About Zosterops erythropleurus Swinhoe, 1863
This species measures 10.5 cm in overall length, and has a distinct chestnut patch on its flanks. The base of the bill and the lower mandible may be pinkish, and its underparts are a cleaner white. The similar-looking Japanese white-eye has pale brown flanks, in contrast to this species. It is a migratory bird, the most migratory species among all white-eyes. It breeds in Manchuria, and migrates to central China, Yunnan Province, and northern Southeast Asia for the winter. Its breeding habitats are poplar, alder, and willow forests, thickets, and groves. During the winter, it occupies deciduous and evergreen forests, usually at elevations above 1000 m.
