Yellowhammer

He and all this family were hiding in the grass verge and every time I drove a few feet closer they'd up en-masse and fly a few feet further on. They tuck themselves into the grass so well (and they're so small) that it can be really hard to spot them for all that they are bright yellow. Wish I'd had my big lens with me.

I'm pretty sure he's a yellowhammer though I can't guarantee it. I'm perfectly happy to be told if it's actually a yellowhead - not likely though as they are a lot rarer and generally live high up in bush.