Comparative Food Habits of Deer and Three Classes of Livestock Author(s): Craig A. McMahan Reviewed work(s): Source: The Journal of Wildlife Management, Vol. 28, No. 4 (Oct., 1964), pp. 798-808 Published by: Allen Press Stable URL: http://www.jstor.org/stable/3798797 . Accessed: 13/07/2012 12:15
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http://www.jstor.org COMPARATIVEFOOD HABITSOF DEERAND THREECLASSES OF LIVESTOCK
CRAIGA. McMAHAN,Texas Parksand Wildlife Department,Hunt
Abstract: To observe forage competition between deer and livestock, the forage selections of a tame deer (Odocoileus virginianus), a goat, a sheep, and a cow were observed under four range conditions, using both stocked and unstocked experimental pastures, on the Kerr Wildlife Management Area in the Edwards Plateau region of Texas in 1959. The animals were trained in 2 months of preliminary testing. The technique employed consisted of recording the number of bites taken of each plant species by each animal during a 45-minute grazing period in each pasture each week for 1 year. Results indicated moderate to heavy competition for browse and mast between the deer and goat in all pastures during all seasons, and between the deer and all three classes of livestock in the winter. Browse and mast comprised over 50 percent of the deer's diet, except in the spring and summer, and over 50 percent of the goat's diet in all seasons. Following a decrease in available browse, sheep become competitive with deer for forbs. Forbs formed an average of 68 percent of the deer's diet and 65 percent of the sheep's diet in the ungrazed control pasture in the summer; the animals generally were grazing the same species. The added factors of bearing and nursing fawns, and growing antlers, contribute to the nutritional stresses on deer in the summer, the period when extensive die-offs of deer most frequently occur in the Edwards Plateau region. Competition for grass between deer and livestock probably is important only when grass is in a succulent stage in the spring and no other forage is available in quantity. Continuous grazing by animals tends to remove the most palatable species and concentrates competition on fewer, less palatable ones. Observationsfrom the numerous replications of feeding times and places allow the conclusion that this technique provides a reliable index to preferred foods and staple foods.
In the Edwards Plateau region of Texas, tivity of deer and livestock in high densities most of the rangelands are grazed by two (Hahn 1945, Taylor and Hahn 1947). Pre- or more classes of livestock along with deer. vious studies of its vegetation in relation Research on the Kerr Wildlife Management to deer and livestock were reported by Area, near Hunt, Texas, indicates that deer Buechner (1944), Taylor and Beuchner when managed and harvested properly can (1943), and Whisenhunt (1949). On the provide economic returns comparable to Kerr Area, particularly the pastures in- those from domestic livestock. But a study volved in this study, the prominent vegetal of the economic feasibility of management expression is a savannah of live oak, in for livestock and deer in combination re- which Ashe juniper (Juniperus ashei) and vealed the need for more exact knowledge shin oak are conspicuous. of their competition for forage. To provide Part of the Kerr Wildlife Management such information, a study of the food habits Area contains 10, 96-acre deer-proof pas- of cattle, sheep, goats, and deer was initi- tures which are used for a long-term study ated in May, 1959, and concluded in May, of the influence of combined sheep, goat, 1960. and cattle grazing rates on deer production. The Kerr Wildlife Management Area is a Each species of animal obviously has a dif- research facility of the Texas Parks and ferent influence on the welfare of the others Wildlife Department located in Kerr and on the forage resource in general, but County in the eastern portion of the Ed- the experimental design had revealed only wards Plateau. This region, encompassing the gross influence of combinations of ani- some 26,000 square miles of central Texas, mals. probably is unique in its combined produc- Performances of deer in experimental pas- 798 FOOD HABITS OF DEER AND LIVESTOCK * McMahan 799
