Not sure how to use this forum - my first time. Anyway, I have a single yellow wagtail visit my garden in Nottingham. Given that they should migrate to Africa at this time of year and that they are on the red list, should I report this sighting to anyone?
For reference, here is a photo of a Grey Wagtail for you to compare to the bird you saw which as Rob says, it is most likely to have been
For further comparison with Hazel's photo, this is a male Yellow Wagtail.