Birds, Alaska 

The Breeding Bird Survey (BBS) is the most widespread program used to monitor population of landbirds on the North American continent. Each BBS route, which is surveyed once a year, consists of 50 stops placed at 0.8-km (0.5-mi) intervals along a stretch of road. In recent years, the program in Alaska has greatly expanded; observers record more than 200 species on 75 BBS routes and, in a typical year, count about 35,000 individual birds. Although the BBS effectively tracks many bird populations on regional and continental scales, it does not record temporal changes in habitat that could account for bird population fluctuations. Therefore, we undertook a project to assess vegetation covertypes along roadside routes throughout Alaska. Our purposes were to determine bird-vegetation associations and classify vegetation covertypes to monitor future changes. A well-established classification scheme was used to assess vegetation covertypes along 62 roadside BBS routes in Alaska. We used bird count data from the BBS to determine the frequency of occurrence (percent of stops) of 48 landbird species (grouse, hummingbirds, woodpeckers, and passerines) in dominant vegetation types. We
also calculated the average bird density (birds per stop) for three major cover classes (less than 30%, 30-60%, greater than 60%) of forest, shrub, or herbaceous vegetation covertypes. Data are depicted graphically to examine relationships between vegetation covertypes and bird density or occurrence within four biogeographic regions of the state. Abundance and occurrence information for each species in each biogeographic region are also presented. This information illustrates broad-scale bird-habitat associations and will serve as a foundation to compare future changes in Alaska's landscape.