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    South Texas Habitat Management

    South Texas Wildlife Management


    Historical Perspective

    The native rangelands of south Texas have long been noted for its cattle industry and abundant wildlife, especially the trophy white-tailed deer. South Texas contains some of the states premium deer habitat providing excellent amounts of food and cover. However, the vegetative diversity and wildlife abundance has not always been what you see today. History of the settlement and changes in the natural landscape that took place in the Rio Grande plains can be broken down into three time periods: Spanish exploration from 1600-1700's, Colonization of Texas from 1821-1863, and Cattle Empire from 1860- the early 1900's.

    Spanish Colonization 1600-1700's

    Early Spanish explorers had very diverse descriptions of the region with some claiming poor grazing areas while others reported rich fertile pastureland. These discrepancies were due in part to season of travel, amount of rainfall, and route of travel. Tall grass prairies covered with little bluestem, switchgrass, and other native grasses sprawled across the eastern half of the region by some accounts, while the western portion of south Texas in a much drier climate was described as a short grass prairie. The general consensus among early Spanish explorers was that the south Texas plains were predominately a prairie interspersed with mesquite, prickly pear and other woody vegetation. Much of the dense brush was limited to rivers, creeks, drainages, and in small mottes on the prairie. Natural fires were a frequent occurrence and kept much of the brush from infesting the prairie. South Texas was much less brushy 400 years ago than today.

    Except for a few buffalo, antelope, and deer, there was very little natural grazing pressure during this period. Various observers reported deer in all types of habitat from open prairies, the coastal sand plains with limited brush, into the dense chaparral and trees. In the Teran expedition of 1691, Manzanet observed great numbers of buffalo and deer in a "level region without trees" in northern Medina County. Juan Antonio de la Pena's diary of the Aguayo expedition of 1722 reported from an area near the Medina/Atascosa County line, "During the remainder of the day we passed through a flat country and found a great many deer. We saw around us, almost at the same time, as many as three or four hundred of these animals."

    Colonization of Texas 1821-1863

    The American travelers and explorers during the nineteenth century appeared to show a greater interest in the wildlife of south Texas than the earlier Spanish explorers. Apparently, these travelers were more dependent on the natural resources for survival than the well-financed Spaniards who tended to take livestock with them. During this time there was very little grazing pressure. Wild horses that were left or escaped from Spanish were common which added to the native wildlife. As settlement of south Texas increased, livestock steadily began coming into the region and allowed to range freely. There were no fences at this time and animals were moved when necessary to better forage. Deer were plentiful during this period and used for food and hide. Sanchez reported in 1828 as he approached the Nueces River in southern LaSalle County near the San Antonio-Laredo road, "herds of deer on fertile plains". In western LaSalle County between the Frio and Nueces rivers, Bollaert saw "deer in cords" in 1843. He also saw deer and antelope together as he traveled over "mesquite prairies with brushy spots" through northwestern Frio and southwestern Zavala counties. He reported seeing deer or deer sign in McMullen, LaSalle, Frio and Live Oak counties in thick dense chaparral. In 1844, Kirby-Smith reported in Nueces County "more deer than I supposed existed in America".

    In 1849, Whitigs' hunters brought many deer to his camp located in western Kinney County. He also reported an abundance of fat and tender venison in some of the finest mesquite land he had ever seen between Brackettville and the Nueces River in Uvalde County. In 1853, Bartlett reported deer and antelope in great numbers in Brooks County that was on a rolling prairie without trees. Continuing on toward Kingsville, he reported that his party could see miles and saw "large numbers" of deer and antelope. As he traveled on towards Corpus Christi where "not a bush or tree was to be seen", his party saw thousands of deer and antelope and stated that never before had they seen them in such great numbers. Jack Inglis suggested in "A History of Vegetation in the Rio Grande Plains" that these great numbers might have resulted from the drift of animals before a prairie fire they encountered later on. Historical observations of deer in the thick bottomlands were limited, probably due more to the thick vegetation and lack of visibility instead of the lack of animals.

    The Ranching Empire 1860 - early 1900's

    Early ranchers thought the grass would last forever in Texas. As a result, livestock pressure increased with cattle, sheep and goats, and fencing confined them. Settlement also decreased natural fires. From the late 1860's through the 1890's many south Texas counties had more sheep than cattle. Beginning in 1867, 1/2 million sheep were grazed for 3 decades. In 1880, sheep in south Texas represented 45% of Texas' sheep population. In 1889 in the Rio Grande Plains had the four leading sheep producing counties in the state and 10 of the top 15 were in south Texas. The peak decade was from 1880-1890 at times exceeding 2 million head. Sheep were an important ecological factor in changing the landscape, and literally grazed themselves out of south Texas.

