MtDNA analysis
Aligned sequences of a 381 bp section of the control region (CR) (n=224 individuals) and a 370 bp section of the cytochrome B gene (cytb ) (n=228 individuals) were obtained. The CR was more polymorphic revealing 21 haplotypes compared to cytb, where only five haplotypes were detected. A total of 204 individuals have been sequenced at both regions and the mitochondrial diversity estimates of the combined sequences (751 bp in total) were summarized in Table 1. A total of 24 haplotypes (h) were observed, with 11 found within the wild UK birds and six within the wild Greek birds. Our dataset revealed that there was greater mitochondrial diversity within the wild UK birds (haplotype diversity = 0.776) than within the wild Greek birds (haplotype diversity = 0.439). This pattern was also mirrored within the captive stocks of both countries, with the UK captive stocks (hd=0.786) having a higher diversity than the Greek captive stocks (hd=0.409). Surprisingly, the wild-caught birds from North Macedonia had the highest haplotype diversity (hd=0.833). The three sampling locations with the highest haplotype diversity were all from different countries, East Lothian (hd=0.868; Scotland), Kumanovo (hd=0.822; North Macedonia) and Kozani (hd=0.757; Greece). This is contrasted with the two lowest estimates, also from different countries, Fife (hd=0.182; Scotland) and Drama (hd=0; Greece).
The haplotype networks revealed and confirmed the eastern and western lineages in both the cytb and CR sequences (Figures 2 and 3). The inclusion of the haplotypes by (Liukkonen-Anttila et al. , 2002) in our network of the control region sequences, verified the structuring of our samples into the Western and Eastern lineages since all wild birds in the UK had a western mitochondrial haplotype while all wild birds in Greece showed an Eastern haplotype. The two populations from North Macedonia had a mix of birds as indicated by the networks, based on the CR data, most of the birds had an eastern haplotype (69%, n=11) and some possessed a western haplotype (31%, n=5).
The analysis also revealed that 17 new haplotypes (eight western and nine Eastern) exist within our control-region dataset that were not observed by the previous study. The most striking observation is the clustering of all Greek captive individuals within the Western lineage, showing higher relatedness with the wild birds from the UK rather than those in Greece.