ヒドリガモ
A fieldwork study at Hyo-ko Waterfowl Park, a nature preserve in Niigata, Japan, found what they presumed was a male hybrid of a falcated duck and a Eurasian wigeon. They have found these “wild” hybrids in several instances over the past few years. These birds shared morphological traits with both species. Still, most of the traits favored the falcated duck. It was reported that these hybrid birds have joined courting parties of Eurasian wigeon and even attempted to compete with wigeon males. Grunt-whistling, and burping calls being the method of inciting courtship, even resemble that of the falcated duck and not of the Eurasian wigeon. The hybrid bird most be closely watched, was quite sexually active, however, it is not yet known if they can reproduce with either of the female species.