Connectivity and genetic diversity of wintering Common Pochards (Aythya ferina; Linnaeus, 1758) in Iran

Genetic studies provide the cornerstone for understanding the genetic adaptations and population dynamics of the common pochard (Aythya ferina) and, consequently, for designing effective conservation strategies to ensure its long-term survival. This study investigated the genetic diversity of the common pochard in Iran using mitochondrial DNA (mtDNA) sequences (cytb and D-loop) from two wintering sites: the southern Caspian Sea and the Hor al-Azim wetland. Analysis of 30 D-loop sequences revealed 6 distinct haplotypes, with 5 found in Iran and 1 from China. Analysis of 30 cytb sequences identified 3 haplotypes, with 2 found in northern Iran and 1 shared by southern Iran and other regions. Low genetic diversity was observed within the Iranian population, with an average haplotype diversity of 0.109 for both genes. Tajima's D and Fu's FS tests did not show significant deviations from neutrality, suggesting past population expansion. Phylogenetic analysis revealed that Iranian pochards are closely related to populations from Europe and East Asia, indicating that these regions contribute to the Iranian wintering population. The low genetic distance and high gene flow observed among the studied samples, while indicative of connectivity between populations, likely reflects the mixing of individuals from diverse breeding origins rather than active gene exchange within the Iranian wintering sites, given the limited evidence of breeding in Iran. These findings highlight the importance of conserving Iran's wetlands as habitats for the common pochard, alongside preventing illegal hunting, to maintain connectivity among populations and ensure the conservation of gene flow and genetic diversity for the long-term survival of this species.