White Wagtail déjà vu on Beeley Moor

Having seen a completely unexpected White Wagtail on Beeley Moor at this time last year I have a habit of closely scrutinising all the wagtails I get a decent view of. I was still very surprised to come across another pale backed 'alba' wagtail and even more so to see it in the same place as last year on the edge of Beeley Moor. In fact, I think it is too much of a coincidence and am inclined to the view that it is the same bird, a year older.

White Wagtail - adult male

Last year I decided that the bird was in it's first summer as both juvenile, post juvenile and pre-breeding greater coverts could be identified in the wing. This bird looks like an adult with just two ages of feather in the median and greater coverts which is typical of an adult bird. As last year, this bird looks like a male with a sharp division between the black of the nape and the grey of the mantle. 

It appeared to be with a female Pied Wagtail and both birds were collecting and flying off with food so obviously feeding young nearby. Last year the female was also rather pale backed but this year the female looks to be a typical Pied.

Pied Wagtail - adult female

I'm calling the bird a White Wagtail but it's impossible to be certain, it could be a hybrid but must surely have some White Wagtail in it.

Another interesting feature when comparing these two birds was that the Pied shows black sides to the upper breast in the shoulder area giving a continuous black breast band whereas the White had white sides to the breast, with some black spotting so the breast band is more isolated appearing as a bib rather than a continuous band.

Pied Wagtail female v White Wagtail male