Discovered during farmland bird surveys in Warwickshire 17/05/10 this bird hung around for several weeks and seemed to be trying to muscle in on the local pair of flavissima. The pale lavender blue colour of the head is the best feature for identifying Channel Wagtail. The pattern of the supercillia and ear coverts appear to vary somewhat in pure flava but the white sub-ocular patch is another useful pointer with hybrids showing white which extends right back along the ear coverts isolating the front lower edge of the ear coverts to the extent that it resembles a moustachial stripe. Female Channel and Blue-headed Wagtails are inseparable. In the Midlands Blue-headed Wagtail typically turns up at reservoirs and gravel pits known to attract passage migrants whereas Channel Wagtails tend to be found in arable farmland breeding, or attempting to breed with flavissima.
Channel Wagtail Motacilla flava x flavissima. Note the pale lavender blue head colour, supercillium flaring extensively behind the eye and the extensive white sub-ocular patch which breaks the lower edge of the ear-coverts.
Blue-headed Wagtail Motacilla flava flava Draycote Water 20/04/12, photo by Bob Hazell. Note the dark head and even width supercillium but note also the white sub-ocular patch.