Application of spatial models to the stopover ecology of trans-Gulf migrants

Abstract

Studies at migratory stopover sites along the northern coast of the Gulf of Mexico are providing an understanding of how weather, habitat, and energetic factors combine to shape the stopover ecology of trans-Gulf migrants. We are coupling this understanding with analyses of landscape-level patterns of habitat availability by using spatially explicit models to simulate avian movements through stopover habitats. The probability that an individual migrant will complete a migration successfully is determined by the bird's energetic status and flight morphology, and the quality, quantity, and spatial pattern of habitats encountered during migration. The models evaluate habitat patches according to their distance from the coast, isolation from other patches of suitable habitat, and habitat quality. Evaluation procedures have been developed from available data on the arrival condition of migrants, energetic and morphological constraints on movement, and species-specific habitat preferences. Window analysis and individual-based modeling are used to demonstrate how the abundance, quality, and spatial pattern of habitats interact with the arrival energetic state of migrants to determine the suitability of migratory stopover habitats along the northern Gulf coast. Our goal is to understand how landscape-scale patterns of habitat conversion may be affecting populations of trans-Gulf migrants.

Citation

Simons, Theodore R.; Pearson, Scott M.; Moore, Frank R. 2000. Application of spatial models to the stopover ecology of trans-Gulf migrants. Studies in Avian Biology. 20(4): 4-14. (Editor’s Note: The Evaluation of Watershed Ecosystem Responses to Natural, Management, and Other Human Disturbances research work unit,Coweeta Hydrologic Laboratory, provided partial funding for this publication.)