Abstract
Development of wind-power resources in the western United States is increasing, and additional sites are proposed or under consideration. Considerable avian mortality induced by older wind-energy developments has increased scrutiny and review of proposed projects with respect to impacts on wildlife. Although more recent studies indicated that avian mortality induced by state-of-the-art wind farms was substantially less, their contribution to cumulative impacts to birds may be cause for concern. The United States Fish and Wildlife Service and the wind-power industry nor recommend pre- and post-development monitoring of wind-resource areas to manage impacts to natural resources, especially birds and bats.