ヒドリガモ
Hybridization between two different species often leaves the offspring sterile, but this genus shows a surprising amount of hybrid fertility. This hybrid species performed courtship rituals more closely related to the falcated duck, yet socially was active in Eurasian wigeon flocks. Successful reproduction was not seen between the hybrid species and a pure Eurasian wigeon female during the fieldwork study. Further study of hybrid avian species can help shed light onto avian reproduction and their evolutionary biology.