Abstract
We determined the habitat selection of Whooper Swan Cygnus cygnus, Northern Pintail Anas acuta and Mallard A. platyrhynchos wintering around Lake Izunuma-Uchinuma, northern Japan, by using Global Positioning System (GPS) tracking during the winters of 2015/16 and 2017/18. The GPS device, GPS-TX (Mathematical Assist Design Laboratory) is attached to the bird and transmits the location data to a base station so that the bird does not have to be recaptured to retrieve the data. Whooper Swans showed a diurnal foraging pattern and were located in open water where lotus was abundant, and at an artificial feeding area in Lake Izunuma-Uchinuma. A smaller number of observations were from paddy fields around the lake. Northern Pintails showed the characteristics of both diurnal and nocturnal activity patterns. Pintails in 2015/16 mainly stayed in the artificial feeding area during the day, and some of them moved to the paddy fields to the north and east of the lake at night. The distance from the lake to these paddy fields was an average of 2.5km. Pintails in 2017/18 remained in the artificial feeding area, and during the day they stayed close to the parking lot where people fed the ducks. Mallards showed a nocturnal activity pattern, as they moved to the paddy fields to the north of the lake at night. The distance from the lake to the paddy fields where Mallards stayed at night was an average of 4.5km. Of the farmland surrounding Lake Izunuma-Uchinuma, Whooper Swans and Northern Pintails selected to use dried paddy fields, but Mallards used flooded paddy fields. GPS-TX was shown to be a useful technology to track waterfowl, and hereafter is expected to shed light on wintering ecology