tures (Table 1) indicated clearly that live- Table 1. Average performances of deer maintained in ex- stock had a effect on perimental pastures with and without livestock from 1957 grazing pronounced through 1962. deer production. Only with little or no HERD competition from livestock did deer survive YEARLY LOSSES OF INCRE- and More exact PASTURES AND STARTING ADULTS MENT reproduce satisfactorily. STOCKING RATES* POPULA- (PERCENT) (PER- knowledge of the kinds and quantities of TIONt CENT) forage necessary for successful deer produc- 1 and 4 tion was needed. Heavy use by livestock 6 40 -43 2 and 5 Previous measurements of use on vegeta- Moderate use by tion (May 1959, Vallentine 1959) did not livestock 9 14 9 distinguish the effects of each kind of ani- 3 and 6 use livestock 8 14 6 mal. To obtain this information, we used Light by 7 tame animals whose activities could grazing Deer only, 8.0 acres be observed at close range with accuracy per deer 12 3 42 by what was called the animal bites method. 8 To our this method has been Deer only, 6.4 acres knowledge per deer 15 5 32 used previously only by Wallmo (1951). The author wishes to the * Each pasture contains 96 acres. acknowledge t Summation of all sex and age-classes of deer in technical assistance of T. A. Booker, for- paired pastures. merly with the Texas Parks and Wildlife Department, and the biometrical advice of This provided two groups of domestic Dr. O. C. Wallmo, the Arizona Game and livestock, A and B, with one animal of each Fish Department, and Dr. R. B. Davis, De- species in each group. In the testing sched- partment of Wildlife Management, Texas A. ule, each animal in Group A was grazed and M. University. In addition, gratitude during two different times on 1 day, and is expressed to Dr. Wallmo for his editing the following day Group B was grazed in of the manuscript. This is a contribution the same manner, during the same times of Texas Federal Aid Project W-76-R-4, and under the same conditions as Group Texas Parks and Wildlife Department, and A on the previous day. the U. S. Bureau of Sports Fisheries and In addition to training the animals, the Wildlife, cooperating. preliminary tests were intended to deter- mine: (1) the individual differences in PRELIMINARYTESTS preference for plant species within species Prior to initiating the study, the animals of livestock, (2) the influence of various to be used were trained for 2 months during degrees of supplementary feeding (moder- March and April, 1959. A mature male deer ate, light, or no feed) upon grazing behav- that had been raised as a pet was obtained ior, (3) the influence of time of day on and used because of his availability and forage preferences, (4) the length of graz- familiarity with the vegetative complex on ing period (1 hour, 45 minutes, or 30 the area. Two nanny goats, two ewes, and minutes) most suitable for providing the two cows were borrowed from the grazing desired body of data, and (5) the feasibility lessee on the area. Adult female livestock of using gentle animals in food habits re- were used because they represented the search. kind of animals most common on range- The preliminary tests were conducted on lands. a 22-acre area of uniform topography, soil 800 Journalof Wildlife Management,Vol. 28, No. 4, October 1964
type, and vegetative cover. The deer was correspond with the feeding normally given conditioned to respond to call, to following, range stock in different seasons. and to being led. The animals were trans- Several major conclusions pertinent to ported to and from the grazing area in the conduct of the study were drawn from either an open or closed (with sideboards) the preliminary tests: pickup truck, with a small livestock trailer. (1) Retaining the animals in pens and This mode of transportation did not disturb providing controlled supplementary feed the deer to any observable extent. was preferable to allowing them to graze A separate series of tests was also run in freely in a pasture between observation which the animals were allowed to run free periods. in a 90-acre trap while not being used in (2) Comparison of Groups A and B grazing observations. When a test was de- indicated that the two individuals of each sired, each animal was called to the truck, species among the sheep and goats made transported to the feeding area, and ob- forage choices that were significantly dif- served during either the early morning or ferent in statistical terms. This was not true late evening. Even though these periods of the two cows. The differences found are times of concentrated grazing by range were attributable to the greater docility of livestock and deer, the experimental ani- the animals in Group A which ate more, mals frequently would not graze at all or and more often, than did those in Group B. would not eat enough to provide an ade- In view of this, Group A animals were quate sample of normal activities. finally chosen for the study. Since there Retaining the animals in pens and con- was no opportunity to compare the forage trolling food intake between grazing trials selections between two tame deer, observa- provided better results. In the case of the tions were made on wild deer feeding in the deer, supplementary feed was varied until same area as the tame animal. These com- the animal grazed and behaved most nearly parative observations gave the impression in the manner observed in wild deer. There that the gentle deer's grazing habits were was relatively little difference