Populations change of the Bean Goose (Anser fabalis) wintering at the Upo Wetland, Korea

The wintering population of Bean Goose (Anser fabalis) at the Upo Wetland from 2005 to 2010 has been monitoredby the long term ecological research (LTER) project in South Korea. The principal objective of this study was to definethe primary factors determining the wintering Bean Goose population distribution in the wetland system, such as: usagepattern of habitat in and around the Upo Wetland, and departure timing related to temperature. We conducted acomprehensive literature review regarding Bean Goose population dominance in the wetland, and there was a cleartendency toward an increase in this species’ dominance until 2002. The LTER monitoring data also exhibited a similartrend, but not as strongly as was seen in previous research. When the Bean Goose population arrived at the Upo Wetland,they utilized the wetland as their resting site, while they moved to other places surrounding the wetlands to forage forfood sources. The flight distance of the Bean Goose for feeding ranged between ca 1 to 25 km from the Upo area. Thepopulation changes of the Bean Goose at the Upo were related to the lowest temperatures in winter (r = -0.461, P = 0.009).In particular, the lowest temperature in March was important for creating flocks of the Bean Goose before returning tothe northern region. The results of this study can provide us with basic information regarding migratory bird populationchanges in the Upo Wetland in relation to the land use patterns of human beings, as well as meteorological variations.