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In recent years, near shore areas of the Atlantic Coast have been recognized in their ability to support significant wind resources. Offshore wind development has become one of the fastest growing energy sectors in the world and the focus of the clean energy movement of the United States. The growth of the wind industry will require the development of new technologies, and the construction of new infrastructures. Along the way will be the establishment of new government policies and guidelines to, among many issues, protect significant biological resources including migratory birds and birds of special conservation concern. Minimizing population exposure to a potential hazard is a critical for reducing negative impacts to bird populations. For wind farms, selecting a location that is away from bird concentration areas can reduce the exposure of populations to direct collision mortality and indirect disturbances that reduce the carrying capacity of their habitats. This study provides a spatially explicit profile of an offshore bird concentration area at Cape Charles, VA that can be used to detail the distribution of expected impacts for this location. The specific objectives of this project were to collect information that 1) details the spatial distribution of birds in relation to height above the water and distance from the shoreline within the proposed construction area, 2) provide a relative estimate of abundance for species detected, and 3) provide a sampling of the diversity of species utilizing the proposed area. Bird surveys were conducted on 75 days between 17 October 2011 and 15 May 2012 to encompass the fall, winter, and spring seasons. All surveys began at sunrise and lasted until 1400 EST. Birds were surveyed using a transect line that was oriented perpendicular to the shoreline and extended outward 5 km. A total of 298,519 bird observations of 110 species were made across the three survey seasons (Appendix 1). The Northern Gannet was the numerically dominant species observed and accounted for 49% of all detections. This species was followed in rank order of abundance by the Red-throated Loon, Laughing Gull, and Surf Scoter (15.7, 5.3, and 3.4 % of all detections, respectively). The remaining observations were divided between 106 additional species that included various waterfowl (ducks and geese), waterbirds (gulls, terns, and skimmers), wading birds (herons, ibis), shorebirds (sandpipers, plovers), raptors, and landbirds. We found that groups of species used the study area differently from one another. Some species were predominantly distributed within 1 km of the shoreline, some species were distributed relatively further away from shore, and other species utilized both near and far shore environments uniformly. Moreover, the overwhelming majority of birds were distributed within 30 m of the water surface and did not appear to shift their relative height use in relation to shoreline proximity.


Abundance/Distribution; Biodiversity/Community Structure; Wildlife and Society




The Center for Conservation Biology Technical Report Series, CCBTR-12-06. College of William and Mary & Virginia Commonwealth University, Williamsburg, VA.