Study sites and data collection
We selected ten populations from across S. virens breeding
distribution to capture range-wide genomic diversity (Figure 1). During
their breeding season (April-June), we used mist nets with audio
playback of conspecific song to capture S. v. virens males in
Arkansas, Indiana, New York, central North Carolina, and Tennessee, as
well as putative S. v. waynei males in coastal North Carolina
(Table 1). For all individuals, we collected ≥50 μL of blood from the
brachial vein, which was stored in either Queen’s Lysis buffer or
ethanol (Seutin et al., 1991). In addition, two S. v. virenstissue samples from New York were donated by The Cornell University
Museum of Vertebrates.