deer habitat quality very often requires a heavy focus on controlling deer numbers and understanding that deer with overlapping home ranges will tend to concentrate in areas with available food and other necessary habitat elements. It is therefore important to think about deer on a landscape level – looking beyond the lands you hunt to the larger context. Necessarily managers have to consider that the deer they wish to manage may easily move to food or cover beyond the lands they manage. In some cases, these lands may not have the same management objectives, and those lands may function as refugia, protecting these deer from culling.

Habitat condition is really the best indicator of a landscape to support deer. When a habitat assessment finds that preferred plants are infrequent and heavily browsed, it is important to reduce deer numbers or increase the amount of browse. There is a paradox in this situation, if conditions are poor and deer numbers are high it easy to understand the need to reduce populations. However, when deer numbers are apparently low and habitat condition is poor, it is difficult to appreciate that further population reduction might be the best management approach. In this situation, even a few deer can over browse the plants in poor habitat.