We have foxes about, and they are very bold... they do steer clear of the dogs though, so don't come into the garden much :?
I have raised the fencing around the bunny's run to 8ft now (they are never in in unsupervised anyway) and I only let the fosters into their run when I am in the garden, or can see them through the french windows (which are kept open). All hutches have bolts too - can't take any chances.
Jill - Buzzards are spreading east... they were, until recently, predominantly in Wales and the west. So, people in the mids/east - it is a good idea to keep your eye out for them, even if you have not traditionally seen them about. (They are a lot larger than kestrel, tend to circle in the air high up and their wing tips are usually pointed up a bit.)