Lunarz - I, too, try to encourage wildlife into the garden: bug boxes for the winter, nesting boxes (sadly unused this year) for the small birds, ivy retained for insects and small birds (wrens especially like the habitat) and careful selection of plants to provide as much nectar/pollen as possible (single-flowered rather than double-flowered for example).
The corvids are very useful - they clear the roads of the inevitable roadkill, and in sensible numbers are simply part of the balanced ecology. Likewise raptors that prey on small mammals - even the sparrow-hawk which, I am assured by the RSPB, is a good indicator of plentiful small birds. Inicidentally, I haven't seen one of those for some time - so fewer small birds have had an effect there, too.
I don't get great numbers of starlings, though I know they can be bullies at the bird table. Just a case of balance really.
btw I have had few rather cross rooks today 'cos they are finding it more difficult to get at the bird feeders. round 1 to me and the little birds 