Male yellow wagtail, delicately stepping

https://www.flickr.com/photos/davea2007/albums/72157694570248715

Male yellow wagtail, delicately stepping forward as it searched for insects to eat. First it was on a riverside path. A dogwalker came along so it flew to where the current had concentrated a patch of flotsam, and started pacing there instead.

CORRECTION: there’s a patch of yellow in the bird’s plumage. That makes it a grey wagtail, as eny fule noe.