Abstract
From April to June, 1991, the number of Whimbrels (Numenius phaeopus) were counted at Yatsu tidal flat, Narashino, Chiba, in central Honshu (35°41′N.140°00′E). During the spring migration, the first Whimbrel was seen on 17th April. From the first arrival, Whimbrels increased rapidly in number. The peak occurred on 10th May when 522 birds were seen roosting in a flock. After the peak, the number of birds soon decreased. In July no birds were observed in the study area.
