“The point you raise _re_ the relative speed of swifts and other birds is a difficult one to decide.
“I have, however, a strong recollection of a brother falconer (I cannot remember who it was) telling me that his trained merlins could easily overhaul a swift, and he told me that once or twice they had killed them. But this was many years ago, and I am not able to remember all the facts.
“I have often stood on the bridges here and watched swifts passing in hundreds close past me. They appear to be moving very fast when hawking after flies near the surface of a river.
“There is a long stretch of broad water in the river in front of my house here, and often there are hundreds of swifts flying up and down it. They go about half a mile dead straight and then turn back over this stretch of the river.
“I have flown fast carrier pigeons along this same bit of water, and they seem to do it in less time than the swifts. Only last summer, at my place in Scotland, I was sitting on the banks of the river watching some swifts, when a pair of blue rock pigeons came from their nest in the cliff, going out to feed, and they went clean past the swifts going in the same direction.
“Of course presumably the pigeons were in a hurry and the swifts were not, and unless we are certain that both birds are trying their hardest, you cannot accept these things as a test of speed.
“If I were asked to guess roughly at the six fastest flying birds in the British Isles, I should place them as follows:
1. The Peregrine, 2. The Hobby, 3. The Merlin, 4. The Golden Plover, 5. The Pochard, 6. The Blue Rock Pigeon,
and the fastest game bird is undoubtedly the blackcock. I do not know, however, if a capercailzie would not beat him if you could get them both to take a long flight across the open, because, generally speaking, in the case of birds of similar shape and species, the heaviest bird is the fastest flying one.”
Captain G. S. Blaine, another falconer of long and varied experience, has also been so kind as to give me his opinion on this question. He writes:
“I cannot say whether a peregrine falcon could overtake and kill a swift, but I do not think it would ever attempt the feat. Falcons do not, as a rule, attack small birds. The male or tiercel will sometimes stoop at them, but more in play than in earnest. The female, I should think, would never attempt to catch anything smaller than a thrush or starling.