    The main factors for change in vegetation in south Texas included overgrazing by livestock, diminished occurrence of natural fire, relatively poor soil (water penetration, nutritive value, aeration, crusting, etc.), climate and precipitation fluctuations, and plenty of brush for seed stock. In the past these factors caused the few natural grazers to rotate to different grazing areas. This region has an overall poor ability for the land to recover due to climate and soil types. As vegetation changed and brush increased, deer numbers subsequently increased.

    As settlement of south Texas increased, deer harvest increased and quality habitat decreased. Deer that had survived historically in the open rangelands could no longer survive there. They were forced into the thicker areas. Besides food deer were hunted for their hides. Until 1900 market hunting was common throughout southwest and eastern Texas and even as late as 1925. Sale of deer hides was an important item of trade before 1900 and many were professionally killed for hides only. Market hunting occurred in south Texas, but the extent is unknown. The majority of the hunting from the 1890's through the early 1900's hunting was from ranchers with a few outside hunters.

    From 1900 through the 1930's, deer hunting was for meat with little regard for age or sex. During this time there were lots of good bucks, very few hunters, large tracts of land, very little access (no roads), few vehicles, and hunting was hard. Most hunters could trespass for free just by asking. The increase in brush density was considered the worst thing to happen to the range and in the late 1930's intensive brush control began that would impact wildlife in Texas for generations.

    Attitudes changed in the 1940's-1950's when hunters began looking for trophy bucks. Access to hunting areas became easier with more roads and vehicles. The oil industry precipitated this change to a large extent. Brush control types and techniques continued and advanced. Landowners found economic incentives through leasing to begin protecting the deer herd and they began protecting females. The hunting lease system was in total operation by the 1950 and 1960's and accessibility increased, as did more vehicles.

    In the late 1950's, Texas Game and Fish Commission initiated the South Central Game Management Survey and began wildlife inventories and research in south Texas. By the 1950's extensive brush control and eradication was in full operation. By the late 1960's wildlife managers became concerned about the effect of brush control on habitat and wildlife. While deer in south Texas have been plentiful throughout recent history, the numbers of trophy bucks were reportedly decreasing. By the 1970's deer were an economically important commodity and management began in earnest!

    The history of south Texas from early Spanish exploration, through settlement and colonization, into the present shows us that managing the habitat and its resources is the most important and critical aspect of maintaining quality wildlife populations.

    Habitat Management

    The South Texas Plains is rich in species diversity. Native mixed brush plant communities support wildlife populations in tune with the carrying capacity of the land. Alterations to existing habitats impact entire ecosystems and the species they support. How these changes affect ecosystems--whether positively or negatively, is dependant on the techniques chosen and their application.

    Aldo Leopold, the father of modern wildlife management published A Sand County Almanac in 1949. In it he quotes "...game (wildlife) can be restored by the creative use of the same tools which have heretofore destroyed it- axe, cow, plow, fire, and gun." "........Management is their purposeful and continuing alignment."

    Wildlife biologists and landowners alike now implement Leopold's habitat enhancement techniques or management tools to mimic some of the natural processes that occurred prior to European settlement in Texas. The key to managing natural resources is to use a holistic approach, where all techniques are applied to develop and maintain healthy ecosystems. Single species deserve less attention, while the system in which they thrive requires more. Knowing how the system functions and applying the technique is critical for its continued existence.

    The border below illustrates Leopold's five basic tools (axe, cow, plow, fire, gun) used for managing wildlife communities in South Texas. Use of these tools in skillful combination allows enhancement or restoration of habitats and management of key species indigenous to the Brush Country.


    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.

    Grazing Management (Cow)

    Prior to European settlement, bison ranged over most of the Great Plains, including Texas. These great herds were constantly on the move to allow grazed areas to recover. Their hooves churned the soil leaving bare areas for annual forbs (weeds & wildflowers) and grasses to take hold. Forb-eating animals like deer and antelope and weed/seed-eaters like dove and quail were attracted to these areas. Land managers today use domestic livestock as a tool to mimic the bison herds-to manipulate and enhance plant diversity for wildlife.

    The primary role of grazing in a wildlife management program is to reduce the quantity of old-growth grass monocultures, allowing sunlight to reach the lower growing forbs (weeds) which are important wildlife foods. In turn, this process also creates structural diversity for nesting, brood rearing, and escape cover.

