I think it is a Pale Thrush
I can see why Grey-sided Thrush has been suggested for this bird but it looks like a Pale Thrush to me for the following reasons:
- strong legs and long tail, quite a large thrush. Grey-sided is small and short-tailed like eye-browed (which takes a smaller ring size than Pale).
- head pattern not strong enough for a Grey-sided even a first winter - look at photos on the OB site. Grey-sided always show two white stripes, above and below the eye and a dark eye stripe.
- grey 'sides' can be weak in first winter Grey-sided but this is just rather dull grey below, not showing a distinction between the flanks and belly.
Mike Leven