White Wagtail
APRIL is the classic time for seeing a White Wagtail in Britain. White and Pied Wagtails are subspecies that are best separated in spring and summer, when males, at least, are distinctive.
In autumn and winter, the wagtails we see on ploughed fields, around farm livestock, on freshwater margins or along the beach tend to be passed off as Pied – but maybe they deserve a second look. In some areas, it seems that White Wagtails might be relatively frequent.
The plumages in autumn can be confusing. The best feature to look for is the rump. Beware the uppertail coverts, which look blackish on both subspecies; the rump is a bit higher towards the back, and is grey on a White Wagtail, blacker or mixed with black on Pieds. Adult Pied has black on the crown and nape; this is olive-grey with little or no black on White. Pied’s flanks are dark grey, these are pale on White.
While juveniles are inseparable, by now first-winters can be worked out with care: Pied has a white or yellowish forehead, all-black crown and usually a black nape. White has a grey crown, which is edged black at the front on the male so overlapping with Pied, but grey with just a narrow white forehead on the female. First-winter Pied has a broad black breastband and dark flanks, a grey back recalling White Wagtail, but a black or blackish rump. White has a narrow breastband and bright white underparts with pale grey flanks, olive-grey back and darker grey rump blending into blacker tail coverts.
There are, however, individual variations that produce birds with mixed or contradictory features, so autumn/winter White Wagtails in the UK can be a challenge. Have fun!