noted in the not different from those of wild deer. Both deer's grazing behavior from either light or the tame deer and the wild animals ap- no supplementary feeding, and a twice- peared to eat the same browse and weed daily, light supplementary feed was adopted, species. consisting of 11 pounds of whole-grain corn (3) Early morning, 7:00 to 8:00 AM, and and I pound of alfalfa hay. With no supple- late evening, 5:00 to 7:00 PM, seemed the mentary feeding, the livestock grazed in an most desirable grazing periods; during these intent, greedy manner with less selection times all animals behaved and grazed well than was evidenced following light feeding. and their selections included more species The light, twice-daily supplementary feed- of plants. ing rate adopted for each sheep and goat (4) A 45-minute grazing period yielded was 2/2%pounds of 20 percent protein range about the same number of species grazed cubes and 1 pound of prairie or cane hay. as did a 1-hour period, and considerably The cow was fed 5 pounds of 20 percent pro- more than a 30-minute period. tein range cubes and 5 pounds of prairie or Since there seemed to be no great devia- cane hay twice daily. Kinds and amounts of tions between feeding behavior of tame and supplementary feed were varied during the normal animals, the study was deemed actual study with livestock, however, to feasible. FOODHABITS OF DEER AND LIVESTOCK * McMahan 801
METHODS Table 2. The prevailing year-long stocking rates in the three experimental pastures stocked. The animals used and their at the ages ACRES beginning of the study were a white-tailed PAS- PER TURE* RATE ANI- SHEEP GOATS Cows DEER buck deer, 3.5 Hereford cow, 9 MAL years; years; UNITt Rambouillet ewe, 3 years; and Angora nanny, 1 Heavy 8 23 22 3 1 5 years. 2 Moderate 16 10 10 2 5 These animals were grazed in four pas- 3 Light 24 8 7 1 3 tures which the of condi- represented range * Each pasture contains 96 acres. tions existing in the 10 experimental pas- t The components of an animal unit are considered to be five sheep, five goats, or one cow; deer not considered. tures. The prevailing year-long stocking rates are shown in Table 2. All of the four grazing was estimated by the use of 10, 50- test animals were in one of these grazed foot line transects in each pasture, using the 1 and the were pastures day, following day line-intercept method described by Can- taken to another pasture; thus, all of the field (1941). Readings recorded in 40oofoot were covered in a pastures 4-day period and expressed as a percentage of the com- each week in the The year. daily grazing bined 10 lines provided an index to the was 45 minutes animal. Stand- period per difference in forage species availability near the an observer noted the ing animal, within and between grazing treatments. number of bites taken of each and species Following the last grazing observation it to a recorder. Data for each reported each morning, 30-45 minutes were devoted animal were summarized in terms of per- to a visual survey of the phenological con- of total bites of and centage species forage dition of vegetation in the pasture; thus an classes and seasons. In a fac- by pastures account of the vegetal conditions in each torial of variance to these analysis applied pasture was made on each week. the variables were animals, data, pertinent An herbarium with an essentially com- and seasons. We looked for be- pastures, plete collection of the local flora previously tween and within differences in all combi- had been established on the area. Any nations with to of and regard species plants newly occurring plants were collected as classes of taken. forage they were found. The classes of forage considered were: browse (all woody plants, principally trees FINDINGS and shrubs, all mast, and lichens epiphytic the sum of data for the on trees and shrubs); forbs (broad-leafed Considering year, the differences in diets of each of herbaceous plants, including prickly pear species animal were between the stocked (Opuntia spp.)); and grass (plants of the slight 1, 2, and as compared grass and sedge families). pastures (pastures 3) with the differences between the Seasons as defined were spring (March, ungrazed and the stocked pas- April, and May); summer (June, July, and pasture (pasture 9) tures. An of the August); fall (September, October, and example analytical pro- cedure used to elicit diet differences is November); winter (December, January, in Table 3. the February). presented Generally species prominent in the diets in pasture 9 were taken only in trace amounts, commensurate Studies of the Vegetation Accompanying with their availability, in stocked pastures. The abundance of forage available for This was most pronounced during the spring 802 Journalof Wildlife Management,Vol. 28, No. 4, October 1964
Table 3. Class forage percent composition of the total diet.
