Variation in spring migration routes and breeding distribution of northern pintails Anas acuta that winter in Japan - Hupp, Jerry; Yamaguchi, Noriyuki; Flint, Paul; Pearce, John; Tokita, Ken-ichi; Shimada, Tetsuo; Ramey, Andrew; Kharitonov, Sergei; Higuchi, Hiroyoshi (Journal of Avian Biology, 2011)