Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-24T16:29:39.043Z Has data issue: false hasContentIssue false

Overlap and seasonal shifts in use of woody plant species amongst a guild of savanna browsers

Published online by Cambridge University Press:  10 March 2011

Christopher A. J. O'Kane*
Affiliation:
Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Zoology Department, University of Oxford, Tubney House, Tubney, Oxon OX13 5QL, UK Institute of Systems Science, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa
Kevin J. Duffy
Affiliation:
Institute of Systems Science, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa
Bruce R. Page
Affiliation:
School of Biological and Conservation Sciences, Westville Campus, University of KwaZulu Natal, Private Bag X 54001, Durban 4000, South Africa
David W. Macdonald
Affiliation:
Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Zoology Department, University of Oxford, Tubney House, Tubney, Oxon OX13 5QL, UK
*
1Corresponding author. Email: [email protected]

Abstract:

To clarify the potential influence of different browsers in the same guild on woody vegetation, dietary overlap and separation between elephant, giraffe, kudu, nyala and impala was assessed in Hluhluwe-iMfolozi Park, South Africa. Woody species browsed, browsing heights, plant-parts browsed and browsing versus grazing were recorded over 2 y by direct observation. We obtained 3068 browse records. Niche breadth (Levins' measure) and overlap (Schoener's index) in species browsed and browsing heights were calculated. Annual and seasonal differences in these measurements, plant-part use and browsing versus grazing were assessed. Elephant utilized the largest number (n = 78) of different woody plant species. Overlap in species browsed was lower between elephant and other browsers than amongst the latter. Seasonal rainfall influenced the range of woody plants utilized, niche breadth in terms of species browsed and browsing versus grazing. Marked resource depletion caused elephant, contrary to theoretical predictions, to narrow niche breadth in terms of species browsed. However, resource depletion rarely had a significant effect on interspecific overlap in species browsed or overlap in browsing heights, on actual browsing heights or plant-parts utilized. A small suite (n = 8) of woody species formed the core diet of all guild members, implying the potential for synergistic impacts by guild members on these species and for competition between populations of different guild members.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

