For a couple of years ago we've had a sparrow hawk who sits in on of the big trees as the back of our garden. She (I looked her up in a bird book) sat imperiously, deciding which of the several bird tables would provide her next snack. I came into the kitchen one day, to see her sitting under the bird table, with the body of a pigeon in her mouth, its feathers were on the ground around her. Watching her, watching me, and then her takeoff, slowly, her snack safely in her mouth was a memorable experience. i've accepted the pigeons will be regular visitors, but it's worth it to have all the finches, thrushes, black birds and others around as well.