Breeding origin and migration pattern of dunlin (Calidris alpina) revealedby mitochondrial DNA analysis.

The large-scale migration of birds has been studied extensively by recoveri es of ringed birds. However, there is very little ringing data from the arc tic breeding grounds of waders. Here, the migration pattern of the dunlin, Calidris alpina, is studied with population genetic markers, using haplotyp e frequencies to estimate the breeding origin of migrating and wintering po pulations. Polymerase chain reaction (PCR) and restriction analysis of DNA from the mitochondrial control region was used to study the breeding origin s of morphologically similar winter populations in the western Palaearctic, and to describe the population structure of the dunlin during winter. Also migrating dunlin from various stopover sites in Europe, Africa and Asia, w ere analysed with respect to their mitochondrial DNA (mtDNA) haplotypes. Th e genetic markers clearly show that the dunlin has a parallel migration sys tem, with populations breeding in the western Palaearctic wintering mainly in the western part of the wintering range, and dunlin populations breeding further east wintering further east. The results also show that the distan ce between breeding and wintering area increases eastwards in this region.