ALBON, S. D., BREWER, M. J., O'BRIEN, S., NOLAN, A. J. & COPE, D. 2007. Quantifying the grazing impacts associated with different herbivores on rangelands. Journal of Applied Ecology 44:11761187.CrossRefGoogle Scholar
BALFOUR, D. A. & HOWISON, O. E. 2001. Spatial and temporal variation in a mesic savanna fire regime: responses to variation in annual rainfall. African Journal of Range and Forage Science 19:4553.CrossRefGoogle Scholar
BEEKMAN, J. H. & PRINS, H. H. T. 1989. Feeding strategies of sedentary large herbivores in East Africa, with emphasis on the African buffalo, Synceros caffer. African Journal of Ecology 27:129147.CrossRefGoogle Scholar
BELL, R. H. V. 1971. A grazing system in the Serengeti. Scientific American 225:8693.CrossRefGoogle Scholar
BOND, W. J. 1993. Keystone species. Pp. 237253 in Schulze, E. D. & Mooney, H. A. (eds.). Biodiversity and ecosystem function. Springer, Berlin.Google Scholar
BOWLAND, J. M. & YEATON, R. I. 1997. Impact of domesticated African elephants Loxodonta africana on Natal bushveld. South African Journal of Wildlife Research 27:3136.Google Scholar
CODRON, D., LEE-THORP, J. A., SPONHEIMER, M. & CODRON, J. 2007. Nutritional content of savanna plant foods: implications for browser/grazer models of ungulate diversification. European Journal of Wildlife Research 53:100111.CrossRefGoogle Scholar
CRAWLEY, M. J. 2002. Statistical computing: an introduction to data analysis using S-PLUS. John Wiley, Chichester. 327 pp.Google Scholar
CUMMING, D. H. M., FENTON, M. B., RAUTENBAUCH, I. L., TAYLOR, R. D., CUMMING, G. S., CUMMING, M. S., DUNLOP, J. M., FORD, A. G., HOVORKA, M. D., JOHNSTON, D. S., KALCOUNIS, M., MAHLANGU, Z. & PORTFORS, V. R. 1997. Elephants, woodlands and biodiversity in southern Africa. South African Journal of Science 93:231236.Google Scholar
DU TOIT, J. T. 1990a. Home range–body mass relations: a field study on African browsing ruminants. Oecologia 85: 301303.CrossRefGoogle Scholar
DU TOIT, J. T. 1990b. Feeding-height stratification among African browsing ruminants. African Journal of Ecology 28:5561.CrossRefGoogle Scholar
EAST, R. 1984. Rainfall, soil nutrient status and biomass of large African savanna mammals. African Journal of Ecology 22:245270.CrossRefGoogle Scholar
FIELD, C. R. & ROSS, I. C. 1975. The savanna ecology of Kidepo Valley National Park. II. Feeding ecology of elephant and giraffe. East African Wildlife Journal 12:115.Google Scholar
FLECKER, A. S. 1997. Habitat modification by tropical fishes: environmental heterogeneity and the variability of interaction strength. Journal of the North American Benthological Society 16:286295.CrossRefGoogle Scholar
GORDON, I. J. & ILLIUS, A. W. 1996. The nutritional ecology of African ruminants: a reinterpretation. Journal of Animal Ecology 65:1828.CrossRefGoogle Scholar
GRAND, T. C. 2002. Alternative forms of competition and predation dramatically affect habitat selection under foraging–predation-risk trade-offs. Behavioural Ecology 13:280290.CrossRefGoogle Scholar
HEROLDOVA, M. 1996. Dietary overlap of three ungulate species in the Palava Biosphere Reserve. Forest Ecology and Management 88:139142.CrossRefGoogle Scholar
HIRST, S. M. 1975. Ungulate-habitat relationships in a South African woodland/savanna ecosystem. Wildlife Monographs 44:160.Google Scholar
HOBBS, N. T., BAKER, D. L., BEAR, G. D. & BOWDEN, D. C. 1996. Ungulate grazing in sagebrush grassland: mechanisms of resource competition. Ecological Applications 6:200217.CrossRefGoogle Scholar
HULME, P. E. 1994. Seedling herbivory in grassland – relative impact of vertebrate and invertebrate herbivores. Journal of Ecology 82:873880.CrossRefGoogle Scholar
HURLBERT, S. H. 1978. The measurement of niche overlap and some relatives. Ecology 59:6777.CrossRefGoogle Scholar
JARMAN, P. J. 1971. Diets of large mammals in the woodlands around Lake Kariba, Rhodesia. Oecologia 8:157178.CrossRefGoogle ScholarPubMed
JARMAN, P. J. 1974. The social organisation of antelope in relation to their ecology. Behaviour 48:215267.CrossRefGoogle Scholar
LAMPREY, H. F. 1963. Ecological separation of the large mammal species in the Tarangire Game Reserve, Tanganyika. East African Wildlife Journal 1:6392.CrossRefGoogle Scholar
LEVINS, R. 1968. Evolution in changing environments: some theoretical explorations. Princeton University Press, Princeton. 120 pp.CrossRefGoogle Scholar
LEWIS, D. M. 1991. Observations of tree growth, woodland structure and elephant damage on Colophospermum mopane in Luangwa Valley, Zambia. African Journal of Ecology 29:207221.CrossRefGoogle Scholar
MADHUSUDAN, M. D. 2004. Recovery of wild large herbivores following livestock decline in a tropical Indian wildlife reserve. Journal of Applied Ecology 41:858869.CrossRefGoogle Scholar
MAKHABU, S. W. 2005. Resource partitioning within a browsing guild in a key habitat, the Chobe Riverfront, Botswana. Journal of Tropical Ecology 21:641649.CrossRefGoogle Scholar
MCDONALD, P., EDWARDS, R. A. & GREENHALGH, J. F. D. 1987. Animal nutrition. Longman Scientific and Technical, Harlow, Essex. 552 pp.Google Scholar
