Abstract
Winter waterfowl assemblage structure in nine dam lakes located in Kinki district, central Japan, was analysed in relation to various lake environmental properties, such as water quality, surrounding vegetation and management practices. Most waterfowl recorded in the dam lakes (41.4-100% of the total count) were the mandarin ducks and dabbling ducks, especially mallards, whereas aquatic plant and benthos consumers, such as tufted ducks and European pochards, were few. Important factors affecting waterfowl assemblage structure (richness and diversity) were surrounding vegetation and lake water level, both of which can be controlled by dam managers. The water quality or eutrophic level had little effect on waterfowl assemblage structure. These results suggest that waterfowl assemblage structure in dam lakes is greatly affected by human management. Therefore, dam managers should carefully plan their management activities so that the appropriate environment is maintained for waterfowl assemblages in dam lakes.
