Ogada D.L., Gadd M.E., Ostfeld R.S., Young T.P., Keesing F.
Ornithology Section, National Museums of Kenya, Nairobi, Kenya; Division of International Conservation, U.S. Fish and Wildlife Service, ARLSQ 730, 4401 N. Fairfax Drive, Arlington, VA 22203, United States; Institute of Ecosystem Studies, Box AB, Millbrook, NY 12545, United States; Department of Plant Sciences, University of California, Davis, CA 95616, United States; Bard College, Box 5000, Annandale, NY 12504, United States
Ogada, D.L., Ornithology Section, National Museums of Kenya, Nairobi, Kenya; Gadd, M.E., Division of International Conservation, U.S. Fish and Wildlife Service, ARLSQ 730, 4401 N. Fairfax Drive, Arlington, VA 22203, United States; Ostfeld, R.S., Institute of Ecosystem Studies, Box AB, Millbrook, NY 12545, United States; Young, T.P., Department of Plant Sciences, University of California, Davis, CA 95616, United States; Keesing, F., Bard College, Box 5000, Annandale, NY 12504, United States
Large native mammals are declining dramatically in abundance across Africa, with strong impacts on both plant and animal community dynamics. However, the net effects of this large-scale loss in megafauna are poorly understood because responses by several ecologically important groups have not been assessed. We used a large-scale, replicated exclusion experiment in Kenya to investigate the impacts of different guilds of native and domestic large herbivores on the diversity and abundance of birds over a 2-year period. The exclusion of large herbivorous native mammals, including zebras (Equus burchelli), giraffes (Giraffa camelopardalis), elephants (Loxodonta africana), and buffalos (Syncerus caffer), increased the diversity of birds by 30%. Most of this effect was attributable to the absence of elephants and giraffes; these megaherbivores reduced both the canopy area of subdominant woody vegetation and the biomass of ground-dwelling arthropods, and both of these factors were good predictors of the diversity of birds. The canopy area of subdominant trees was positively correlated with the diversity of granivorous birds. The biomass of ground-dwelling arthropods was positively correlated with the diversity of insectivorous birds. Our results suggest that most native large herbivores are compatible with an abundant and diverse bird fauna, as are cattle if they are at a relatively low stocking rate. Future research should focus on determining the spatial arrangements and densities of megaherbivores that will optimize both megaherbivore abundance and bird diversity. © 2008 Springer-Verlag.
abundance; arthropod; bird; canopy; cattle; community dynamics; herbivore; livestock; mammal; plant community; savanna; species diversity; analysis of variance; animal; article; biodiversity; bird; ecosystem; feeding behavior; food chain; Kenya; mammal; physiology; population density; regression analysis; Analysis of Variance; Animals; Biodiversity; Birds; Ecosystem; Feeding Behavior; Food Chain; Kenya; Mammals; Population Density; Regression Analysis; Africa; East Africa; Kenya; Sub-Saharan Africa; Animalia; Arthropoda; Aves; Bos; Bubalus; Elephantidae; Equidae; Equus burchellii; Giraffa camelopardalis; Giraffidae; Loxodonta africana; Mammalia; Syncerus caffer