Data from: Mapping migration in a songbird using high-resolution genetic markers

Neotropical migratory birds are declining across the Western Hemisphere,
but conservation efforts have been hampered by the inability to assess
where migrants are most limited – the breeding grounds, migratory stopover
sites, or wintering areas. A major challenge has been the lack of an
efficient, reliable, and broadly applicable method for measuring the
strength of migratory connections between populations across the annual
cycle. Here we show how high-resolution genetic markers can be used to
identify genetically distinct groups of a migratory bird, the
Wilson's warbler (Cardellina pusilla), at fine enough spatial scales
to facilitate assessing regional drivers of demographic trends. By
screening 1626 samples using 96 highly divergent single nucleotide
polymorphisms (SNPs) selected from a large pool of candidates (~450,000),
we identify novel region-specific migratory routes and timetables of
migration along the Pacific Flyway. Our results illustrate that
high-resolution genetic markers are more reliable, precise, and amenable
to high throughput screening than previously described intrinsic marking
techniques, making them broadly applicable to large-scale monitoring and
conservation of migratory organisms.