Distribution and Abundance of Waterbirds Near Shore in Southeast Alaska, 1997–2002

Abstract

Abstract The 25,000 km of shoreline in southeast Alaska was surveyed for waterbirds by fixed-wing aircraft in summer and winter during the period 1997 to 2002. A ground/boat survey double sampled 20% of the summer habitat and 5% of the winter habitat to adjust and enhance the air survey. The most abundant species during the summer surveys, with visibility correction factors applied, were gulls (Larus spp.; 306,200, CV = 0.004), scoters (Melanitta spp.; 185,700, CV = 0.004), and Harlequin Duck (Histrionicus histrionicus; 34,640, CV = 0.03). The most abundant species observed during the winter surveys were goldeneyes (Bucephala islandica and B. clangula; 121,920, CV = 0.01), gulls (105,000, CV = 0.01), Mallard (Anas platyrhynchos; 98,090, CV = 0.01), scoters (77,300, CV = 0.01), Harlequin Duck (54,540, CV = 0.02), Bufflehead (Bucephala albeola; 46,840, CV = 0.03), and mergansers (Mergus spp.; 39,940, CV = 0.02). The variance estimates did not include uncertainty about the visibility correction factors. We o...