TITLE:
Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park
AUTHORS:
Shem M. Mwasi, Sipke E. Van Wieren, Ignas M. A. Heitkönig, Herbert H. T. Prins
KEYWORDS:
Niche Breadth; Diet Composition; Coexistence; Habitat Use; Overlap; Season; Grazer; Competitive Interactions
JOURNAL NAME:
Open Journal of Ecology,
Vol.3 No.6,
September
25,
2013
ABSTRACT:
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.