Thinking outside the black box: Novel approaches to measuring recruitment and source-sink dynamics in migratory species

Ecologists’ understanding of population dynamics has been limited by the challenges of measuring recruitment. For migratory species that disperse and resettle annually, estimating recruitment remains an intractable problem because of our inability to track animals through space and time. In a large-scale study of avian demography, we applied four approaches (e.g., direct transitions, stable isotopes, high-resolution genetic markers, and derived estimates from integrated population models) to measure recruitment and understand its role in source-sink dynamics for a species of conservation concern. Our results discuss scale, resolution, and provide an integrative solution to accurately measure recruitment in migratory animals.