SEASONS
ANIMALS Spring Summer Fall Winter B* Ft Gt B* Ft Gt B* Ft Gt B* Ft Gt Pasture 1 (Heavy use) Deer 41 44 15 91 4 5 85 2 13 89 5 6 Cow 0 2 98 0 0 100 21 0 79 10 0 90 Sheep 8 27 66 13 4 83 18 1 81 15 1 84 Goat 50 7 43 82 2 16 59 1 40 70 0 30 Pasture 2 (Moderate use) Deer 48 42 11 88 6 6 87 8 6 100 0 0 Cow 1 9 91 0 11 89 17 1 82 8 4 88 Sheep 16 47 37 31 8 61 28 3 68 17 1 82 Goat 62 12 26 88 2 10 76 5 18 87 0 13 Pasture 3 (Light use) Deer 53 35 12 84 7 9 79 10 11 93 2 5 Cow 4 3 93 1 15 84 23 2 75 27 11 62 Sheep 24 38 38 33 7 60 20 3 77 30 2 68 Goat 58 14 28 82 3 16 71 7 22 91 0 9 Pasture 9 (No other use) Deer 37 56 7 32 68 1 57 37 6 89 8 3 Cow 30 22 49 5 10 85 17 10 73 73 15 12 Sheep 27 61 12 14 65 22 28 31 41 51 9 40 Goat 59 36 5 55 38 7 50 41 10 95 2 3
* B-Browse. t F-Forbs. $ G-Grass. and summer months and with such palat- tures. The sheep exhibited significant dif- able species as big bluestem, little bluestem, ferences in forb consumption between all fall witchgrass, knotweed leafflower, arrow- pastures; however, the other two species leaf sida, shin oak, hackberry, and numer- of livestock only exhibited differences be- ous forb species. tween each stocked pasture and pasture 9 In the lumped data for the year, the rela- with regard to forb consumption. In gen- tive consumption of browse and forbs by eral, data within seasons revealed that the the deer was not significantly different outstanding differences in animal diet were between stocked pastures, but there was a between pasture 9 and the stocked pastures. significant difference (at the 0.05 confi- It is apparent from these findings that all dence level) between pasture 9, where more stocking rates in the grazed pastures materi- forbs were taken, and each stocked pasture, ally reduced the availability of preferred where more browse was taken. The per- and some staple foods and modified the centage of grass in the deer's diet was not diets of the experimental animals. Regard- significantly different between any pastures less of stocking rate, only trace amounts of in the year's sum of data. Combining all the most preferred foods (Table 5) remained. seasons, significant differences were noted Under these conditions, as discussed below, in the relative amounts of browse and the result was more direct competition be- grasses consumed by livestock in all pas- tween all species of animals. FOOD HABITS OF DEER AND LIVESTOCK * McMahan 803
Competitionfor Browseand Mast Table 4. Example of analytical procedure used in deter- mining differences in forage utilization between animals in The results indicated moderate to heavy pasture 1 in the summer season.* for browse and mast between competition KEY FORAGE ANIMALS the deer and the in all SPECIES goat pastures during Cow Sheep Goat all seasons. Browse and mast comprised Live oak < xt < x over 50 percent of the deer's diet in all Shin oak seasons and pastures except during the Woollybucket bumelia in 1 41 Greenbrier spring pastures (average percent), Hackberry when succulent grasses were consumed in Ashe juniper x> quantity, and in the summer in pasture 9 Lichen species
Table 5. Preferredforage species withinseasons.
FORAGE SEASONS SPECIEs Spring Summer Fall Winter Live oak (Quercus virginiana) G G DCSG* Live oak mast D DCSG Texas oak (Quercus texana) DC G Texas oak mast DCSG DCSG Shin oak (Quercus breviloba) C Shin oak mast DSG Greenbrier (Smilax bona-nox) DSG DSG Woollybucket bumelia (Bumelia lanuginosa) DCSG DSG SG Hackberry (Celtis texana) DSG DSG DSG Texas winter grass (Stipa leucotricha) C Curly mesquite (Hilaria belangeri) C Little bluestem (Andropogan scoparius) C Big bluestem (Andropogan gerardi) C Fall witchgrass (Leptoloma cognatum) CS Rescue grass (Bromus catharticus) DCSG Ozarkgrass (Limnodea arkansana) D Arrowleaf sida (Sida filicaulis) DSG DSG Knotweed leafflower (Phyllanthus polygonoides) DSG Careless weed (Amaranthus graecizans) DSG Rainlily (Cooperia drummondi) DSG Redseed plantain (Plantago rhodosperma) DSG California filaree (Erodium cicutarium) DS Mat euphorbia (Euphorbia serpens) DSG DSG DSG Wild lettuce (Lactuca serriola) DCG Whorled nodviolet (Hybanthus verticillatus) DSG DSG DSG Dayflower (Commelina spp.) DCSG DCSG Horseweed fleabane (Erigeron canadensis) DSG Velvet bundleflower (Desmanthus velutinus) DCSG Sideoats grama (Bouteloua curtipendula) CS Plains lovegrass (Eragrostis intermedia) DS Pinhole bluestem (Andropogan perforatus) C Southwest carrot (Daucus pusillus) DSG Oxalis (Oxalis dillenii) SG DSG DSG Texas vetch (Vicia texana) CSG
* Animal legend: D-Deer S-Sheep C-Cow G--Goat
