Determination of Seabird Density using Marine Radar

The upper coast of Texas has potential for onshore and offshore wind farm installations. Seabirds are important apex predators of estuarine and nearshore marine ecosystems and may be impacted by electricity-generating wind turbines. The area also is a crossroads for trans-Gulf and circum-Gulf of Mexico migrating land birds. Determination of avian density on land is facilitated by laser rangefinders but these instruments are nearly useless over water because water absorbs, rather than reflects, laser beams. Visual counts are limited to daylight hours but many birds migrate at night. Commercial grade marine radars are capable of detecting birds during diurnal and nocturnal hours. The purposes of this study , funded by the State Energy Conservation Office of Texas, were to: (1) determine the efficacy of marine radar for observing coastal birds, (2) quantify the density of coastal birds along the upper Texas coast, and (3) predict the potential for avian mortality due to the presence of wind turbines.