Habitat Management

General Concepts
Deer management is both an art and a science. It is the artful application of wildlife science. There is no magic in deer management. Consistently successful management is the result of careful planning and hard work.

Sound deer management follows an orderly procedure:

1. Goals are clearly defined. Ambiguous or vague goals lead to poor management.
2. Pertinent resources are inventoried as thoroughly as practical while considering food, cover, water, space, diversity, abundance, juxtaposition, and impact on the deer population. Things inventoried generally include an area’s size, vegetation (species composition, plant communities, and successional stages), deer population (density, sex ratio, age structure, and herd health), land use practices, human activity, soils, range sites, livestock, management practices on neighboring land, area’s shape, history of an area (land use, vegetational composition, deer population trends, etc.), roads, fences, topography, water, predators, finances, labor, and equipment.
3. Interrelationships (ecology) of the resources are evaluated to delineate the limiting factor(s) preventing attainment of the goals.
4. Feasibility of the goals is examined and if necessary, goals are modified.
5. The most efficient management procedures are identified to attain the goals.
6. The management procedures are implemented.
7. Resources are monitored to evaluate progress and modify management.

Habitat management is the most important aspect of deer management because deer habitat must exist before deer can live on an area. Habitat is manageable. Each aspect of deer habitat (i.e., food, cover, water, and space) can be improved.

Habitat determines deer carrying capacity. Carrying capacity is the maximum number of deer an area can support without habitat being degraded. Carrying capacity is somewhat difficult to measure because it changes continuously. These changes are caused by changing weather (rainfall, temperature, etc.), soil properties (fertility, erosion, etc.), plant communities, and management. Carrying capacity increases when the limiting aspects of habitat are improved.

Habitat management can be extensive or intensive. Extensive management affects much of an area and commonly involves relatively low labor and/or money inputs per acre treated. Intensive management can affect any percentage of an area but is usually applied to relatively small portions of an area. Intensive management typically involves considerable labor and/or money inputs per acre treated. Modifying existing agricultural land use practices such as grazing, burning, weed control, brush control, forage selection, hay production, crop production, and timber production for the benefit of deer are examples of extensive deer habitat management. Practices such as feeding, developing food plots, establishing woody plantings, constructing water sources, and creating and maintaining clearings are examples of intensive deer habitat management.

Usually, extensive deer habitat management is more important and more efficient for increasing deer carrying capacity than intensive management. A manager who ignores existing land use practices and tries to improve deer habitat only through intensive practices can expect costly and inefficient results. However, there are many situations where intensive habitat management coupled with proper extensive habitat management will efficiently overcome limiting factors.

Diversity is a very important concept in the management of deer food and cover. Many different plant species and combinations (communities) of species are necessary to fulfill the nutritional and cover requirements of deer during all seasons and all weather variations. For quality deer habitat, variety is essential.

A very special type of deer habitat worthy of emphasis is riparian habitat. Natural riparian areas are the intricate combinations of water, soils, organic material, rock (not always present), plants, animals, and climate along streams or natural bodies of water. In general, natural riparian habitats in the bottomlands or floodplains of streams provide the highest quality deer habitats in the Cross Timbers region. Properly managed riparian habitats usually support over twice the deer density as nearby uplands. Natural riparian areas support more deer because they have better plant diversity, better soil moisture, better fertility, and thus more food than the uplands.

Food management
Utilizing food habits information for management purposes falls into two categories–habitat evaluation and habitat modification. The plants available to deer and the foods they selected at the NFWU can be used to compare and evaluate other areas in the Cross Timbers. The availability of all the important food plants identified in this publication is certainly not a requisite for having good deer habitat, but a high degree of similarity is most certainly a reasonable and worthy management goal. Further, in order to have good deer habitat in terms of food, several food items listed for each season should be present to provide forage on a year-round basis. Particular attention should be afforded those species listed for summer and winter since food aspects of habitat may be limited in these seasons due to droughty conditions and cold weather, respectively.

Additionally, the importance of diversity can not be overemphasized. It is much better to have useable amounts of a variety of food items, rather than to have excessive amounts of only a few. Different plants provide different kinds, amounts, and qualities of nutrients. Generally, land managers should not key on an individual plant, but rather on groups of plants when trying to evaluate and/or manage deer habitat.

In many cases, specific management procedures that favor each of the important food plant species have not been scientifically documented, so appropriate management techniques often are not clearly defineable. However, where possible, some management comments for individual plants are included in the "comments" section of Appendix C. In addition, several generalities applicable to management of the food component of deer habitat are described in the rest of this section.

