Population genetic structure and vocal dialects in an amazon parrot

The relationship between cultural and genetic evolution was examined in the yellow-naped amazon Amazona auropalliata. This species has previously been shown to have regional dialects defined by large shifts in the acoustic st ructure of its learned contact call. Mitochondrial DNA sequence variation f rom a 680 base pair segment of the first domain of the control region was a ssayed in 41 samples collected from two neighbouring dialects in Costa Rica . The relationship of genetic variation to vocal variation was examined usi ng haplotype analysis, genetic distance analysis, a maximum-likelihood esti mator of migration rates and phylogenetic reconstructions. All analyses ind icated a high degree of gene flow and, thus, individual dispersal across di alect boundaries. Calls sampled from sound libraries suggested that tempora lly stable contact call dialects occur throughout the range of the yellow-n aped amazon, while the presence of similar dialects in the sister species A mazona ochrocephala suggests that the propensity to form dialects is ancest ral in this clade. These results indicate that genes and culture are not cl osely associated in the yellow-naped amazon. Rather, they suggest that regi onal diversity in vocalizations is maintained by selective pressures that p romote social learning and allow individual repertoires to conform to local call types.