What is it?

[oldchemist]

I had a brief sighting of a bird a bit smaller than a thrush, all white except for a dark bar on the wing and I think a crest on the head. It flew up from a roadside ditch/verge, perched briefly on a fence post then dropped into the field beyond. Can't see anything similar on bird ID websites.

[Ballymore]

Could it have been a male Snow bunting?
Here's the link to RSPB birdidentifier - it may help you.

http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/birdidentifier/

[oldchemist]

It was whiter and slimmer in the body than the RSPB image. I wonder if it is an escaped exotic?

[Kenn]

Shrike ?
There have been a few about this winter.

[Braders]

I love that bird RSPB site that is awesome