Crow deterrence

The croquet lawns here on Glasgow are converted bowling greens. The bowlers have two greens and the croquet players also have two. All four lawns suffer from being attacked by crows. The bowlers claim the holes in their lawns are made by croquet players putting in the hoops, but we don't use their lawns. Hoops leave 2 holes: the birds have not mastered pecking out pairs of holes even on the bowlers grass.
But the damage they can do is real. So to protect the holes for our croquet hoops, so the birds do not expand them, the club covers them with wire mesh covers.
Now bowlers are happy and birds unhappy; not vice versa!