Avian Mortality at Three Wind Energy Facilities on the Gulf Coast of Texas

Three utility-scale wind energy facilities - Pattern Energy Gulf Wind Project and Iberdrola Renewables Peñascal I and II Wind Projects (Facilities) - were built adjacent to each other along the Lower Gulf Coast of Texas on... [ view full abstract ]

Three utility-scale wind energy facilities - Pattern Energy Gulf Wind Project and Iberdrola Renewables Peñascal I and II Wind Projects (Facilities) - were built adjacent to each other along the Lower Gulf Coast of Texas on the coastal sand plains west of the Laguna Madre. The unique ecology of the Texas Gulf Coast suggested the potential for significant adverse impacts to birds, particularly migrating songbirds, as a result of developing and operating these Facilities. In recognition of these concerns, multiple years of post-construction monitoring were conducted to estimate bird mortality at these facilities. Despite substantial concern that wind energy development along the Gulf Coast of Texas might lead to high levels of avian mortality, estimated total avian and diurnal raptor fatality rates at the Facilities were comparable to fatality estimates at other wind energy facilities in North America. The avian species composition of carcasses reflected the coastal location of these projects, with a larger diversity of aquatic bird species compared to the species composition of carcasses found at upland facilities across North America. Nocturnal migrant bird fatalities tended to be found in higher numbers following precipitation events, particularly in spring; however, no large-scale mortality events were discovered at the Facilities.