Western yellow wagtail
The western yellow wagtail ("Motacilla flava") is a small passerine in the wagtail family Motacillidae, which also includes the pipits and longclaws. This species breeds in much of temperate Europe and Asia. It is resident in the milder parts of its range, such as western Europe, but northern and eastern populations migrate to Africa and south Asia. It is a slender 15–16 cm long bird, with the characteristic long, constantly wagging tail of its genus. It is the shortest tailed of the European wagtails. The breeding adult male is basically olive above and yellow below. In other  plumages, the yellow may be diluted by white. The heads of breeding males come in a variety of colours and patterns depending on subspecies. The call is a high-pitched "jeet". This insectivorous bird inhabits open country near water, such as wet meadows. It nests in tussocks, laying 4–8 speckled eggs. Systematics. "Motacilla" is the Latin name for the wagtail; although actually a diminutive of "motare", " to move about", from medieval times it led to the misunderstanding of "cilla" as "tail". The specific "flava" is Latin for golden-yellow. This species' systematics and phylogeny is extremely confusing. Dozens of subspecies  have been described at one time or another, and some 15-20 are currently considered valid depending on which author reviews them. In addition, the citrine wagtail ("M. citreola") forms a cryptic species complex with this bird; both taxa as conventionally delimited are paraphyletic in respect to each other. The populations of the Beringian region are sometimes separated as eastern yellow wagtail ("M. tschutschensis"). Currently recognized subspecies. Colouration refers to males except when noted. The nominate blue-headed wagtail and yellow wagtail form a narrow hybrid zone in northern France. Birds from this zone vary in appearance, but one type , which resembles nominate blue-headed wagtail (except that the blue tones to the head are paler and more mauve and the white of the head is more extensive, particularly on the throat, ear-coverts, and supercilium) is colloquially referred to as Channel wagtail. In culture. In the Pyramid Texts of Old Kingdom Egypt, the yellow wagtail was considered a representation of Atum himself and might have been the first inspiration for the Bennu bird, which, in turn, is the supposed inspiration for the phoenix of Greek mythology.