Habitat type does not affect population genetic structure in sympatric great tits (Parus major) and blue tits (P. caeruleus)
Populations of two sympatric Parus species, the great tit (Parus major) and the blue tit (Parus caeruleus), were studied in deciduous and mixed-coniferous forests in southwestern Germany. We analysed the genetic variation of microsatellite and allozyme loci within and among populations to infer dispersal and potential source-sink dynamics in populations of both species that live in different habitat types. The genetic structure was found to be homogeneous across local populations of both species within years and genetic variation differed among years. The homogeneous genetic pattern among habitats suggests high migration and dispersal rates. Despite considerable differences in the breeding performance of individuals from different habitat types, there is no strong genetic evidence for source-sink dynamics in southwestern German populations of the great tit and the blue tit.