Localities. Map of localities where males of the Thrush Nightingale (Luscinia luscinia) and the Common Nightingale (Luscinia megarhynchos) were sampled. White - allopatric range of L. megarhynchos, dark grey - allopatric range of L. luscinia, light grey - range overlap of both species (i.e., sympatry). Species' ranges are redrawn with modifications from Sorjonen , Cramp  and Hagemeijer and Blair .
Reifová et al. BMC Evolutionary Biology 2011 11:138 doi:10.1186/1471-2148-11-138