Whilst birding the Jubail area I came across a large group of wagtails including Yellow Wagtails, White Wagtails and Citrine Wagtails. In amongst the mainly Black-headed Yellow Wagtails I saw briefly a superciliaris type bird. I managed to get a single photo of it before it flew off and could see it had many features of the intergrade but the head was less dark than the only other bird I have seen of this type.
Yellow Wagtail Motacilla flava supeciliaris are an intergrade between feldegg (Black-headed Wagtail) and lutea (Yellow-headed Wagtail), flava (Blue-headed Wagtail) or beema (Sykes’s Wagtail). They resemble feldegg except for having a conspicuous pale supercilium and pale eye-ring, although the eye-ring is not always present.
The supercilium also varies in colour from yellow to white with birds with white supercilium called ‘superciliaris’ and those with yellow ‘xanthophrys’. They are reported to be a rather frequent intergrade.