Genomic data reveal mixed support for the current subspecies designations in the <i>Megascops asio</i> (Eastern Screech-Owl)

Abstract Megascops asio (Eastern Screech-Owl) is a nonmigratory resident forest owl that occurs across a broad distribution throughout much of eastern and central North America with 5 subspecies generally recognized across the range. Using reduced representation sequencing, we found that genetic differentiation among populations was generally low, with only 2 clear genetic clusters supporting that M. a. mccallii is distinct. Beyond these 2 main groups, we found subtle genetic clustering roughly corresponding to geographic region and the currently recognized subspecies, suggesting mixed support for current subspecies designations. To address these questions, we analyzed 228 individuals representing all 5 recognized subspecies at 8,220 single-nucleotide polymorphisms using standard population genetic approaches. In addition to the subtle population structuring noted above, the genetically identified subpopulations also varied in estimated effective population sizes and metrics of genetic diversity. We also detected a weak, but significant, signal of isolation by distance across the range, suggesting clinal patterns of genetic variation across this broadly distributed species. The genetic population structure we uncovered broadens our understanding of subspecies-level taxonomic classification in this species and may be useful for effective conservation management if it becomes necessary.