    A successful grazing management program includes:

    * Appropriate domestic stocking rates - balancing livestock numbers with available forage.
    * Stocking with the appropriate class of animal - Cattle are primarily grass eaters (grazers) but will consume forbs/browse as grass disappears. Most wildlife species prefer forbs and/or browse (browsers) but cannot switch to grass as their preferred foods disappear. On overstocked ranges cattle and exotic species, therefore, compete directly with native species by removing preferred wildlife foods.
    * Pasture deferment through rotational grazing - Range improvement can be attained through balanced stocking rates and scheduled rest periods throughout the year to allow pasture recovery. Deferred grazing system options vary with degree of involvement and fencing requirements, however, the high intensity - low frequency system (HILF) has proven to be the most versatile on South Texas rangelands. In theory, rotational grazing systems are always preferred over continual grazing systems that do not allow plants critical recovery time.

    Livestock grazing should balance animal numbers with available forage.

    Brush Management (Axe)

    Most wildlife species are selective foragers, preferring to feed on a wide variety of plants rather than a few specific ones. Therefore, habitat improvement recommendations should emphasize the need for an even distribution of food supply from season to season, and the production of a wide variety of choice. Brush management or brush sculpturing allows solid stands of woody vegetation to be interspersed with cleared areas. Cleared strips or blocks produce desirable forb (weed) and browse production, while retaining an adequate mosaic of woody cover for escape, nesting, or protection from the elements. Properly utilized brush management practices can improve the menu of escape cover and food plants for both wildlife and livestock.

    All brush management practices affect native populations in some way. Whether those impacts have a positive or negative affect is dependent on how the practice influences food supply and individual cover needs. When brush management techniques are used, it is important to remember these factors:

    * The method of brush removal used should improve wildlife food supply and habitat -i.e. aeration vs. rootplowing.
    * Plant Diversity and general health and vigor of the range should be increased.
    * Removal of desirable plants species should be minimal.
    * The amount and pattern of brush removal is critical. Extreme care should be taken to insure that too much wildlife cover is not destroyed - for example: drainages or sensitive habitats which support roost sites should always remain intact.
    * Soil disturbance should not be applied to highly erodible sites. Any planned practices should consider topography and soil type.
    * The program should be economically feasible and comply with the overall goals/objectives of the management program.
    * Brush control programs should always consider prior mechanical treatments applied to the site.
    * Brush management programs should plan for periodic maintenance of treated areas. Rarely, do any brush treatments completely eliminate brush, but rather they control it.

    Today's wildlife managers use a combination of mechanical treatments with the ultimate goal of soil disturbance to increase water retention, and to reduce competition from undesirable woody vegetation by returning a plant community to its early successional growth stages. Resulting new growth exhibits increased nutritional levels, increased forage production, and increased forage palatability for most wildlife species. Available mechanical habitat manipulation tools include:

    * Prescribed fire- Fire encourages improved nutrient cycling by fixing nitrogen in the soil from burn debris, thereby having a fertilization effect on the range. Fire encourages suppression of selected woody brush species and encourages the variety of herbaceous (forb or weed) growth depending on the timing and severity of the burn. See also: Prescribed Fire.
    * Mechanical Brush Control-Rollerchopping/Aeration-Shallow soil disturbance (4-6 inches deep) and temporary removal of brush canopy to encourage palatable woody re-growth. Brush removal should be accomplished in strip or mosaic patterns (based on topography) to retain wildlife nesting/escape cover needs.

    Soil Management (Plow)

    Have you ever noticed that the first plants to return in a plowed, scraped, or otherwise disturbed area are weeds? Exposed to air, light, and water, seeds that were lying dormant in the soil begin to germinate following soil disturbance. These young, succulent plants are high in nutrient value and attract a variety of wildlife species. South Texas soils typically are deep, loamy sands conducive to tillage by the farm plow. Topography is generally flat to gently rolling as opposed to the steep, rocky draws and bottoms of the Edwards Plateau where soils are highly erodible. Thus, soil tillage is another useful tool when promoting the growth of desirable wildlife foods.

