Diet Composition Of Greater Kudu At Mason Mountain WMA
SHAWN GRAY1, T. WAYNE SCHWERTNER2, AND RANDY SIMPSON1
1-Southwest Texas State University, San Marcos, Texas
2-Texas Parks and Wildlife Department, Mason, Texas
Ranching of exotic big game species is a profitable business in Texas. One exotic that has increased in popularity with hunters is the greater kudu (Tragelaphus strepsiceros). Hunters may pay as much as $5,000 for a trophy kudu (Mungall and Sheffield 1994). Traweek (1995) reported there were 155 Texas counties with confined or free-ranging exotic artiodactyls and perissodactyls. The number of exotic species in Texas has increased from 13 in 1963 to 71 in 1994. Fifty eight percent of all exotic animals in Texas were reported in the Edwards Plateau Ecological Region (Traweek 1995) and the Llano Uplift Natural Region (LBJ School of Public Affairs 1978).
The natural distribution of greater kudu is throughout the savannah regions of southern and eastern Africa, which includes stony and broken ground covered with thorn scrub (Mungall and Sheffield 1994). This distribution is located in the political boundaries of Chad, Sudan, Central African Republic, Ethiopia, Kenya, Tanzania, Angola, Zambia, Namibia, Mozambique, Zimbabwe, and South Africa (Estes 1991). Greater kudu showed strong preference for dense vegetation and hillside at Loskop Dam Nature Reserve in South Africa (Underwood 1978).
The first greater kudu arrived in Texas at the San Antonio Zoo on June 30, 1965 (Mungall and Sheffield 1994). They were kept in quarantine until a series of successful reproductions allowed release of part of the offspring to private ranchers (Mungall and Sheffield 1994).
Although the greater kudu has been stocked on several ranches in southern Texas, basic ecological information for this exotic ungulate is lacking for Texas. Such knowledge is necessary to appropriately manage populations and to assess the potential for competition with native wildlife.
Research suggests greater kudu are primarily browsers that minimally utilize grasses. Wilson (1964) found only eight out of 70 (11.4 %) rumen samples containing grass. This was mainly during the wet season. Owen-Smith and Cooper (1985) reported greater kudu spent 62% of feeding time on browse, 19% on forbs, 12% on fruits and flowers, and 7% on grass on an annual basis.
Literature also suggests white-tailed deer (Odocoileus virginianus) are primarily browsers. Using rumen samples, Henke et al. (1988) recorded that white-tailed deer consumed 91% forbs, 8% browse, and 1% grass in the Edwards Plateau Region during May 21, 1986 and July 22, 1986. In the Cross Timbers Region of Oklahoma and Texas, Gee et al. (1991) documented white-tailed deer rumen samples during August 1985 through May 1987 contained 44% forbs, 41% browse, 13% grass, and 1% other. Therefore, a dietary overlap between greater kudu and white-tailed deer could exist.
To date, no research has been conducted to determine the food habits of greater kudu in Texas or in the United States. The goals of this research project are to determine the seasonal food habits and food preferences of greater kudu in the Llano Uplift Natural Region of Texas.
Currently, there is a captive population of about 30 greater kudu on the area, which are located in two pastures (Turkey and South Voca) interspersed with white-tailed deer, sable antelope (Hippotragus niger), and scimitar-horned oryx (Oryx dammah). These two pastures are high-fenced and have a number of distinct range sites.
Seasonal diet for one year will be determined by identification of plant species in fecal pellets using microhistological techniques established by Sparks and Malechek (1968) and later refined by J. L. Holechek (1982). The collection of freshly deposited fecal samples will be seasonal (May 2001, August 2001, November 2001, and February 2002). Samples will be retrieved as soon as the animals leave the area. Sampling will encompass as many different individuals as possible each season, until a total of 1,000 grams of fecal material has been collected.
Selectivity will be established by comparing the diet of greater kudu to the plants available in the habitat during a given season. Thus, vegetative sampling and analysis will be conducted with the fecal sampling. Transect lines will be established within each range site. Woody plants will be sampled using the line-intercept method (Gates 1949) and herbaceous plants will be sampled using Daubenmire frames (Daubenmire and Daubenmire 1968). Chi-square (Neu et al. 1974) and Manly's alpha selectivity index (Manly 1974) will test for selectivity in the use of plants.
After addressing this problem, this basic ecological information can be used to assess dietary overlap and competition between greater kudu and native ungulates (as well as other exotics), compare greater kudu diets in different habitats within the state and North America, and assist those ranching exotic game in determining the feasibility of maintaining greater kudu on their property.
Currently, all of the fieldwork has been completed. Identification of plant species in the fecal material will tentatively start in March of 2002.
- Daubenmire, R. F., and J. B. Daubenmire. 1968. Forest vegetation of eastern Washington and northern Idaho. Washington Agricultural Experimental Station Technical Bulletin 60.
- Estes, R. D. 1991. The behavior guide to African mammals. The University of California Press, Berkeley, California. 611pp.
- Gates, F. C. 1949. Field manual of plant ecology. MacGraw-Hill Book Company, New York, New York. 137pp.
- Gee, K. L., M. D. Porter, S. Demarais, F. C. Bryant, and G. V. Vreede. 1991. White-tailed deer: their foods and management in the Cross Timbers. The Samuel Roberts Noble Foundation, Inc. 118pp.
- Henke, S. E., S. Demarais, J. A. Pfister. 1988. Digestive capacity and diets of white-tailed deer and exotic ruminants. Journal of Wildlife Management. 52(4):595-598.
- Holechek, J. L. 1982. Sample preparation techniques for microhistological analysis. Journal of Range Management. 35(2):267-268.
- LBJ School of Public Affairs. 1978. Preserving Texas' natural heritage. LBJ School of Public Affairs, Policy Research Project Report, 31. The University of Texas at Austin.
- Manly, B. F. J. 1974. A model for certain types of selection experiments. Biometrics. 80:281-294.
- Mungall, E. C., and W. J. Sheffield. 1994. Exotics on the range, the Texas example. Texas A&M University Press, College Station, Texas. 265pp.
- Neu, C. W., C. R. Byers, and J. M. Peek. 1974. A technique for analysis of utilization-availability data. Journal of Wildlife Management. 38(3):541-545.
- Owen-Smith, N., and S. M. Cooper. 1985. Comparative consumption of vegetation components by kudus, impalas, and goats in relation to their commercial potential as browsers in savanna regions. 81:72-76.
- Sparks, D. R., and J. C. Malechek. 1968. Estimating percentage dry weight in diets using a microscopic technique. Journal of Range Management. 21(1):264-265.
- Traweek, M. S. 1995. Statewide census of exotic big game animals, job no. 21, federal aid project no. W-127-R-3, job performance report. Texas Parks and Wildlife Department, Austin. 53 pp.
- Underwood, R. 1978. Aspects of kudu ecology at Loskop Dam Nature Reserve, Eastern Transvaal. South African Journal of Wildlife Research. 8:43-47.
- Wilson, U. J. 1965. Observations on the greater kudu Tragelaphus strepsiceros Pallas from a tse-tse control hunting scheme in northern Rhodesia. East African Wildlife Journal. 3:27-37.