春秋の渡り期におけるムナグロの水田から芝草地への夕刻の移動.

At Okubo rice fields, located in the lower Arakawa Valley in the Kanto Plain of Central Japan, we observed the movements of Pacific Golden Plovers Pluvialis fulva from the rice fields to lawn areas in the evening during the spring and autumn migration season in 1987. During the spring season in early April before spring farming, and in the autumn season from September to October after harvesting, we observed that Pacific Golden Plovers moved from rice fields to lawn areas in the evening. However, from mid-April to May, after the start of spring farming, many individuals remained in rice fields without moving to lawn areas in the evening. Our observation using night vision scopes revealed that the Pacific Golden Plovers were foraging in the nighttime for two nights at the lawn areas, thus suggesting the importance of lawn areas as foraging sites at nighttime. [ABSTRACT FROM AUTHOR]