Waste not, want not: microsatellites remain an economical and informative technology for conservation genetics

Comparisons of microsatellite and single-nucleotide polymorphisms (SNPs) have found that SNPs outperform microsatellites in population genetic analyses, calling into the question the continued utility of microsatellites in population and landscape genetics. Yet highly polymorphic markers may be of value in species that have reduced genetic variation. This study repeated analyses previously done using microsatellites with SNPs developed from ddRAD sequencing in the black-capped vireo source-sink system. SNPs provided greater resolution of genetic diversity, population differentiation, and migrant detection but could not reconstruct parentage relationships due to insufficient heterozygosities. The biological inferences made by both sets of markers were similar: asymmetrical gene flow from source populations to the remaining sink populations. With the landscape genetic analyses, we found different results between the two molecular markers, but associations of the top environmental features (riparian, open habitat, agriculture, and human development) with dispersal estimates were shared between marker types. Despite the higher precision of SNPs, we find that microsatellites effectively uncover population processes and patterns and are superior for parentage analyses in this species with reduced genetic diversity. This study illustrates the continued applicability and relevance of microsatellites in population genetic research.