Competition between deer and domestic livestock is often misunderstood and/or overlooked in deer management. The four factors in livestock management that have the largest impact on deer habitat are the kind of livestock selected, stocking rate, type of grazing system, and how the grazing system is implemented. While all kinds of livestock represent some level of dietary competition, some kinds of livestock, because of different dietary preferences, have a greater potential for dietary overlap with deer. While actual preferences of various kinds of livestock can vary depending on plant species present, season, plant management (e.g., burning, fertilization, etc.), and stocking rate of the various competitive animals, some generalities may be stated. For example, goats and sheep generally consume significant amounts of browse and forbs. Both also consume grass in varying amounts depending on availability, palatability, etc. Cattle are considered to be grass eaters, although they readily consume various forbs in young growth stages and often use browse species. Goats and sheep generally have higher dietary overlap with deer than cattle and thus are more competitive with deer for food resources. Therefore, in terms of deer management, deer and cattle are probably a more compatible deer-livestock combination. However, some number of deer can coexist with any kind of livestock when livestock are stocked at rates and managed to minimize overuse of important deer food items.

Competition between livestock and deer is intensified by poor habitat conditions. If food sources are limited, livestock competition further limits an area’s ability to support deer. Under these circumstances, competition between livestock and deer is compounded by the fact that livestock tend to be more flexible in their diets than deer; therefore, livestock can utilize a greater variety of food items. When food sources are limited, livestock are apt to consume most of the available deer foods. The common practice of supplementally feeding livestock allows livestock to be even less discriminating foragers, thereby increasing their competitive advantage over deer.

Proper grazing management can generally help minimize competition between deer and livestock. The keys to minimizing livestock competition with deer are proper livestock stocking rates and proper timing and duration of the grazing period. In conventional continuous grazing systems, stocking rates should not exceed the "moderate" level as defined by Soil Conservation Service (SCS) criteria. Stocking at higher rates increases the likelihood of negatively impacting deer habitat.

Controlled rotational grazing systems have some advantages over continuous grazing systems in that they generally allow for rest periods and provide a number of different pastures in various stages of vegetative development. This can improve habitat diversity. Controlled rotational grazing systems involve moving one or more herds of livestock among several paddocks at appropriate times to avoid overuse of desirable plants, enhance forage quality, and control undesirable plants. Controlled rotational grazing systems at no greater than moderate stocking rates are recommended. Moderate rates for controlled rotational grazing systems may be somewhat heavier than the moderate level for continuous stocking.

Cattle grazing can be used to manage quality, palatability, and availability of deer foods. Deer, as do other browsing and grazing animals, prefer young tender growth stages of plants rather than older, coarser vegetation. Cattle can be used to remove some of the ranker growth to promote more palatable, higher quality regrowth. When cattle grazing is managed in a manner that maintains desirable plant diversity and availability, deer often prefer to forage in areas recently grazed by cattle rather than in ungrazed areas. However, during periods of little or no vegetational growth such as in winter or during droughty summers, vegetation removal by livestock can be detrimental to deer habitat quality and result in increased competition between deer and livestock.

Controlled cattle grazing can also be managed to develop and maintain various successional stages of plant communities. Thus cattle grazing can be used to improve the availability of desirable groups of deer food plants adapted to certain stages of ecological succession. For example, subjecting some small selected sites to heavy cattle grazing pressure during late summer in the Cross Timbers often results in a fall and winter vegetational community dominated by bromes and/or cool season forbs. If cattle are removed after impacting the area, these sites can provide valuable fall and winter feeding areas for deer.

Different land use practices associated with livestock and agriculture can also play important roles in deer management. Changing native rangeland into monoculture pastures of introduced grasses is generally detrimental to deer habitat. Deer do utilize some of the introduced grasses (e.g., tall fescue and weeping love grass), however the lack of diversity, the "weed" spraying, and the higher livestock stocking rates and intensive grazing typical in the management of these pastures eliminates most forbs and browse. In as much as deer in the Cross Timbers depend heavily on forbs and browse, practices which eliminate them are detrimental to deer habitat. If deer management is a goal, full coverage "weed" control is not advisable. If some spraying is unavoidable, it is desirable to leave some untreated strips at least 30 feet wide in a pasture. When a wooded area adjoins an open pasture, it is particularly desirable to leave an untreated strip in the open area adjacent to the woods. The same strips should be protected from herbicides each year. This results in a little less grass production, but it can be an inexpensive way to maintain plant diversity, and hence maintain or improve deer habitat.

