This looks like a crow to me – mind you so do all the other black birds – except the blackbird of course. This guy was on his own in the field. There was another black bird quite a distance away – certainly not within caw-ling distance. At one time, in my slothful youth, when I noticed one of these guys pacing along the grass verge as I drove past in the car – I always imagined that they had probably dropped a contact lens somewhere and were doing their best to find it with only one eye. On closer acquaintance I now know that this is not the case. Nor are they lost in deep philosophical ruminations.
No, they are just grumpy old sods that find other people irritating.
Track and Hedge 