Twenty Far East Greylag Geese, Anser anser rubrirostris, were captured and fitted with Global Positioning System/Global System for Mobile Communications (GPS/GSM) loggers to identify breeding and wintering areas, migration routes and stopover sites. Telemetry data for the first time showed linkages between their Yangtze River wintering areas, stopover sites in northeastern China, and breeding/molting grounds in eastern Mongolia and northeast China. ). The median stopover duration was 31.1 and 51.3 days and the median speed of travel was 62.6 and 47.9 km/day for spring and autumn migration, respectively. The significant differences between spring and autumn migration on the migration duration, the stopover duration and the migration speed confirmed that tagged adult Greylag Geese traveled faster in spring than autumn, supporting the hypothesis that they should be more time-limited during spring migration.

Background: Evidence suggests that wintering waterbirds have become conspicuously more concentrated at two largest lakes of the Yangtze River Floodplain, East Dong Ting Lake (Hunan Province, 29°20′N, 113°E) and Poyang Lake (Jiangxi Province, 29°N, 116°20′E), relative to other lakes, despite the establishment of reserves elsewhere. While this relationship is likely due to greater extent of undisturbed habitats in larger lakes, we understand little of the drivers affecting individual behaviours behind this tendency. Methods:We tracked wintering movements of three duck species (Eurasian Wigeon Mareca penelope, Falcated Duck M. falcata and Northern Pintail Anas acuta) using GPS transmitters, examining differences between the two largest lakes and other smaller lakes in ducks' habitat use, duration of stay at each lake and the daily distances moved by the tagged birds while at these sites. Results:The Eurasian Wigeon and Falcated Duck stayed five times longer and almost exclusively used natural habitat types at the two large lakes (91-95% of positions) compared to length of stay time at smaller lakes, where they spent 28-33 days on average (excluding the capture site) and exploited many more different habitats (including c. 50% outside lakes). Conclusions:Our study is the first to show that shorter length of stay and more varied habitat use by ducks at small lakes may contribute to explaining the apparent regional concentration of numbers present of these and other species at the largest lakes in recent years. This compares with their declining abundance at smaller lakes, where habitat loss and degradation has been more manifest than on the larger lakes.

Summary Among the six sympatric swan and goose species wintering in the Yangtze River floodplain, only Greylag Goose Anser anser and Bean Goose A. fabalis showed increasing population trends in the last 20 years. Until now, almost nothing was known about the Greylag Geese breeding on the eastern Mongolian Plateau, which we now know mostly winter in the Yangtze River floodplain. We applied GPS transmitters to 20 Greylag Geese in the Yangtze River floodplain and eastern Mongolia, providing complete tracks of their movements in summer, winter, spring and autumn (n = 6, 8, 8, 7). We overlaid these locations on GIS layers of habitat type and national-level protected areas, and modelled their habitat selection. Geese summered in Dauria Region, Huihe National Nature Reserve, and Wulagai Wetlands (from where 55% of GPS fixes were located in protected areas), wintered in Poyang Lake, Longgan Lake, and Anqing Lakes (43%), and staged around Bohai Bay, Xila Mulun River, and Wulagai Wetlands (spring, 48%; autumn, 45%). Geese mainly used natural ecosystems in summer (essentially grasslands and wetlands/water bodies), but in the other three seasons, used croplands between 17% (spring) and 46% (winter) of the time, with most of the rest of the time spent on wetlands/water bodies. Geese were frequently associated with wetlands and areas close to lakes/wetlands in all seasons, and cropland during winter and spring/autumn migration. These results suggest Greylag Geese in this biogeographical sub-population have increasingly shifted to feeding in croplands during the non-breeding season and enjoy the benefit of using protected areas throughout the year. We infer that these factors could have potentially contributed to elevated survival and reproductive success (relatively high among sampled flocks in recent years) which could explain the favourable conservation status of this population of Greylag Geese in recent years compared to other sympatric wintering goose and swan species.