B-61366-03

Using Livestock toManage Wildlife Habitat

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Can livestock be used to manage wildlifehabitat? The answer depends on the live-stock and wildlife species in question. Manywildlife species can benefit when their habi-tat is disturbed by livestock (which causeschanges in vegetation composition andstructure), if properly managed. It is notpossible to optimize wildlife and livestockproduction at the same time. However, man-aging for both livestock and wildlife is agood way to diversify your ranching enter-prise. It requires that managers understandthe habitat and food requirements of boththe wildlife and the livestock.

Uniform grazing as a result of high stockdensity can certainly reduce the quality ofwildlife habitat by decreasing plant diversityand the escape, resting, screening and ther-mal cover wildlife need to survive. However,properly managed livestock grazing canimprove wildlife habitat by increasing plantdiversity. For example, light cattle grazing(less than 35 percent use of primary foragespecies) to moderate grazing (35 to 45 per-cent use of primary forage species) usuallyencourages forb production. Many species ofbirds depend on the large seeds of forbs forfood. White-tailed deer also benefit fromforb production. Livestock grazing is mostlikely to have a positive effect in areas withmore than 20 inches of annual rainfall. Indrier areas properly managed light to mod-erate grazing usually does not damage wild-life habitat, but it is unlikely to improve it.

Two of the most economically importantwildlife species in Texas are white-taileddeer and quail, and both benefit from certaintypes of habitat disturbance. For example,both of these species suffer if their habitatchanges completely to brush or completelyto grass, especially midgrass to tallgrassplants which compete with forbs. In otherwords, some type of management is neces-sary in order to maintain good quality deeror quail habitat. Both species can benefitfrom well-managed livestock grazing.

Even if livestock and wildlife species eatsimilar types of food (grasses, browse andforbs), they compete only if food suppliesare limited. They are more likely to competefor food when there is little plant diversity orwhen there are too many animals, eitherwildlife or livestock.

While cattle grazing creates open spacesfor forb production, cattle may competewith white-tailed deer for these forbs. On anannual basis, cattle consume about 12 per-cent forbs, compared to 36 percent forwhite-tailed deer. In spring, cattle forb con-sumption may increase to 25 percent, com-pared to 52 percent for white-tailed deer. A1,150-pound cow eating 2.6 percent of itsbody weight in forage consumes about 30

How Grazing Affects Habitat

Livestock-Wildlife Competition

Grazing and White-tailed Deer

Robert K. LyonsAssociate Professor and Extension Range Specialist

Byron D. WrightAssistant Professor and Extension Wildlife Specialist

The Texas A&M University System

pounds of dry forage a day. If 25 percent ofthat forage is forbs, it would eat about 7pounds of forbs. In comparison, a 100-pound deer consuming forage at 3.5 percentof its body weight eats about 3.5 pounds ofdry forage, of which about 2 pounds wouldbe forbs. If the cow and deer in this examplewere competing for the same forbs, the cowwould be consuming forbs that would other-wise be available for the deer. This potentialcompetition could be a problem if deer man-agement were the primary objective and ifforage were in limited supply (which is oftenthe case on semi-arid rangelands).

A study in South Texas (in a region with32 to 36 inches of average rainfall) showedthat diet overlap (two animal species eatingthe same plant species) between white-tailed deer and cattle ranged from 2 to 64percent. This overlap increased with droughtand a heavy cattle stocking rate for thatarea (6 acres/animal unit/year). In thisstudy, cattle grazing increased plant diversi-ty when rainfall was average or above aver-age, but had no benefit during drought.

Competition caused by drought or exces-sive grazing can be reduced with a grazingsystem that allows each pasture to rest dur-ing the growing season at least once over aperiod of several years. Still, stocking rate isthe most important factor in using livestockto manage wildlife habitat. Where deer arethe primary concern, stocking rates shouldbe light to moderate to avoid overgrazingduring periods of low forage growth.

Bobwhite quail need a variety of plantsuccessional stages (the progressive replace-ment of one vegetation community byanother) to meet their needs for food, coverand space. The successional stage of a pieceof land is described as its “range condition.”Range condition can be rated as poor, fair,

good or excellent depending on the status ofvegetation relative to its natural potential.The correct range condition for quaildepends on location. In areas with deepsoils, a long growing season, and high annu-al rainfall (more than 30 inches), range con-dition should be fair to good. In areas withpoor soils, a short growing season, and lowand variable rainfall, range condition shouldbe good to excellent. Grazing can be used toachieve the proper range condition for quailhabitat. Where the annual rainfall is lessthan 20 inches, grazing should be light tobenefit quail, especially to preserve ade-quate nesting habitat (Fig. 1). In areas withmore than 40 inches of rainfall and abun-dant grasses and forbs, continuous grazingcan be moderate.

