2019 Volume 15 Pages A15-A22
We tracked 16 Mallards Anas platyrhynchos and 2 Spot-billed Ducks A. zonorhyncha wintering around Lake Izunuma-Uchinuma, northern Japan, by using GPS-TX in 2017/18 and 2018/19 to determine their habitat use through day and night. Mallards showed diurnal resting and nocturnal activity patterns. The nocturnal foraging patterns of both eight male and eight female Mallards varied among individuals, and some of them stayed in the lake while other ducks were distributed in lotus fields, flooded paddy fields, pond and a river north of the lake. Spot-billed Ducks also showed diurnal resting and nocturnal activity patterns. They were distributed in narrow-width irrigation canals, lotus fields, and flooded paddy fields north of the lake. The two species demonstrated some overlap site use, but Mallards did not use narrow irrigation canals. Use of GPS-TX was a powerful method to track waterfowl in the local landscape, and hereafter we intend to investigate the two species' wintering ecology.
