Many small Parks inKenyaare being fenced to control human-wildlife conflict. Some of these Parks have a diversity of large herbivores which might increase in density in the wake of fencing and subsequent compression of their home ranges due to closure of their migratory routes. It is important to understand the consequences of such an increase on the structuring of insularised herbivore assemblages in such Parks. We studied seasonal resource segregation and niche breadth variation as mechanisms of coexistence in a high density grazer assemblage inLakeNakuruNational Parkwhich is small and completely fenced. Diet composition and habitat use were considered as variables of resource use. We predicted that overlap in resource use and niche breadth would be the smallest among grazers with similar body weights in the dry season which is the most resource limiting for grazers in East Africa. Our results were contrary to the predictions because of lack of seasonal differentiation in the overlap of diet composition and habitat use, and in niche breadth. Overlaps in resource use were consistently high during both the wet and dry seasons, and niche breadth contraction during the dry season was not possible probably because of lack of species-specific niches during the dry season. Our results suggest that there might be competitive interactions in this grazer assemblage which is an important parameter to consider in the management of the Park.
 Bell, R.H.V. (1971) A grazing ecosystem in the Serengeti. Scientific American, 225, 86-93. http://dx.doi.org/10.1038/scientificamerican0771-86
 Prins, H.H.T. and Olff, H. (1998) Species richness of African grazer assemblages: Towards a functional explanation. In: Newbery, D.M., Prins, H.H.T. and Brown, N.D., Eds., Dynamics of Tropical Communities, Blackwell Science, Oxford, 449-490.
 Schuette, J.R., Leslie Jr., D.M., Lochmiller, R.L. and Jenks, J.A. (1998) Diets of hartebeest and roan antelope in Burkina Faso: Support of the long-faced hypothesis. Journal of Mammology, 79, 426-436. http://dx.doi.org/10.2307/1382973
 De Boer, W.F. and Prins, H.H.T. (1990) Large grazers that strive mightily but eat and drink as friends. Oecologia, 82, 264-274. http://dx.doi.org/10.1007/BF00323544
 Fritz, H., De Garine-Wichatitsky, M. and Letessier, G. (1996) Habitat use by sympatric wild and domestic grazers in an African savanna woodland: the influence of cattle spatial behaviour. Journal of Applied Ecology, 33, 589-598. http://dx.doi.org/10.2307/2404987
 Sinclair, A.R.E. (1975) The resource limitation of tropic levels on tropical grassland ecosystems. Journal of Animal Ecology, 44, 497-520. http://dx.doi.org/10.2307/3608
 Wrench, J.M., Meissner H.H. and Grant, C.C. (1997) Assessing diet quality of African ungulates from faecal analyses: The effect of forage quality, intake and grazer species. Koedoe, 40, 125-137. http://dx.doi.org/10.4102/koedoe.v40i1.268
 Gordon, I.J. and Illius, A.W. (1989) Resource partitioning by ungulates on the Isle of Rhum. Oecologia, 79, 383-389. http://dx.doi.org/10.1007/BF00384318
 Begon, M., Mortimer, M. and Thompson, D.J. (1996) Population ecology: A unified study of animals and plants. Blackwell Science, Oxford. http://dx.doi.org/10.1002/9781444313765
 Mishra, C., Van Wieren, S.E., Pieter, K., Heitknig, I.M.A. and Prins, H.H.T. (2004) Competition between domestic livestock and wild bharal Pseudois nayaur in the Indian trans-Himalaya. Journal of Animal Ecology, 73, 344-354.
 Prins, H.H.T., De Boer, W.F., Van Oeveren, H., Correia, A., Mafuca, J. and Olff, H. (2006) Coexistence and niche segregation of three small bovid species in southern Mozambique. African Journal of Ecology, 44,186-198. http://dx.doi.org/10.1111/j.1365-2028.2006.00619.x
 Azevedo, F.C.C., Lester, V., Gorsuch, W., Larivière, S., Wirsing, A.J. and Murray, D.L. (2006) Dietary breadth and overlap among five sympatric prairie carnivores. Journal of Zoology, 269, 127-135. http://dx.doi.org/10.1111/j.1469-7998.2006.00075.x
 Ahrestani, F.S., Heitkonig, I.M.A. and Prins, H.H.T (2012) Diet and habitat-niche relationships within an assemblage of large herbivores in a seasonal tropical forest. Journal of Tropical Ecology, 28, 385-394. http://dx.doi.org/10.1017/S0266467412000302
 Mutangah, J.G. (1994) The vegetation of Lake Nakuru National Park, Kenya: A synopsis of the vegetation types with annotated species list. Journal of East African Natural History, 83, 71-96. http://dx.doi.org/10.2982/0012-8317(1994)83[71:TVOLNN]2.0.CO;2
 De Jong, C.B., Gill, R.M.E., Van Wieren, S.E. and Burlton, F.W.E. (1995) Diet selection by roe deer (Capreolus capreolus L.) in Kielder forest in relation to plant cover. Forest Ecology Management, 79, 91-97. http://dx.doi.org/10.1016/0378-1127(95)03622-9
 Pianka, E.R. (1973) The structure of lizard communities. Annual Review of Ecology and Systematics, 4, 53-77. http://dx.doi.org/10.1146/annurev.es.04.110173.000413
 Mwangi, E.M. and Western, D. (1998) Habitat selection by large herbivores in Lake Nakuru National Park, Kenya. Biodiversity and Conservation, 7, 1-8. http://dx.doi.org/10.1023/A:1008891027230
 MacArthur, R.H. and Levins, R. (1967) The limiting similarity, convergence and divergence of coexisting species. American Naturalist, 101, 377-385. http://dx.doi.org/10.1086/282505
 Putman, R.J. (1996) Competition and resource partitioning in temperate ungulate assemblies. Chapman and Hall, London. http://dx.doi.org/10.1007/978-94-009-1517-6