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Figure 1. Basketball-sized grass clumps provideexcellent quail nesting sites.

Grazing and Bobwhite Quail

A variety of grazing systems have beendeveloped to meet specific objectives ofrangeland management. Some of the grazingsystems are:

■ continuous;

■ deferred-rotation;

■ rest-rotation;

■ short-duration;

■ high intensity/low frequency;

■ best-pasture;

■ seasonal-suitability; and

■ the Merrill three-herd/four pasturescheme.

Each grazing system has a different effecton wildlife and habitat, and no single systemcan meet all ecological and financial objec-tives on every type of rangeland. Therefore,grazing systems should be selected accord-ing to local conditions and landowner objec-tives. Specialized grazing systems thatstrategically define recurring periods ofgrazing and rest can be used to improverange condition for quail and other wildlife(Fig. 2).

The combination of rainfall and theamount of brush influences the proper graz-ing intensity for quail. In areas that get 20 to30 inches of rainfall, grazing should be lighton rangelands with 5 percent or less brushcover. In such areas, herbaceous plantsmust provide more of the travel and escapecover that would otherwise be provided bybrush (Fig. 3). However, if brush species arediverse and of mature height, grazing can beincreased to moderate levels. Rangelandsthat receive 30 inches of rainfall or morecan be grazed at moderate levels whenthere is 5 percent or less brush cover.

A ranch in Brooks County (South Texas)has successfully used cattle grazing as atool for quail management, the primarymanagement objective of the ranch. Theranch is mostly tallgrass savannah withmesquite and mixed brush. Fire and grazing(with cows) are used to create openings inthe dense tallgrass for feeding sites and forbproduction. Each year within each pasture, adifferent group of 25- to 30-acre patches areburned in late winter. Cattle graze the pas-tures the following spring and summer, withgrazing concentrated on the burned areas.Cattle are allowed to graze these patches

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Figure 2. Quail need a minimum of 300 nestclumps per acre.

Figure 3. Where brush is sparse, quail mustrely more on herbaceous plants for travel andescape cover.

short, which encourages production of forbseeds for the quail and insects for quailchicks. The ranch has various stages ofregrowth mixed with unburned areas, whichcreates the kind of habitat diversity con-ducive to quail production. Grazing periodswithin a pasture are determined by what isbest for quail. Stocking rate is decreasedduring droughts to maintain adequate foodsources and nesting cover. The ranch hasconsistently produced good calf crops withgood weaning weights, and rarely needssupplemental feed, even in winter or duringdrought.

Where turkey habitat is grazed by live-stock, problems can include trampling ofeggs, increased nest predation, poor choiceof nest sites, and limited food.

Trampling is probably not significantunless stock density exceeds 1 animal unitper acre, which is uncommon on mostrangelands in Texas.

Excessive grazing can make turkey nestsmore vulnerable to predators by reducingcover. Even when some areas are protectedfrom excessive grazing predation can be aproblem, because often the protected areasare small and few and nest predators areattracted to such isolated patches of habitat.

Grazing pressure or intensity appears toinfluence the nest sites turkey hens select.Hens usually choose ungrazed or lightlygrazed areas for nesting. Low-growing,thorny bushes or cactus interwoven withgrasses are especially valuable for nesting(Fig. 4). Herbaceous vegetation can becometoo dense or tall for nesting in areas withmore than 30 inches of annual rainfall, sosome grazing would improve nesting condi-tions in those areas.

Excessive grazing by cattle and goats canaffect the food available for turkeys by grad-ually depleting important browse species,preferred grasses and desirable forbs.Therefore, the amount of herbaceous andwoody plants being used by livestock shouldbe carefully monitored when managing forturkey habitat.

To select the species and class (stocker,cow-calf, etc.) of livestock best suited formanaging wildlife habitat, it is necessary tounderstand the diets of both livestock andthe wildlife species being managed. Whenlivestock have their choice of foods (grass,browse or forbs), cattle will eat mostlygrass, sheep mostly grass with more forbsand browse than cattle, and goats aboutequal amounts of grass and browse (Fig. 5).However, their diets shift somewhat by sea-son, and are very dependent on the plantsavailable. If grass is the vegetation to bemanaged, cattle would be the preferredspecies to use because they eat mostlygrass. In theory, sheep or goats could alsobe used to manage grass, but if the wildlifespecies being managed is white-tailed deeror bobwhite quail there is more apt to becompetition for browse and forbs because

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Figure 4. Grass growing among thorny brush orcactus provides good nesting cover for turkeys.

