Defining conservation units
We applied the framework of Funk et al. (2012) to identify evolutionary significant units (ESUs), management units (MUs) and adaptive units (AU). ESUs were delineated based on the population structure detected using all loci. MUs were delineated based on neutral loci in HWE to detect demographically independent units. AUs were delineated using loci identified as adaptive using the methods outlined above. Assignment to different groups within each conservation unit type was based on visual inspection of the PCAs, accounting for all significant PC axes. For ESU definition we also considered mitochondrial DNA data from other studies (Hoisington 2007; Hoisington-Lopez et al. 2012), which tends to reflect biogeographic patterns at the levels of intermediate to distant past (Zink & Barrowclough 2008), and for MUs we also considered the proportion of assignment to the K inferred populations, supported by levels of population differentiation,F ST (Palsbøll et al. 2006).