I haven't seen any hawks near our house, but there are crows. And I would worry as much about them as I would a hawk. I once tried to rescue a pigeon that I found in the work parking lot, but the poor thing was pecked too much, probably by a crow according to the guy at the wildlife rescue.
And really, do we want to even venture and test even a little bit of caffeine on a lovebird, mine doesn't need any :P