Selecting the Type of Livestock

Grazing and Rio Grande Turkeys

sheep and goats eat more of these plantsthan cattle (Table 1). Therefore, the effect ofgrazing on browse and forbs would have tobe monitored closely. The example animalweights in Table 1 were selected becausethey are typical for modern, mature femalecattle, sheep and goats.

It could be argued that cattle also eatbrowse and forbs and could also competewith deer. However, cattle will not consumeenough forbs or browse to compete withwildlife unless the habitat lacks grass.

Rainfall patterns can be highly variableacross Texas. For example, West Texasreceives less than average rainfall seven outof ten years. Stocker cattle (steers orheifers) may be more appropriate in somesituations than cow-calf operations becausewith stockers it is easier to implement flexi-ble stocking rates to match variations inrainfall and forage production.

A ranch near Brady, Texas provides anexample of how goats, despite their dietarysimilarity with deer, can sometimes be usedto manage white-tailed deer habitat. Angoramutton goats are used to browse shinoak-dominated portions of the ranch. This goatbrowsing stimulates shinoak regrowth,which is more palatable to deer thanunbrowsed plants. The rancher believes thatthe bigger bucks tend to be harvested fromparts of the ranch that are browsed by goatsfor short, intense periods.

The presence of exotic big game must alsobe considered when determining whatspecies and class of livestock (if any) to usefor managing wildlife habitat. There are nowmany species of exotic big game on Texasrangelands, and they can have the sameeffect as livestock.

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Cattle

Sheep

Goats

Forbs 12%Browse 7%

Grass 81%

Forbs 17%

Browse 22%Grass 61%

Forbs 11%

Browse 44%

Grass 45%

Figure 5. Comparing the average annual diets ofcattle, sheep and goats.

Table 1. Potential competition between livestock and white-tailed deer for browse and forbs.

1 cow can consume as much (weighing browse and forbs as 1,150 lbs.) 1.7 white-tailed deer

9 sheep can consume as much (total weight browse and forbs as 1,150 lbs.) 3.5 white-tailed deer

10 goats can consume as much (total weight browse and forbs as 1,150 lbs.) 4.9 white-tailed deer

Example livestock weights are typical for mod-ern females; average weight of white-taileddeer is 100 pounds.

The Effect of Exotic Big Game

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Aoudad

Axis deer

Blackbuck antelope

Fallow deer

Nilgai antelope

Sika deer

White-tailed deer

Herbaceous-dominated range Browse-dominated range

Forbs 30%

Browse 20%

Grass 50%

Forbs 20%

Browse 50%

Grass 30%

Forbs 25%

Browse 15%Grass 60%

Forbs 20%

Browse 50%

Grass 30%

Forbs 20%

Browse 30%

Grass 50%

Forbs 10%

Browse 40%

Grass 50%

Forbs 20%

Browse 50%

Grass 30%Forbs 15%

Browse 60%

Grass 25%

Forbs 20%

Browse 10%

Grass 70%

Forbs 10%

Browse 30%

Grass 60%

Forbs 20%

Browse 30%

Grass 50%

Forbs 20%

Browse 50%

Grass 30%

Forbs 60%Browse 30%

Grass 10%Forbs 30%

Browse 60%

Grass 10%

Figure 6. Comparing the diets of big game exotic wildlife species and white-tailed deer on herbaceous-and browse-dominated ranges. Exotics decrease grass and/or forb consumption and increase browseconsumption as browse becomes the dominant plant type. White-tailed deer consume the sameamounts of grass in either situation.

Like domestic goats, many exotic speciesare intermediate feeders between cattle(grazers) and white-tailed deer (browsers).They can shift their diets relatively easilyfrom grass to browse or browse to grass(Fig. 6). This flexibility makes them verycompetitive with white-tailed deer for forbsand browse (Table 2). In addition, exoticsmay browse 6 feet high or more, which putsremaining browse out of the reach of white-tailed deer because they can browse only to4 feet. White-tailed deer need grass and forbcover approximately 18 to 24 inches high forfawning areas (Fig.7). If both exotics andlivestock are present, too much grass couldbe removed to maintain healthy habitat forwhite-tailed deer and other wildlife.

