Martin Kapun

The genetic structure of Slovakian Bee-eaters (Merops apiaster): Microsatellite differentiation between individuals and colonies

A highly restricted availability of nesting sites such as found in European Bee-eaters (Merops apiaster) may represent a major factor for the evolution of colony breeding. Spatially distinct colonies with breeding pairs characterized by high site fidelity should promote genetic differentiation. The species is limited to arid environments, where it digs breeding holes in sandy cliffs. European Bee-eaters are long-distance migrants. While western European populations migrate along the western coastline of Africa to their wintering areas, Eastern European and Asian populations migrate over the Sinai Peninsula towards their wintering grounds in the eastern part of Africa. The aim of this study was to estimate the degree of genetic substructure among 165 individuals from seven Bee-eater colonies from Slovakia and one colony from Spain. Five microsatellite loci were used for assigning all individual birds to colonies and to quantify genetic similarity between the colonies. ST, RST and five genetic distance coefficients provided similar results indicating very little differentiation between most of the Slovakian colonies except for one nesting site. The Spanish nesting site showed a pronounced genetic differentiation compared to all Slovakian colonies indicating a possible genetic isolation between Western and Eastern Bee-eater colonies. Slovakian Bee-eaters appear to have a high dispersal rate probably caused by destruction of nesting sites through erosion and vegetation growth and to avoid high inbreeding caused by small colony sizes.