flower, redseed plantain, and Texas vetch animals in all pastures and during all sea- were commonly grazed by the cow. sons. Although consumption of grass by Forbs apparently are important to deer the cow in summer and fall was fairly uni- and sheep when available, and direct com- form in all pastures, the species in the diet petition between them probably exists were markedly different in the ungrazed under those conditions. Cattle and goats pasture as distinguished from the three would seem to contribute relatively little stocked pastures. Curly mesquite and to competition with deer for this class of Texas winter grass formed the major items forage. in the grass diet of the cow in all stocked pastures during the spring, summer, and for Grasses Competition fall growing seasons. In pasture 9, she Grass normally was preferred more by consumed large amounts of Texas winter the cow and sheep than by the other two grass only in the spring months (average 21 FOOD HABITS OF DEER AND LIVESTOCK * McMahan 805
percent of the diet). Otherwise, her pref- teau region. While in long-term records, erence was for big bluestem, little bluestem, monthly precipitation means are highest in and fall witchgrass, which, as in the case of summer, the occasional failure of summer preferred forbs, were almost nonexistent rains, accompanied by hot weather and in the stocked pastures. The same general high evaporation losses (Bloodgood et al. feeding pattern was also true for the sheep, 1954), severely inhibits growth of vegeta- except the transposition in pasture 9 was tion. Where livestock grazing has already to fall witchgrass almost exclusively. The depleted the range forage under these con- sheep's use of grass decreased in pasture 9 ditions, game managers in the Edwards during the summer season as the abundance Plateau have learned to anticipate the loss and variety of forbs increased. of deer to starvation. The added factors of Grasses were taken by the deer in very bearing and nursing fawns, and growing small amounts in summer, fall, and winter, antlers, contribute to the nutritional stresses but in appreciable quantities in spring. on deer in this period. Then, abundant use was made primarily of The relative performance of wild deer the succulent growth of rescue grass, and maintained in the experimental pastures on secondarily of Texas winter grass and ozark- the Kerr Area (Table 1) clearly indicates grass. In the spring this forage class com- that excessive forage competition with live- prised 16, 11, and 12 percent of the deer's stock is ultimately detrimental to the wel- diet in pastures 1, 2, and 3, respectively, fare of deer. Under the heavy grazing rate and 6 percent in pasture 9. Presumably, in replicate pastures 1 and 4, the lowest grasses were taken more heavily in stocked reproductive rate occurred (6-year mean pastures because of the lack of sufficient herd increment, minus 43 percent). Deer browse and forbs. in pastures 7 and 8 (no livestock) have con- The greatest use of grass by the goat was sistently maintained healthy productive also during the spring and, as with the deer, deer herds (Table 1). Close attention was where little else was available. In stocked given these deer throughout the study, and pastures, Texas winter grass and rescue no explanation other than nutritional limi- grass were the principal grasses used by tations was found for these increment rates. the goat; in pasture 9 fall witchgrass was Conditions in the various pastures in re- her choice. lation to the observed forage preferences of Competition for grass between deer and deer in pasture 9 seem to provide clues to livestock probably is important only when the problem. In pasture 1, the mean height grass is in a succulent stage and no other of the browse line on the staple browse, live forage is available in quantity. Competition oak, was 57.5 inches. The only browse between sheep and cattle for this class of species that was available in abundance was forage apparently is consequential. Ashe juniper, which, as indicated by pref- erences in pasture 9, is low in palatability late The CriticalSeason to all of the animals tested. Although spring forbs were present in pasture 1 in Special consideration was given to the limited amounts in June, there was very problems of forage conditions and competi- little herbaceous forage thereafter. A heavy tion in the summer season because this is grass cover was evident, but it was com- the period when extensive die-offs of deer posed almost entirely of low palatability most frequently occur in the Edwards Pla- grasses. 806 Journalof Wildlife Management,Vol. 28, No. 4, October 1964
