Migration and Winter in the Annual Cycle of Waterfowl

This chapter introduces the role of migration and winter in shaping the ecology, physiology, and conservation of waterfowl. During the non-breeding period, waterfowl face a suite of energetic and behavioral demands that influence their survival and future reproduction. Migration involves complex strategies tailored to species-specific needs and environmental conditions, with decisions about stopover use, nutrient storage, and timing linked directly to future fitness. Physiological processes such as molt, courtship, and fat accumulation often overlap or occur in rapid succession, requiring precise coordination and access to reliable habitat. These demands highlight the importance of habitat quality across space and time, particularly at staging areas and wintering grounds. This chapter emphasizes the concept of carry-over effects, where conditions during migration and winter influence subsequent survival or breeding performance. Conservation that focuses narrowly on breeding habitats overlooks the influence of the non-breeding season on population dynamics. Technological advances have expanded the ability to monitor movements, energy use, and seasonal connectivity, offering new tools for informed management. As habitat loss, climate change, and land-use conversion reshape migratory landscapes, conservation strategies must reflect a full annual cycle approach to effectively sustain waterfowl populations across North America.