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.