Discussion
The results of this study demonstrate that lcWGS data is well-suited for highly accurate population assignment, even with weakly differentiated population structure. In the American Redstart, lcWGS data provided an improvement over previous migratory connectivity studies using genetic and stable isotope data by allowing us to identify five genetically distinct breeding populations and clearly delineate population-specific nonbreeding ranges. Identifying migratory connectivity of genetically distinct populations is an essential step toward full annual cycle conservation aimed at preserving unique genetic variation. To this end, we integrate the migratory connectivity results with analysis of population abundance and trends to demonstrate the conservation implications of the observed population-specific migratory patterns. More broadly, we also show that when using lcWGS data for population assignment it is essential to implement a sampling design that balanceseffective sample size across source populations to avoid assignment bias that arises from variation in sequencing depth and population sample size.