The structure of winter bird communities in the northern Negev shrub-steppes: Relating species composition to habitat structure

We describe the structural patterns of granivorous bird communities in a semiarid shrub-steppe during winter and examine whether and how habitat structure and productivity play roles in determining the structure of these bird communities. We used line transects and measurements of microhabitat use to describe the species diversity, species composition, and microhabitat use of the birds in semiarid shrub-steppe habitats across the northern Negev Desert, Israel. We then related those patterns to the structural characteristics of the habitats along the bird transects at two spatial scales. The bird communities in our study were not random samples of the species pool. Bird abundance and species diversity were correlated with the amount and distribution of perennial and annual vegetation; surrogates of seed abundance and habitat structure, respectively. Species assemblies across the landscape were organized in a nested-subsets structure possibly related to habitat structure. Indeed, species composition was rel...