MEISSNER, H. H., PIETERSE, E. & POTGIETER, J. H. J. 1996. Seasonal food selection and intake by male impala Aepyceros melampus in two habitats. South African Journal of Wildlife Research 26:5663.Google Scholar
MOE, S. R., RUTINA, L. P., HYTTEBORN, H. & DU TOIT, J. T. 2009. What controls woodland regeneration after elephants have killed the big trees? Journal of Applied Ecology 46:223230.CrossRefGoogle Scholar
MOSUGELO, D., MOE, S. R., RINGROSE, S. & NELLEMAN, C. 2002. Vegetation changes during a 36-year period in northern Chobe National Park, Botswana. African Journal of Ecology 40:232240.CrossRefGoogle Scholar
MUCINA, L. & RUTHERFORD, M. C. 2006. The vegetation of South Africa, Lesotho and Swaziland. South African National Biodiversity Institute, Pretoria. 807 pp.Google Scholar
NAPIER BAX, P. & SHELDRICK, D. L. W. 1963. Some preliminary observations on the food of elephant in the Tsavo Royal National Park (East) of Kenya. East African Wildlife Journal 1:4053.Google Scholar
OLOFSSON, J., HULME, P. E., OKSANEN, L. & SUOMINEN, O. 2004. Importance of large and small mammalian herbivores for the plant community structure in the forest tundra ecotone. Oikos 106:324334.CrossRefGoogle Scholar
OWEN-SMITH, N. 1988. Megaherbivores: the influence of very large body size on ecology. Cambridge University Press, Cambridge. 300 pp.CrossRefGoogle Scholar
OWEN-SMITH, N. 1993. Woody plants, browsers and tannins in southern African savannas. South African Journal of Science 89:505510.Google Scholar
OWEN-SMITH, N., KERLEY, G. I. H., PAGE, B. R., SLOTOW, R. & VAN AARDE, R. J. 2006. A scientific perspective on the management of elephants in the Kruger National Park and elsewhere. South African Journal of Science 102:389394.Google Scholar
PALO, R. T. 1987. Chemical defense in a woody plant and the role of digestive system of herbivores. Pp. 103–107 in Provenza, F. D., Flinders, J. F. & McArthur, E. D. (eds.). Proceedings. Symposium on plant–herbivore interactions. United States Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station, General Technical Report, INT-222.Google Scholar
PIANKA, E. R. 1972. r and K-selection or b and d selection? American Naturalist 106:581588.CrossRefGoogle Scholar
PIANKA, E. R. 1976. Competition and niche theory. Pp. 114141 in May, R. M. (ed.). Theoretical ecology. principles and applications. Blackwell Scientific Publications, Oxford.Google Scholar
PICKETT, T. A., CADENASSO, M. & BENNING, T. 2003. Biotic and abiotic variability as key determinants of savanna heterogeneity at multiple spatio-temporal scales. Pp. 2240 in du Toit, J. T., Rogers, K. H. & Biggs, H. (eds.). The Kruger experience: ecology and management of savanna heterogeneity. Island Press, Washington, DC.Google Scholar
POOLEY, E. S. 2003. The complete field guide to trees of Natal, Zululand & Transkei. Natal Flora Publications Trust, Durban. 512 pp.Google Scholar
RODGERS, W. A. 1976. Seasonal diet preferences of impala from South East Tanzania. East African Wildlife Journal 14:331333.CrossRefGoogle Scholar
ROWE-ROWE, D. T. 1982. The influence of fire on antelope distribution and abundance in the Natal Drakensberg. South African Journal of Wildlife Research 12:124129.Google Scholar
SCHOENER, T. W. 1974. Resource partitioning in ecological communities. Science 185:2739.CrossRefGoogle ScholarPubMed
SCHOLES, R. J. & MENNELL, K. G. 2008. Elephant management: a scientific assessment for South Africa. Wits University Press, Johannesburg. 645 pp.Google Scholar
SCHOLES, R. J. & WALKER, B. H. 1982. An African savanna. Synthesis of the Nylsvlei study. Cambridge University Press, Cambridge. 318 pp.Google Scholar
SCHOOLEY, R. L. 1994. Annual variation in habitat selection: patterns concealed by pooled data. Journal of Wildlife Management 58:367374.CrossRefGoogle Scholar
VAN HOVEN, W., PRINS, R. A. & LANKHORST, A. 1981. Fermentative digestion in the African elephant. South African Journal of Wildlife Research 11:7886.Google Scholar
VINCENT, J., HITCHINS, P. M., BIGALKE, R. C. & BASS, A. J. 1968. Studies on a population of nyala. Lammergeyer 9:517.Google Scholar
WALKER, B. H. 1985. Structure and function of savannas: an overview. Pp. 8392 in Tothill, J. C. & Mott, J. J. (eds.). Ecology and management of the world's savannas. Australian Academy of Science, Canberra.Google Scholar
WALLACE, R. K. 1981. An assessment of diet-overlap indexes. Transactions of the American Fisheries Society 110:7276.2.0.CO;2>CrossRefGoogle Scholar
WHATELEY, A. & PORTER, R. N. 1983. The woody vegetation communities of the Hluhluwe-Corridor–Umfolozi Game Reserve Complex. Bothalia 14:745758.CrossRefGoogle Scholar
WILLIAMSON, B. R. 1975. The condition and nutrition of elephant in Wankie National Park. Arnoldia 7:120.Google Scholar
WOOLNOUGH, A. P. & DU TOIT, J. T. 2001. Vertical zonation of browse quality in tree canopies exposed to a size-structured guild of African browsing ungulates. Oecologia 129:585590.CrossRefGoogle ScholarPubMed