Figure 2

Seasonal variations in (a) the mean number of detected song units per hour on the west side of Chichijima Island; (b) the mean number of detected song units per hour on the east side of Chichijima Island; and (c) the mean number of detected singers per hour on the west side of Chichijima Island. The gray parts in (a) and (c) indicate that there is no data because recordings were not performed. Note that the y-axis scale is different in each graph.