Conditions in pasture 2 were essentially decrease in available browse, sheep become like those in pasture 1, except that slightly the first competitor with deer for weeds more oak browse and forbs were available. when they are available. Judging from the In pasture 3 the gross quantity of available preference by deer and sheep for forb vegetation was notably greater than in pas- species during the summer, it is felt that tures 1 and 2, but the most preferred species competition from sheep is more influential were still scarce. on deer than is competition from cattle or The great contrast was in pasture 9 where goats at that time. This is further substan- there was no browse line, and the variety tiated in the findings by Merrill et al. and quantity of browse and forbs were re- (1957) on the Texas Agricultural Experi- markably greater than in the stocked pas- ment Station, Sub-Station No. 14, Sonora, tures. Although the poorer species made Texas. They reported that deer numbers up a large percentage of the copious grass varied with kinds and intensities of live- cover, the preferred species were present in stock grazing in study pastures that were abundance. Grass conditions in pasture 9 not fenced against deer. Under heavy year- were comparable to those in pastures 7 and long stocking with sheep, goats, or both, 8 where deer grazing alone performed so there was low occupancy by deer. Progres- well. The deer-only pastures did not have sive moderation of the stocking rate, even the luxuriant growth of browse and forbs with sheep and goats present, resulted in found in the control pasture, but they did increased occupancy of the pastures by support most staple species in fair abun- deer. During this period, the drought years dance. of the mid-1950's, all heavy grazing, where The data from this study point to the sheep or goats were involved, effectively paucity of preferred forbs in the stocked deterred deer use. After the drought broke, pastures as a limiting factor in deer per- Merrill et al. (1957) reported that heavy formance during the critical season. It will sheep grazing was accompanied by lowest be noted in Table 4 that as range conditions deer numbers, while heavy goat grazing was improved from pasture 1 to pasture 9, the accompanied by large numbers of deer. mean percentage of grass in all diets de- The inference was that the concentration of creased, and the mean percentage of browse sheep grazing on available forbs will influ- decreased for the goat and deer, while it ence deer more than will the foraging by increased for the sheep and cow, but the goats or cattle. But when there are no mean percentage of forbs increased for all weeds, deer are forced into more direct classes of animals. These data impute a competition with goats. Competition for greater importance to forbs, at least in the grass apparently is of minor importance Edwards Plateau region, than ordinarily ac- except in the relationships between sheep credited them by range managers. and cattle. The paucity of staple and preferred deer DISCUSSION forage in the stocked pastures, as suggested by their preferences in the unstocked pas- Competition ture, is considered to be the factor limiting Considering all seasons, rainfall fluctua- reproduction and survival of the wild deer tion, and plant grazing tolerance, goats maintained in those pastures. It is essential, seem to be the most competitive with deer however, to mention the possible effect on for food, principally browse. Following a deer of artificial confinement with livestock FOOD HABITS OF DEER AND LIVESTOCK * McMahan 807
in small areas. Restricted movement and The behavior of the animals was not con- the inevitable close association with live- stant. Avidity of grazing differed from 1 stock might be stress factors. Also, small day to the next, even though supplemental pastures may result in uniform overgraz- feeding was unchanged. Fluctuations in ing, while in pastures of operational size, total bites taken were particularly evident several hundred or more acres, there exist with the sheep; no conclusive explanation larger remnants of palatable deer forage. was found, although variations in atmo- Under heavy grazing on an operational spheric pressure were thought to be a fac- basis, deer herds ultimately suffer, but their tor. performance is appreciably better than that The animals commonly followed different of the deer in the experimental pastures. grazing routes from the same starting point. These problems are being investigated at Thus the four animals, when grazed on the the present time. same day in the same pasture, actually were sampling from somewhat different Appraisal of Technique vegetation complexes. Direction and veloc- of wind seemed to be the influ- The methods employed did not provide ity major ences on the routes of the deer and an opportunity to learn how closely the diet grazing of an individual animal resembles that of a sheep; they tended to graze into the wind most observations. If a population of like animals. However, the during only slight breeze or no wind was the deer data that were acquired correlated well evident, would in an aimless with the performance of normal animals in graze circling manner. the series of experimental pastures. Although the goat grazed into the wind It was assumed that the experimental most of the time, her grazing route appeared animals were physiologically representative