Evaluation of methods for estimating population abundance and mapping distribution of wintering scoters and other sea birds

Project Number: 56

Year Funded: 2005

Lead Institution(s): US Fish and Wildlife Service

Project Lead: Mark Koneff

Email:

Collaborator(s): Doug Forsell (USFWS), Scott Boomer (USFWS), Andy Royle (USGS), ACJV, SDJV, USFWS, USGS

Location: Atlantic Flyway

Focal Species: All Sea Ducks, Bufflehead (Bucephala albeola), Barrow’s Goldeneye (Bucephala islandica), Common Goldeneye (Bucephala clangula), Harlequin Duck (Histrionicus histrionicus), Long-tailed Duck (Clangula hyemalis), Common Eider (Somateria mollissima), King Eider (Somateria spectabilis), Spectacled Eider (Somateria fischeri), Steller’s Eider (Polysticta stelleri), Common Merganser (Mergus merganser), Hooded Merganser (Lophodytes cucullatus), Red-breasted Merganser (Mergus serrator), Black Scoter (Melanitta americana), Surf Scoter (Melanitta perspicillata), White-winged Scoter (Melanitta delgandi)

Project Description: Population status, trend, and habitat association information are identified as priority needs for scoters in the SDJV Strategic Plan. Survey design for wintering scoters is challenging because these species have large ranges, are subject to substantial distributional shifts among years and within a season, and occur in aggregations. Techniques and challenges for monitoring scoter populations on the breeding grounds are well established, and the weaknesses of current monitoring protocols are well understood. The efficiency and practicality of statistically-rigorous monitoring strategies for mobile, aggregated wintering scoter populations are less clear. This study evaluated an adaptive 2-phase stratified sampling plan to estimate wintering scoter (and other sea duck) population size and provide information on bird distribution. Experimental survey protocols were applied in near- and offshore waters of the mid-Atlantic Coast from New Jersey to Virginia and included estuarine waters of the Delaware and Chesapeake Bays.