Western yellow wagtail

　The Western yellow wagtail passes through the Nansei Islands from late August through to October. Although it breeds in northern Hokkaido, it is a rare migratory bird on Honshu.

　In the rice fields of Hiratabaru on Ishigaki Island, large flocks of over 100 birds can be seen, mainly in autumn. During the migration period, they often travel in large flocks; I recall being overwhelmed in Senegal, where I was staying, by a flock of several hundred Western yellow wagtails that had migrated from Europe and were resting at the harbour.

　Although they are widely distributed from the Eurasian continent to the African continent, there are significant regional variations, and they are classified into 10–12 subspecies. The photograph shows the subspecies *Motacilla flava simillima*, characterised by its white eyebrow stripe. Whilst subspecies can be easily distinguished in summer plumage due to differences in colouration, there is almost no difference in winter plumage, making identification in the field difficult.