Western Yellow Wagtail

The western yellow wagtail is a slender bird 15–16 centimetres long, with the characteristic long, constantly wagging tail of its genus, and is the shortest-tailed of the European wagtails. The breeding adult male is basically olive above and yellow below. In other plumages, particularly juveniles, the yellow may be diluted to whitish. Ten subspecies are recognised, distinguished mainly by male head colour; females are often hard or impossible to identify to subspecies. (Wikipedia, general species account)

The species breeds in much of temperate Europe and Asia. Most populations are migratory, moving south to tropical Africa and southern Asia for the winter, though the small population breeding in Egypt is resident. Where the nominate blue-headed and yellow wagtails meet in northern France they form a narrow hybrid zone, and one hybrid type is known colloquially as the Channel wagtail. (Wikipedia, general species account)