Small bird long tail feathers, Ventimiglia, It, Dec (1 Viewer)

This was one I didn't realise I had taken - it was in fact a shot of the river mouth, and I've just noticed there was a small bird flying across the bottom of the picture. Although it's just a silhouette, the long tail feathers might make it recognisable? Absolutely no clue, I've examined every page in Collins, and can't find anything that seems to fit. I initially thought kingfisher, because I had seen one there earlier, but it's obviously totally wrong for that.

Colours impossible to tell - silhouette with gleams... Head and bill look chat-like...??

Tail looks pretty long indeed, so maybe it was a Wagtail. I suppose that candidates would be Pied, White and Grey Wagtails.