Foraging birds respond to a number of factors in the environment, including prey abundance and distribution, vegetation structure, and the presence of predators. Different vegetation types provide differentially suitable feeding structures and prey resources, as well as nesting habitat and predator assemblages during the breeding season.
Many wildlife species use alder-dominated (Alnus spp.) areas for foraging and or reproduction. Stands dominated by alders may have markedly different understory species and structure than do mixed- and conifer-dominated stands. Little is known about the relative value that deciduous riparian areas have to breeding birds in a conifer-dominated landscape.
During the 2002 breeding season, we conducted point counts and nest searches along streams in the Oregon Coast Range. Specifically, we asked if there were differences in the diversity and relative abundance of bird communities in riparian areas dominated by alders versus those dominated by conifers during the breeding season. In addition, we placed nest boxes in riparian areas to target cavity-nesting species and searched for natural nests. The goal of these first-year data is to provide a baseline of demographic information that can be used to generate and test future hypotheses about the relationships among breeding birds, their arthropod prey, and vegetation types in riparian areas.
For additional information about this research study see
the 2003 CFER
Annual Report. (2.2 MB)
