PARENT SESSION
Oral Session #79: Conservation Ecology: Biodiversity Case Studies and Models. Presiding: T. Rooney.
Friday, August 10, 2001. 8:00 AM to 12:00 PM. Hall of Ideas J.
Avian responses to natural and anthropogenic habitat changes in the Serengeti ecosystem.
ESTES, ANNA1, ARCESE, PETER2, SINCLAIR, ANTHONY2, 1 2
ABSTRACT- This study assessed bird community composition in four habitat types in the Serengeti ecosystem, acacia savanna, grassland, cropland and rural development, to document changes resulting from increasing levels of human disturbance. Understanding the role that disturbance plays in influencing bird communities will allow land planners and conservationists to decide on appropriate levels of disturbance in buffer areas of national parks, while maintaining target levels of biodiversity. I examined community differences among grassland and savanna habitats within Serengeti National Park, and among native habitats and human-altered habitats outside the park. I characterized bird communities using 100m wide belt transects, and analyzed data using a series of paired t-tests and ANOVAs. Bird species richness did not differ among cropland and savanna habitats, and was lowest in grassland and village habitats. Detection density (a relative measure of density) was also lowest in grassland and village habitats. Two groups of birds (large-bodied ground birds and ground nesters) had higher detection densities in grassland, relative to interior savanna (p<0.0001 for both) but did not show the same pattern between cropland and exterior savanna. These groups also had lower detection densities in cropland relative to grassland (p<0.0001). The tree nester group, however, was more frequently detected in cropland relative to grassland (p<0.0001). The most striking disparity occurred in large-bodied ground birds, which were nearly absent in all habitats outside of the park (p<0.0001).
KEY WORDS: Serengeti National Park, avian communities, habitat change, agriculture