    * Fallow discing - Shallow soil disturbance on open sites to encourage the growth of herbaceous (weed) growth. This method is cost-efficient and particularly effective for the management of bobwhite quail and other ground nesting birds. The technique is applied through the use of a conventional farm disc disturbing the soil to a depth of 4-6 inches. No reseeding occurs; rather the land is simply left to revegetate on its own using native seed stocks-much like plowing a field following the harvest. Seeded areas can also serve as a seed bank allowing native plants to distribute to other areas. Sunflower, ragweed, and croton are common forbs that respond to disking and are beneficial to wildlife.
    * Establishment of food plots - Disturbed sites can also serve as excellent food plot locations to supplement native diets during the stressful late winter or late summer periods. Food plots are created by plowing an area followed by seeding with either native or introduced forages. Food plots typically serve two distinct purposes: attractant or supplement, as determined by the landowner's ranch objectives. Plots planted, as supplement should provide year-round forage for a variety of wildlife species, therefore mixtures are preferred. Most importantly, plots should be seasonal, accessible, and of appropriate size and shape for the targeted species. Food plots should not be used to increase a wildlife population to a level that cannot be supported by the native habitat.

    Prescribed Burning (Fire)

    prescribed burning in the brush country South Texas habitats evolved through fire. However, fires are not all alike. Prescribed fires are also known as controlled burns because they control some plants and encourage the growth of others. Historically, natural and man-caused fires occurred frequently. Biologists now use fire to manipulate vegetation for the benefit of wildlife. A prescribed burning program, in conjunction with grazing deferment and deer harvest management, is an effective tool for managing wildlife habitat. List below are some general benefits of prescribed burning.

    * Enhances habitat diversity by increasing plant quality/vigor & increases the quantity of wildlife foods (forbs) by suppressing non-native grasses.
    * Increases nutrient cycling by fixing nitrogen in the soil from burn debris, thereby having a fertilization effect on the range.
    * Increases moisture filtration into the soil.
    * Controls invasive vegetation which is not fire tolerant such as juniper in the Edwards Plateau or Lehmann's Lovegrass in South Texas.
    * Opens vegetative overstory to allow light penetration to the soil surface for forb and browse production.

    There is an art and a science to using this powerful tool. Fires can be cool or hot. Depending upon weather conditions and management practices before and after the burn, various plants can be selected for or against. Cool fires seldom harm mature trees while hot fires can top-kill trees. A late winter/early spring (before green-up) burning schedule gives priority to ensure the most productive results for wildlife. Even with the best planning, however, windows of opportunity always depend on humidity, wind, and fuel moisture. Landowners/land managers are encouraged to learn how to use prescribed fire by first assisting on a planned controlled burn before attempting one on their own. They should contact professionals with Texas Parks & Wildlife, Natural Resource Conservation Service, or the Texas A&M Extension Service.

    Population Management / Hunting (Gun)


    Mother Nature provides a surplus of animals to compensate for death losses in a species. In populations where management does not occur, animal numbers will soon build to levels exceeding range carrying capacity resulting in habitat abuse, starvation, and death. A regulated harvest helps assure that there is plenty of food for the number of animals present on the range. Balancing deer numbers with the amount of forage available insures maximum body and antler growth in order for more animals to reach their genetic potential.

    Since we know White-tailed deer prefer forbs and woody browse, biologists use these plants to judge the quality of habitats and to assess range overuse should it be occurring. Forbs are seasonal and fluctuate with rainfall patterns and timing of grazing. Woody browse plants, on the other hand, are deeply-rooted and offer more stability. However, not all browse plants are preferred by deer. Woody plants such as whitebrush, twisted acacia, mesquite, coyotillo, and allthorn goatbush offer limited wildlife food value. Other plants such as Texas kidneywood, spiny hackberry (granjeno), Texas porliera (guayacan), saffron-plum bumelia (coma), prickly pear cactus, sugar hackberry, cedar elm, four-wing saltbush, and southwest bernardia are considered preferred deer foods. In assessing habitats, preferred plants should not display removal of over 50% of their current year's growth. If this is the case or if poor quality plants show heavy use by deer (hedging), range overpopulation is probably occurring! When using hunting as a management tool, biologists also consider the sex ratio of bucks to does, the age of the deer, and the genetics of the herd.

    The management techniques discussed in the habitat management pages do little good when deer numbers exceed the available food supply. For rangelands to respond to these various management practices, deer must be harvested and maintained at or below the carrying capacity of the land. A balanced harvest also emphasizes the harvest of antlerless (female) deer. Natural predators as well as hunters play a role in keep deer populations at or below carrying capacity of the land. For more information on a regulated harvest for South Texas, see Deer Management in the South Texas Plains. For technical assistance regarding deer management, contact your local TPWD Wildlife Biologist.

    #2
    [ATTACH]149350[/ATTACH]

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      #3
      Hey peyton were in Carrizo do you hunt i am a deer guide on La Bandera just thought i might see were you hunted...

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        #4
        Good read Peyton. Thanks for posting.

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