to be influenced by her visual inspection of of the population. As they were apparently the area. Commonly she sought out clumps normal, healthy animals, this may have been of woody vegetation, particularly live oak. a safe assumption except for some limita- The cow was not affected by wind direc- tions. At the end of the first summer the tion, but grazed in an erratic manner which deer became belligerent, so he was castrated indicated searching for desired forage. and his antlers were sawed off to eliminate There was no evidence that the anticipa- the possibility of harm to the observers. tion of supplementary feed after the grazing The cow, ewe, and nanny were bred at the period had psychological effect on grazing but the cow and appropriate times, only activities. Nor was there any apparent dif- ewe all of produced offspring. However, ference in psychological response to dif- the animals remained in health and good ferent pastures. This was suspected once maintained their the weight throughout with the sheep when she declined to graze study. in pasture 1 (heavily stocked). As a check, she was taken immediately to the ungrazed TechnicalProcedures pasture where she still showed no desire to The presence of the observer during the eat. grazing trials occasionally would influence Difficulty in identification of the forage the animals' behavior. All animals except taken was occasionally a problem only with the deer would shy off if approached too grasses in pastures 1, 2, and 3. This was closely. more common in summer when grasses 808 Journal of Wildlife Management, Vol. 28, No. 4, October 1964
were sun-burnt, closely grazed, and lack- in Texas. Texas Agr. Expt. Sta. Bull. 787. ing seed heads. 83pp. Observations from numerous BUECHNER, H. K. 1944. The range vegetation replications of Kerr County, Texas, in relation to livestock of feeding times and places allow the con- and white-tailed deer. Am. Midland Natural- clusion that this technique provides a reli- ist 31(3):697-743. able index to preferred foods and staple CANFIELD, R. H. 1941. Application of the line foods. interception method in sampling range vege- tation. J. Forestry 39(4):388-394. The of identification advantages positive HAHN, H. C., JR. 1945. The white-tailed deer of species and gross estimates of quantities in the Edwards Plateau region of Texas. Texas ingested under conditions and times con- Game, Fish and Oyster Comm. 52pp. Mimeo. trollable by the researcher offset the dis- MAY, M. 1959. A study of the plant composi- of tedium in the tion and utilization by mixed classes of live- advantage technique. stock and white-tailed deer on the Kerr Wild- Monotony was not a limiting factor in ac- life Management Area. Ph.D. Thesis. Texas curately observing the foraging of the deer. Agr. and Mech. Univ., College Station. 131pp. It seemed to act much like wild deer, MERRILL, L. B., J. G. TEER, AND 0. C. WALLMO. with such activities 1957. Reaction of deer populations to graz- intermingling foraging from Texas as and antlers. ing practices. Reprint Agr. Prog- scratching, watching, rubbing ress 3(5):10-12. To an of bites was not keep accurate tally TAYLOR, W. P., AND H. K. BUECHNER. 1943. difficult. Relationship of game and livestock to range Proper gentling, training, and supple- vegetation in Kerr County, Texas. The Cat- tleman 83-86. mentary feeding are essential to effective 29(10):81, of this The deer ---, AND H. C. HAHN, JR. 1947. Die-offs employment technique. among the white-tailed deer in the Edwards used was amenable to such condition- very Plateau of Texas. J. Wildl. Mgmt. 11(4):317- ing. In the numerous repetitions of feeding 323. places in this study, animals developed VALLENTINE, J. F. 1959. Effects of three in- familiarity with the environment and avail- tensities of grazing by domestic livestock and able This that deer under yearlong grazing. Ph.D. Thesis. forage. experience suggests Texas Agr. and Mech. Univ., College Sta- such familiarity is essential to satisfactory tion. 97pp. sampling. Transportation of properly con- WALLMO, O. C. 1951. Range, distribution, and ditioned deer to and from feeding grounds wildlife inventory of species on Fort Hauchuca Area. seem to pose no difficulties. Travel dis- Rept. 3: Fort Hauchuca Wildlife area investigations. Arizona Game and Fish Comm. tances on the area varied from 11/2 to study Completion Rept., Job 3, Project 46-R-1. 2 miles, but the deer used was hauled as far 100pp. as 80 miles in the back of a pickup truck WHISENHUNT, M. H., JR. 1949. The flora of with no disquieting effects. two experimental plots in Mason County, Texas, with special reference to its utilization LITERATURECITED by white-tailed deer. M.S. Thesis. Texas Agr. and Mech. Univ., College Station. 88pp. BLOODGOOD,D. W., R. E. PATTERSON, AND R. L. SMITH, JR. 1954. Water evaporationstudies Received for publication October 5, 1963.