Phylogeography and population structure of Kruper's Nuthatch Sitta krueperi from Turkey based on microsatellites and mitochondrial DNA

Kruper's Nuthatch Sitta krueperi is endemic to Anatolia, Lesvos Island and the western Caucasus region where it inhabits coniferous forests. To infer the phylogeographic structure of Kruper's Nuthatch, we analyzed partial sequences of the mitochondrial cytochrome oxidase subunit I gene (COI; 605 bp) and allele variation at eight microsatellite loci from birds sampled across five localities in Turkey. A total of ten COI haplotypes were found among 68 individuals revealing three distinct haplotype groups; one each in northwestern, northeastern, and southern Turkey. However, there was evidence for secondary gene flow between the northwestern and the other two regions. Significant microsatellite differentiation was also found between northern and southern localities, but not between the two northern ones. This genetic structure is consistent with the isolation of these populations in different glacial refugia followed by establishing secondary contact after glacial retreat. The identified populations of this 'near threatened' species should be treated as separate conservation units.