Peregrines have several techniques for killing on the wing. The first involves bashing into a bird with the feet clenched into “fists,” knocking it out of the air (and perhaps out in general). The peregrine then retrieves the bird on the ground. In the second, the classic “stoop” kill, it swoops down on its prey from above, grasping it with its terrible talons. If the bird is small this can kill it immediately. If it doesn’t the peregrine takes the bird to ground and finishes the kill, usually with a bite that breaks its neck. Like all members of the falcon family, the peregrine has a special adaptation for breaking necks—the tomial tooth, a sharp projection on the upper beak that can sever spinal cords with a single nip:
A birdy colleague of mine pointed out that while a bite with the tomial tooth may paralyze the prey, it may not kill it, so that the prey could be plucked and eaten while still alive.
Finally, for large birds like ducks, there’s a danger of swooping in from above, since the large, flapping wings of the prey could cause an accident. But the peregrine can take these birds from below, which means flying upside down at the moment it grabs the bird. Large prey taken this way may not be killed in the air; they’re taken to ground and dispatched there.
Here’s a peregrine using the “bash” technique on a much larger red-tailed hawk (Buteo jamaicensis) that it sees as a threat to its young. I’m not sure what happened after the hawk was bashed from the air; it may very well have died.
And here’s a peregrine coming back to its trainer at high speed. The landing is a bit awkward!
Near the brook a heron lay in frozen stubble. Its wings were stuck to the ground by frost, and the mandibles of its bill were frozen together. Its eyes were open and living, the rest of it was dead. All was dead but the fear of man. As I approached I could see its whole body craving into flight. But it could not fly. I gave it peace, and saw the agonised sunlight of its eyes slowly heal with cloud.
No pain, no death, is more terrible to a wild creature than its fear of man. A red-throated diver, sodden and obscene with oil, able to move only its head, will push itself out from the sea-wall with its bill if you reach down to it as it floats like a log in the tide. A poisoned crow, gaping and helplessly floundering in the grass, bright yellow foam bubbling from its throat, will dash itself up again and again on to the descending wall of air, if you try to catch it. A rabbit, inflated and foul with myxomatosis, just a twitching pulse bleating in a bladder of bones and fur, will feel the vibration of your footstep and will look for you with bulging, sightless eyes. Then it will drag itself away into a bush, trembling with fear.
We are the killers. We stink of death. We carry it with us. It sticks to us like frost. We cannot tear it away.
—J. A. Baker, The Peregrine