Mapping Migration: Important places for Wyoming's migratory birds

Conservation of migratory birds requires improved understanding of the distribution of and threats to their migratory habitats and pathways. Wind energy development poses a potential threat, which may be reduced if facilities avoid or mitigate impacts in migration concentration areas. However, a current lack of information on the distribution of migratory concentration areas in the western U.S. impedes proactive planning. The Wyoming Natural Diversity Database (WYNDD) and The Nature Conservancy (TNC) developed deductive models of migratory bird concentration areas. Models were based on a synthesis of existing literature and expert knowledge concerning bird migration behavior and ecology, represented through GIS datasets, and validated using expert ratings and known occurrences. Our results were migration maps for four functional groups: raptors, wetland birds, riparian birds, and sparse grassland birds. Key factors included in migration models differed among the four groups, but included streams, topography, wind patterns, wetland size, forage availability, flyway location, proximity to streams, and vegetation type and structure. Experts rated all models as good or very good, and there was significant agreement between species occurrence data and the migration models for all groups except raptors. Our maps provide data to companies and agencies planning Wyoming wind developments. Our approach could be replicated elsewhere to fill critical data gaps and better inform conservation priorities and wind development planning.