California gnatcatcher, Polioptila californica, restriction site-associated DNA sequencing data (ddRADseq) throughout California, USA (2012-2013) and Baja California, Mexico (2018-2019)

These data were collected to assess the distribution of genetic diversity within and among occurrences of the endangered California Gnatcatcher (Polioptila californica) and explore its evolutionary relationship to recognized subspecific with adjacent distribution in Baja California, using genome-wide genetic markers. The dataset archived herein can be used to further investigate evolutionary or ecological processes that affect these sampled occurrences of Polioptila californica, or they may be used to reconfirm the patterns reported in Vandergast et al. 2022 (see Larger Work Citation).