Cliff Attributes and Bird Communities in Jefferson County, Colorado

Abstract

Abstract Bird communities associated with differing cliff variables in Jefferson County, Colorado, were sampled using point counts. Species-specific density estimates and community diversity values were compared among four cliff types: small cliffs, medium cliffs, large cliffs, and non-cliff sites. A model selection was run to determine if cliff variables were associated with changes in species richness. Cliff variables included cliff height, cliff length, cliff verticality, cliff surface roughness, and distance to the nearest cliff. None of the cliff variables were good predictors of variability in species richness. Although no differences existed for bird community diversity estimates, there were significant differences in densities among cliff types for particular bird species. The rock wren (Salpinctes obsoletus Say), canyon wren (Catherpes mexicanus Swainson), violet-green swallow (Tachycineta thalassina Swainson), and white-throated swift (Aeronautes saxatalis Woodhouse) were detected more frequentl...