Estuarine habitat utilization by birds in Yaquina Estuary, Oregon

• Main Authors: JANET LAMBERSON, WALTER NELSON
• Format: Text
• Language: unknown
• Published: 2008
• Subjects: Pacific; Branta bernicla
• Online Access: http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=188512

A wide variety of bird species are highly dependent on intertidal wetland habitats. Because of this dependency, birds are viewed as important indicators of wetland structure and function. Wetlands in Yaquina Bay along with the tidal wetlands in other Pacific coastal estuaries regularly support large numbers of migratory shorebirds and waterfowl (swans, geese, ducks). Both groups of birds forage in various habitats within the tidal wetlands complex of the bay, for example Black Brant (Branta bernicla nigricans) and other waterfowl feed on seagrass, and their use of areas of different regions of an estuary appears related to the extent of eelgrass. Based on the importance of wetland habitats to birds, indicators for evaluating habitat level ecosystem include censusing all birds utilizing various intertidal habitats in three sectors of Yaquina Bay at four tide levels, in eight count cycles per year. Habitats to be assessed include intertidal seagrass habitats (Zostera marina and Z. japonica), unvegetated mudflat and sandflat (typically characterized by burrowing shrimp Upogebia and Neotrypaea) and low emergent marsh. Preliminary observations indicate that birds characteristically use these areas differently at different tide levels, for exam