Understanding the Stopover of Migratory Birds: A Scale Dependent Approach

The development of comprehensive conservation strategies and management plans for migratory birds depends on understanding migrant-habitat relations throughout the annual cycle, including the time when migrants stopover en route. Yet, the complexity of migration makes the assessment of habitat requirements and development of a comprehensive conservation strategy a difficult task. We emphasize that development of a comprehensive conservation strategy depends on understanding that migrant-habitat relations during passage are scale dependent, and we outline a practical framework for the study of migrants during stopover that reflects spatial scale and allows us to draw stronger inferences about the behavior, ecology and conservation of migratory birds. This framework is organized into four components, each providing an increasing degree of resolution and information at different ecological scales from gross patterns of habitat availability and use by groups of migrants to finerscale information on habitat suitability and consequences of en-route habitat use for individual birds. Combining information from these components with remote-sensing technology and Geographic Information Systems [GIS] places us in a position to develop conservation initiatives and management plans that are focused explicitly on migration and the stopover biology of migratory birds.