Hybrids and mixed pairs of Syrian and Great-spotted Woodpeckers in urban populations

Abstract

The population structures of sympatric Syrian and Great-spotted Woodpeckers (SW and GW, respectively) in urban areas of Poland were investigated with respect to the occurrence of mixed pairs and hybrids. It was estimated that 5.3% of pairs were mixed and that these interspecific pairs mainly comprised SW or hybrid females and GW males. In total, 3.6% of observed individuals and 6.9% of dead birds were identified as hybrids. The sex ratio of hybrids was equal. These data suggest that hybridization between these woodpeckers could be an underestimated phenomenon with important consequences for ecological studies and conservation of the rare SW.