Small black and white bird
No interactions present.
You could go even closer on this one, the black back and dusky flanks make this as you say a Pied Wagtail - Motacilla alba subsp. yarrellii
Chris Brooks - www.dragonfly-images.co.uk
My Flickr site - www.flickr.com/photos/ceb1298
Thanks Chris, I wasn't sure about the subspecies.
Lat/Lng: 54.591, -3.138
OS grid ref: NY265223