Factors determining species richness patterns of breeding birds along an elevational gradient in the Horn of Africa region

Aim: To document the species richness patterns of breeding birds along elevational gradients and explore its drivers in the Horn of Africa Region. Location: Horn of Africa Region Taxon: Breeding species of birds Methods: Distributional data for breeding birds were collected. Elevational distribution data were extracted, interpolated, and assembled for all birds, passerines and non-passerines. In order to tease apart how different environmental factors contributed to the variation in species richness, we found it necessary to divide the area into four subregions with different climatic regimes and topographic structure. Then, the species richness in each 100 m elevational band was counted along the elevational gradients of each subregion. Pearson’s correlation analyses and ordinary least squares (OLS) regressions were used to examine the relationships between species richness and factors Results: The variation in species richness followed hump-shaped patterns for all subregions, althou...