Taurus my dad has been having an ongoing battle with the crows for the past year. Its a kind of family joke now
Since he retired his daily routine is feeding the birds in the garden and photographing them. But the crows were knocking open the bird feeder and scaring away the finches and smaller birds.
He found a dead crow on the road and hung it upside down in the garden and that was the end of the crows for about a week. Of course the thing stunk to high heaven

- Postman must have thought he'd gone mad.
But then they came back - so next he got a figure of an owl. It was about a foot high - the type you'd get in a gardening shop. And he put it on top of the fence post - no crows for another while, but he relised they copped on it wasn't real as it didn't move (crows are intelligent birds), so now he moves the owl around once a week. He just puts it on a different post or moves it a few feet, and so far its worked. He's delighted (was becoming slightly obsessed with his ventetta against the crows), but maybe you could try that??
Another thing that works is windchimes - the shinier the better. Let me know how you get on