Livestock, especially cattle, can be used tomanage the habitat of some wildlife speciesif: 1) the grazing is appropriate for thewildlife species in question; and 2) the graz-ing is appropriate at a given time. The live-stock grazing program should be flexible andit should be coupled with a good range mon-itoring program so that the effect of live-stock on wildlife habitat can be evaluated.

White-tailed deer management■ To protect fawning habitat:

● Graze no more than 25 percent of thecurrent year’s herbaceous growth.

● For excellent fawning habitat, managefor tall grass (18 to 24 inches) in alarge percentage of the managementarea.

■ To provide adequate food sources:

● Do not allow livestock to use morethan 25 percent of the current year’sgrowth.

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Figure 7. Grass and forb cover 18 to 24 inchestall is needed for excellent white-tailed deerfawning areas.

Conclusions

Management Recommendations

Table 2. Potential competition betweenexotic big game and white-tailed deer forbrowse and forbs.

1 aoudad can consume as much(average weight browse and forbs as200 lbs. 1.3 white-tailed deer*

1 axis deer can consume as much(average weight browse and forbs as 160 lbs.) 1.0 white-tailed deer

1 blackbuck antelope can consume as much(average weight browse and forbs as75 lbs.) 0.5 white-tailed deer

1 fallow deer can consume as much(average weight browse and forbs as130 lbs.) 1.0 white-tailed deer

1 nilgai can consume as much(average weight browse and forbs as450 lbs.) 1.5 white-tailed deer

1 sika deer can consume as much(average weight browse and forbs as145 lbs.) 1.0 white-tailed deer

* Average weight of white-tailed deer is 100pounds.

**Calculations do not include the grass com-ponent, which is typically less than 15 percentof white-tailed deer diets.

● Do not allow browsing by livestockand wildlife to result in severe hedg-ing of highly preferred browsespecies, to exceed 50 percent onmoderately preferred species by theend of summer, to exceed 50 percenton low-preference deciduous speciesby late fall, or to exceed 50 percenton live oaks and evergreens by theend of winter.

Bobwhite quail management■ To protect nesting habitat:

● Graze lightly or not at all where thereis 20 inches or less of rainfall annual-ly.

● Moderate grazing or even heavy graz-ing may be acceptable in areas withmore than 40 inches of rainfall annu-ally, depending upon the brushspecies available.

● Manage for a minimum of 300 bas-ketball-sized grass clumps per acre.

● Manage for a minimum grass stubbleheight of 8 inches, preferably 12 to14 inches.

■ To ensure adequate food supplies,restrict heavy grazing that would elimi-nate or greatly reduce forbs or grassseeds.

■ Encourage spot grazing on small patch-es of the habitat.

Turkey management■ To protect nesting habitat:

● Graze lightly or not at all in the drierregions of the state or where rangecondition is fair to poor.

● Preserve low, thorny brush interwov-en with grass.

or

● Create grazing exclosures that are100 to 500 acres in size for every3,000 to 5,000 acres of rangeland.

Graze exclosures every 4 to 5 years indry climates and every 2 to 3 years inwetter climates to prevent nestinghabitat from becoming too dense.

Graze exclosures only in July andAugust.

Leave vegetation 18 to 24 inches tallin exclosures with adequate inter-spaces for travel of poults.

■ Outside of nesting areas, use moderategrazing intensity to promote food pro-duction.

For more information:B-6130, “White-tailed Deer Browse Preferences

for South Texas and the Edwards Plateau,”Texas Cooperative Extension.

L-5400, “Stocking Rate: The Key GrazingManagement Decision,” Texas CooperativeExtension.

L-5196, “Integrating Deer, Quail and TurkeyHabitat,” Texas Cooperative Extension.

L-5024, “Range Condition: Key to SustainedRanch Productivity,” Texas CooperativeExtension.

B-6114 , “Grazing and Browsing: How Plants areAffected.” Texas Cooperative Extension.

“The use and management of browse in theEdwards Plateau of Texas.” Natural ResourcesConservation Service. Temple, TX. http://texnat.tamu.edu/cmplants/UseMgmtBrowseEPTX.pdf

Managing Livestock Stocking Rates onRangeland. Symposium Proceedings, 1993.Department of Rangeland Ecology andManagement, College Station, TX. http://texnat.tamu.edu/symposia/index.htm

Preserving Texas’s Quail Heritage into the 21stCentury. Symposium Proceedings, 1999.Department of Wildlife and Fisheries Sciences,College Station, TX. http://texnat.tamu.edu/symposia/index.htm

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