As wind energy development expands, concern over possible negative impacts of wind farms on birds remains an issue to be addressed. The concerns are twofold: 1) possible litigation over the killing of even one bird if it is protected by the Migratory Bird Treaty Act and/or the Endangered Species Act, and 2) the effect of avian mortality on bird populations. To properly address these concerns, the National Renewable Energy Laboratory (NREL), working collaboratively with stakeholders including utilities, environmental groups, consumer advocates, regulators, government officials, and the wind industry, supports an avian-wind interaction research program. The objectives of the program are to conduct and sponsor scientifically based research that will ultimately lead to the reduction of avian fatality due to wind energy development throughout the United States of America. The approach for this program involves cooperating with the various stakeholders to study the impacts of current wind plants on avian populations, developing approaches to siting wind plants that avoid avian problems in the future, and investigating methods for reducing or eliminating impacts on birds due to the development of wind energy. This paper summarizes the research projects currently supported by NREL.