Distribution, abundance, and habitat association of riparian-obligate and -associated birds in the Oregon Coast Range

摘要

The abundance, distribution, and habitat associations of the aquatic-foraging riparian-associated vertebrate community were studied during 1992-94 along four stream basins transecting managed forests in the Oregon Coast Range. Riparian areas were typically forested by Alnus rubra, Pseudotsuga menziesii, Acer macrophyllum and Thuja plicata. The riparian-associated community consisted primarily of birds with few observations of mammals. Belted kingfishers (Ceryle alcyon) [Megaceryle alcyon]. Americandippers (Cinclus mexicanus), great blue herons (Ardea herodias), and mallards (Anas platyrhynchos) comprised >85% of these observations. Bird abundances among years were not different (all P > 0.05). Species distribution was affected by stream order, stream basin, and season in each species, but to varying degrees. Key habitat components that were predictive of use were species specific. Most notably, the presence of a forested riparian area, streamside trees, and valley walls that constrain the streamwere important predictors of use by the three most abundant species: dippers, kingfishers, and great blue herons.