Yellowhammer

I couldn't work out what the piercing, unusual song was that was waking me at dawn. I could just make out the guilty bird, perched on a twig atop next door's graceful silver birch. Then yesterday a very odd looking bird was pecking at crumbs on the lawn. I grabbed the binoculars and noted the yellowish colouring and the fluffy, speckled breast. When I looked it up, it was, of course, a yellowhammer. I had never seen one before and was quite thrilled. This one holds its tail quite high and flicks it every so often like a wagtail would do. Is this a quirk of this individual bird, I wonder, or do they all do it? Anybody know?