Low levels of hybridization between domestic and wild Mallards wintering in the Lower Mississippi Flyway

Mallard ducks are a ubiquitous and socio-economically important game bird in North America. Despite their generally abundant midcontinent population, Mallards in eastern North America are declining, which may be partially explained by extensive hybridization with human-released domestically-derived game-farm Mallards. We investigated the genetic composition of Mallards in the middle and lower Mississippi flyway, key wintering regions for the species. We found that nearly 30% of wild Mallards carried mitochondrial haplotypes derived from domestic mallards present in North America, indicating that the individuals had female game-farm Mallard lineage in their past; however nuclear results identified only 4% of the same sample set as putative hybrids. Recovering 30% of samples with OW A mtDNA haplotypes is concordant with general trends across the Mississippi flyway and this percentage was stable across Mallards we sampled a decade apart. The capture and perpetuation of OW A mtDNA haplotype...