Prescribed burning is a tool that often is used to manage deer habitat. Burning at the proper time improves vegetative diversity, stimulates desirable food plants, temporarily improves nutritional quality and palatability of plants, and sometimes improves accessibility of food plants. For deer habitat management, the best time to implement most prescribed burns is usually just prior to spring "green-up." In the Cross Timbers, this is usually mid February to mid March. A burn timed in such a manner will generally result in increased forb diversity and abundance. Various desirable legumes such as smooth seed wild bean, partridge pea, and tick clovers seem to be especially stimulated by late winter or early spring burns.

Generally no more than 50% of deer habitat should be burned during a year. Otherwise, deer food and cover could become limiting while the burned area recovers. Additionally, burning several smaller, well distributed blocks of habitat is preferable to burning one large block. This creates a patchwork effect of burned and unburned areas. A patchwork approach provides a favorable mixing of cover types and foods. Some small portions of a relatively large area should probably be permanently protected from burning to maintain the diversity unburned areas also provide.

Small, scattered, late summer burns also can benefit deer habitat. Burns at this time of year generally encourage more forbs than burns at other times of year. However, the area subjected to late summer burns should be small relative to the size of the entire management area because an area burned in late summer typically provides little cover and browse (excluding acorns) during the following fall and winter. Areas exposed to summer burns should have low erodibility characteristics because such areas typically remain relatively bare for about 6 months, thereby increasing erosion potential.

Another way to improve deer habitat is to restrict livestock use of wooded riparian areas (bottomlands or floodplains adjacent to and including a creek, river, or natural body of water). This generally can be accomplished with fencing. Wooded riparian areas are extremely valuable deer habitat (actually wildlife habitat in general) and are very sensitive to livestock disturbance. If these areas have to be grazed, it is best to manage them separately from adjacent uplands and open bottomlands and to graze them lightly. This minimizes the disturbance and trampling that inevitably results from livestock concentration when these areas are managed in continuous or long duration grazing programs.

Food plots are an alternative and/or complimentary method of managing the food component of deer habitat. The type of food plots addressed here are a form of supplemental feeding with the expressed purpose of artificially increasing the deer carrying capacity (the capacity of an area to support deer) of the land. While food plots do fit into some deer management programs, they are not an efficient management technique for everyone. Food plots can be expensive and undependable. If a food plot program is to increase carrying capacity, it must address the limiting forage needs of deer. If deer foods are limited in both late summer and late winter, then both warm season and cool seasons plots should be established. If a land manager successfully supports more deer with an intensive food plot program (the kind that is required if a noticable increase in carrying capacity is to be achieved), failure to maintain the program will adversly affect the deer herd. Land managers considering food plots should realize that plot distribution and forage selection are important considerations. Several small, well distributed, strategically located plots are generally better that one large plot. Cool season food plot plant materials that work well in various parts of the Cross Timbers are wheat, rye, oats, white clover, arrowleaf clover, and sweet clovers. Warm season food plot plant materials include joint vetch, cowpeas, alyce clover, white clover, and sorghum (shorter grain varieties with compact seed heads).

Direct supplemental feeding for the purpose of increasing the number of deer an area can support is an inefficient management practice for most land managers in the Cross Timbers region. For most land managers, other management practices discussed in this publication provide better returns for investments of time and money.

Supplemental feeding requires continual inputs year after year, including considerable cash outlay. Nevertheless, in some cases where most other appropriate habitat and population management practices have been implemented, supplemental feeding might be more cost effective than acquiring additional land to support more deer. Most land managers in the Cross Timbers are not implementing other management practices to their fullest extent, which is one reason why feeding is generally not efficient management for them.

Theoretically, a feeding program should only need to supplement deer habitat when food is limiting, such as possibly winter and late summer. In reality however, a supplemental feeding program probably should feed deer year-round to keep deer acclimated to feeders so most deer will use feed when they need it. Some land managers that successfully use supplemental feeding find it can take 2-3 years of continuous feeding to get the majority of a deer population acclimated to feeders. To lower the risk of disease transmission, feeding sites should be moved a short distance every 2 years.

Finally, regulating deer numbers is one of the most effective techniques for managing the food component of deer habitat. While "Population Management" is discussed in a later section of this publication, it is mentioned here to point out that excessive deer numbers negatively impact deer foods. As is the case with most large herbivores, deer can degrade their own habitat by altering plant communities. Properly managing deer numbers using harvest or other forms of removal can improve the quality and abundance of deer food items.

