Relationship between waterbird distribution and environmental factors in irrigation ponds on southern Awaji Island, Hyogo Prefecture, central Japan

摘要

From January to March 2002 we investigated waterbird communities at 52 irrigation on southern Awaji Island, in Hyogo Prefecture, central Japan. Sixteen species and 277 individuals were recorded. There was no significant correlation between the number of individuals and pond surface area, but there was a significant correlation between number of species and pond surface area. We divided the ponds into three groups on the basis of waterbird distribution. Five environmental factors—pond surface area, maximum volume of water stored, pond structure type, proportion of bank covered with concrete, and presence of trees and/or shrubs adjacent to a pond—were compared between the three groups. No significant relationships between waterbird distribution and any environmental factor, with the exception of pond surface area, were detected. The distribution of waterbirds did not show a nestedness pattern.