The colonization history and present-day population structure of the European great tit (Parus major major)

The colonization history and present-day population structure of the Europe an subspecies of the great tit Parus major major were studied using mitocho ndrial control region sequences. One major haplotype was found in all but o ne of the eight sampled populations from Spain to northern Finland. The oth er haplotypes differed from the common one by just a few substitutions; the overall nucleotide diversity was 0.00187 and haplotype diversity 0.8633. N o population structuring was detected. The mismatch distribution followed t he expected distribution of an expanding population. The estimated time to the most recent common ancestor coincides with the last glacial period. The results suggest that P. m. major survived the last glacial period in a sin gle isolated refuge probably by the Mediterranean Sea. This was followed by rapid colonization of the European continent and population growth. The mo st recent range expansion northwards is still occurring. Gene flow between the sampled populations is extensive. It is aided by juvenile dispersal, lo ng-distance movements of juvenile flocks and partial migration in the north ern parts of the great tit's range.