Cover Management
When lack of cover limits deer habitat, there are two options for improving it: let it reestablish naturally or plant it. Herbaceous cover, such as fawn hiding cover, can usually be improved in one growing season by reducing mowing or grazing pressure. Increasing woody cover generally requires several years.

If an area had woody vegetation historically but is currently lacking it, woody regrowth is most likely prevented by something, such as heavy grazing pressure, a brush control program, tillage, mowing, broadleaf herbicides, or burning. Simply reducing the impacts of these practices should allow existing seeds and rootstocks to reestablish woody vegetation. Relative to brush control, it is important to consider that it is much easier to remove less woody vegetation initially, and more later if necessary, than it is to replace it after it has been removed.

If an area never had much woody vegetation, planting it is probably the most efficient alternative to increase it. Ideally it is best to plant woody species that provide both cover and food such as box elder, dogwoods, osage orange, plums, oaks, sumacs, coralberry, grapes, and possibly winged elm. It is not advisable to plant honey locust or poison ivy due to problems they cause. If an area is suitable for these two species, they will probably show up anyway. After a woody planting becomes successful, birds will eventually help establish greenbriers.

Practicality of woody plantings for deer habitat should be carefully evaluated. Woody plantings are expensive to plant and maintain. The primary cost of a properly-managed, nonirrigated woody planting involves controlling herbaceous competition with weed barrier fabric or frequent mowing, cultivation, and/or herbicide applications. During the first 5 years, often longer, young woody plants should be protected from mowing, broadleaf herbicides, burning, and heavy livestock grazing pressure. Initially, the plantings may also need protection from deer when deer are relatively abundant or when preferred forages are relatively scarce. If a relatively large area has no woody cover, planting at least 15% of it will require considerable labor and materials. Generally, a woody planting requires 5-10 years before it contributes significantly to deer cover.

Although lack of cover more often limits deer habitat than excessive cover, some areas can have too much cover. Fortunately, excess cover can be removed in a relatively short period of time. When excess herbaceous cover limits habitat, controlled grazing or burning are generally the most efficient options to improve the situation. When excess woody cover limits habitat, a mosaic of openings can be created with burning, timber harvest or removal, mechanical brush control, or woody herbicides. Either burning, controlled grazing, herbicides, mowing, tillage, or some combination thereof can be used to maintain the openness of cleared areas.

Water Management
An area where water is limiting can be improved by simply providing a couple of well-dispersed water sources per section (640 acres). Ponds, water troughs utilizing piped water, or wildlife guzzlers can be constructed to provide deer water. A wildlife guzzler collects rainwater on sloping panels that direct the water to a shaded storage tank where it is made available to wildlife.

Space Management
A relatively small area with apparently suitable deer food and cover might not have deer if it is isolated from other deer habitat by considerable distance. Strips of woody vegetation wide enough to conceal deer during all seasons could be planted or encouraged to develop naturally along riparian areas or through a system of windbreak-like plantings. When these strips connect the small patch of habitat to several larger patches with deer, they will provide travel corridors as well as additional areas of deer habitat. This should help a small patch become deer habitat.

Some land managers erect deer fences to better control a deer herd. The minimum acreages or the minimum number of deer that should be enclosed with such a fence has not been thoroughly studied. However, the authors believe the minimum area required to enclose a self-sustaining wild deer population probably should support at least 100 deer while maintaining good fawn crops, good body weights, and good antler characteristics. Population stability requires some minimum quantity of deer (possibly at least 100) to avoid being overly sensitive to changes affecting the population. Possibly only 1,000 acres of land with mostly high quality riparian habitats might satisfy these requirements, while an area with mostly uplands probably requires at least 2,000-3,000 acres. With abundant woody cover and a very intensive and expensive supplemental feeding program, the size of such an area might be reduced to only a few hundred acres.

Without a deer fence, a deer population can use all available habitat in the vicinity. A manager without a deer fence does not need to control enough habitat to support some minimum quantity of deer. Relatively small acreages can have deer as long as neighboring lands help provide adequate deer habitat.

Although small acreages can have deer, improvements in deer population parameters and herd health are very difficult to accomplish when a manager does not control enough land to support a substantial deer population (probably at least 100 deer) . On small places with free-ranging deer, population management is usually ineffective because attempted population changes are quickly diluted by deer movement across property boundaries. However, a manager with a relatively small acreage can participate in a cooperative management program with neighbors to improve deer population parameters, herd health, and habitat on a more extensive scale. A cooperative management program among neighbors can result in a large enough management unit to influence significant changes in an overall deer population.