Oak-Prairie Wildlife Management
The border above illustrates 5 basic tools (axe, cow, plow, fire, and gun) used for managing wildlife communities. The key to managing natural resources is to use a holistic approach, where all of these Tools are applied to develop and maintain healthy ecosystems. Single species deserve less attention, while the system in which they thrive requires more. Knowing how that system functions, and applying the techniques with which that system developed (e.g., moderate cattle grazing, prescribed burning, hunting) is imperative for its continued existence.
As discussed in Historical Perspective, changes in land use patterns (such as the suppression of fire) have resulted in brush encroachment in many areas, causing a decrease in plant species diversity. Brush control is often viewed as a tool for livestock management rather than wildlife. But when practiced properly, the management of brush improves the habitat for wildlife as well as for cattle. The idea of brush management is to create a mixture of habitat to provide the most benefit. The patterns in which brush is managed determine the amount of "edge" produced.
Many wildlife species, are considered edge animals. This means that the edge of some woods or brush is their preferred habitat. These areas usually provide the most food as well as being close to escape cover.
Key points in the management of brush for wildlife include:
- Brush control patterns will depend on the terrain.
- Shallow or thinner soils do not respond as well to brush control practices.
- Brush cover must be left along water courses.
- The width of wooded strips left should be wide enough to prevent seeing through them during the winter.
- Natural wildlife travel corridors and high quality food plants should be preserved.
- On flat terrain, alternate strips of cleared and wooded areas produce good results. Establish strips at a 1:1 ratio (300 feet cleared and 300 feet wooded).
- Irregular patterns produce a greater amount of "edge." Small clearings (2-3 acres) randomly scattered are a good alternative to strip clearing.
As Aldo Leopold wrote in his 1933 textbook titled Game Management, "...game can be restored by the creative use of the same tools which have heretofore destroyed it - ax, plow, cow, fire, and gun." Leopold often referred to the "cow" as an effective wildlife management tool. Cattle can be used as a tool to manipulate and enhance wildlife habitat and plant diversity (as bison did). The main role of grazing in a wildlife management program is to reduce the quantity of grass, allowing sunlight to reach the lower growing forbs, which are important wildlife foods. Furthermore, this process creates more structural diversity, which is more conducive to nesting, brood rearing, and hiding.
However, like any tool, grazing can also be misused and cause more damage than good. Overgrazing is 1 of the most common habitat problems in the Oak-Prairies district. Too many cattle on a pasture for too long begin to eat more and more browse once the grass is depleted, thereby competing with deer. Heavily grazed pastures also lack nesting cover for quail, turkey, and songbirds as well as fawning cover for deer. Range improvement can be attained through proper grazing rates and by scheduled rest periods to allow pastures to be free of grazing by domestic livestock. Rotational grazing systems should allow pastures to be rested (deferred) during a specified time of the year. Some examples of grazing options in order of preference are: a short duration or "time control" system; a high intensity - low frequency system (HILF); a 3 pasture-1 herd system, and the 4 pasture-3 herd rotational grazing system. Each requires different degrees of involvement and fencing. Professionals from the Natural Resources Conservation Service (NRCS), Texas Agricultural Extension Service, and/or Texas Parks and Wildlife can discuss the advantages and disadvantages of each system.
Disking is a method of soil disturbance that encourages the growth of forbs (commonly called weeds or wildflowers) and other annual plants. Common seed producing forbs enhanced through disking include croton (doveweed), sunflower, and ragweed. Many forb seeds are present in the soil and only require shallow disking to germinate.
The best method of disking for wildlife is long strips 15 to 30 feet in width. These strips should be adjacent to wooded areas or meander through natural cover. The second year in a disking program a new strip adjacent to the first year's disked area should be selected. Thereafter, the strips should be disked in alternate years. This creates a more diverse plant community by maintaining different stages of regrowth.
The optimum time for disking is October through February. It is important to disk before spring green-up or forb growth may not be promoted.
Fires, natural and man-made, played an integral role in maintaining the post oak savannah and coastal prairie ecosystems. Since the 1850s, man has suppressed fire. Once semi-open post oak savannahs now have thick understories of yaupon, and much of the remaining coastal prairies have been invaded by brush.
A prescribed burn program that is used properly with a grazing deferment program, is an effective tool for managing wildlife habitat. Burning increases plant quantity and quality, and enhances habitat diversity. Many plant species are tolerant of fire. Others require fire for adequate germination. Europeans suppressed fire to prevent damage to wooden structures, farmlands, fences, and grazing lands. That eliminated or reduced the role that fire played in maintaining the ecosystem.
Burned pastures can be grazed immediately to reduce grasses that compete with forbs, then deferred to allow the pasture to rest. Portions of the property should be left in permanently unburned cover to insure that plants intolerant of fire are part of the ecosystem diversity. A burning schedule should be maintained to give priority to burning in the winter and early spring before green-up. Even with the best planning, burning "windows of opportunity" always depend on humidity, wind, and fuel moisture. The inexperienced manager should ask for assistance and/or advice from agencies such as TPW or the NRCS. While instructional materials are available, it is suggested that the novice assist on a burn conducted by an experienced person before attempting the first controlled burn.
Data from 1984-93 revealed that the post oak savannah and coastal prairies have higher concentrations of hunters than any other region of the state, with 1 hunter for every 77 and 83 acres, respectively. This is a symptom of the trend of smaller and smaller land parcels as large ranches are sold off in pieces or divided as they are passed from generation to generation. With such high densities of hunters, harvest management plays a key role in the health of a deer herd. You simply cannot harvest a buck for every 100 acres and expect to have any bucks reach 5 or 6 years of age and their full potential; cooperation among landowners through Wildlife Management Associations is often necessary.
In addition to the need to restrict the buck harvest, many parts of the Oak-Prairie region have deer densities that are too high, and warrant the harvest of some does. Good habitat will only support so many deer, and to have healthy deer it is important that the population be maintained within the carrying capacity of the habitat. Although much of the Oak-Prairie district consists of 1-buck counties, does can be harvest through the Managed Lands Deer Permit Program. This program has an advantage over blanket regulations because it allows doe permits to be issued at the rate needed for a particular ranch.
Because of the wide range of deer densities that occur in the Oak-Prairie region, you should contact your local biologist to receive a harvest recommendation.
Today, it is very important that land managers understand basic ecological principles of plant succession, plant growth, food chains, and water, mineral and soil nutritive cycles as they affect range, wildlife, and grazing management. In addition we should know and recognize the basic needs and preferences of the livestock and wildlife species for which we are trying to manage. It is equally important to manage for a high level of plant succession and quality wildlife habitat using the basic tools of grazing, rest, fire, hunting, animal impact, disturbance, and technology. This not only produces high quality habitat and animals, but also can lead to more stable conditions during stress periods such as droughts and winter.