Part 3
Again in reference to the difference of opinion as to whether the teal is faster than the mallard, may it not be possible that both views may be correct? in other words, that it depends upon the length of flight which the writer is considering. It may be noticed that Major Radclyffe in the passage which I have quoted above (p. 28) seems to consider it may be possible that for a short distance the teal may be faster than the mallard, though he has no doubt that the latter bird will very soon overtake the former.
The falconer has certainly more and better opportunities of seeing birds flying at their maximum rate of speed than any one else. “He also has,” to use Captain Portal’s words, “the advantage of possessing in his trained hawk a known quantity with which to compare the performances of other birds.”
Captain Portal has flown hawks at many different kinds of birds during the last fifteen years, and has made certain estimates which have been arrived at after a great deal of comparison and analysis of data obtained while hawking, shooting, flying in aeroplanes, travelling in cars and trains, and walking in the country. He says:[10] “My figures cannot be correct for every member of each species, as I have seen one partridge in an October covey fly quite 15 per cent faster than any of its companions when all were at full speed. All I have tried to do is to strike an average for the species, the speed given being the maximum pace at which the bird can cover the ground in level flight through still air.”
The speeds given for the peregrine and merlin are those of good trained birds; the wild ones are faster. Here are the figures:
Golden Plover 70 miles per hour. Teal and Blackcock 68 ” ” Peregrine 62 ” ” Pheasant and Grouse 60 ” ” Mallard 58 ” ” Merlin and Blue Rock 55 ” ” Partridge 53 ” ” Green Plover } Jackdaw } 48 ” ” Wood Pigeon 45 ” ” Starling 44 ” ” Kestrel 43 ” ” Rook 40 ” ” Landrail 35 ” ”
The speed attained by golden plover when pressed has been estimated by airmen at over 60 miles per hour.[11]
Colonel R. Meinertzhagen, from whom I have also quoted above, states that he finds, “after eliminating abnormal conditions and observations based on meagre evidence, that the normal and migratory flight in miles per hour (ground speed) is as follows:
Ducks 44-59 Geese 42-55 Waders 34-51 (but mostly from 40 to 51) Starlings 38-49 Falcons 40-48 Corvidae 31-45 Tame Pigeons 30-36 The smaller Passeres 20-37”
Amongst the birds which are claimed by different high authorities to be the fastest British birds are the swift, the peregrine, the golden plover, the teal, the wild duck, and the curlew.
It is curious that in the various controversies on the subject no one appears to have contended that the golden eagle may possibly be the fastest flier amongst British birds. This may be because, except in certain parts of the country, the eagle is never seen, and there is necessarily very little opportunity of comparing his speed with that of other birds. In particular the falconer, whose opportunities of comparing the speed of birds are, as I have already stated, greater than those of any other class of men, has no opportunities in the case of the eagle. Moreover, the flight of the eagle, like that of some of the fastest flying birds, for instance, the blackcock, is very deceptive. He is in fact flying much faster than he appears to be--“The eagle’s flight, when passing from one point to another, is peculiarly expressive of strength and vigour. He wends his way with deliberate strong strokes of his powerful wing, every stroke apparently drawing him on a considerable distance, and in this manner advancing through the air as rapidly as the pigeon or any other bird which may appear to fly much more quickly.”[12]
The answer to the question, Which of the two birds, the eagle or the peregrine, is the faster flier, must even on a horizontal flight be a matter of pure conjecture. On the one hand, the peregrine has the advantage of pointed wings which make for increased wing power and speed, whilst the eagle’s wings are rounded. On the other hand, there is a great similarity between the general build and structure of the two birds, and there is the fact emphasised by Major Radclyffe in the letters from which I have quoted above, that, as between two birds of different size but of similar shape and make, the larger and heavier bird will almost invariably fly faster than the smaller and lighter one once the former really gets going. It is, of course, true that the peregrine is much quicker in its movements and more agile than the eagle. It is constantly under the necessity of flying at its fastest (which the eagle is not) in order to secure its food; in other words, to use the language of a stalker in discussing this question with me: “The peregrine requires a warm diet, and lives on its prey. The eagle, on the other hand, will eat carrion.” The peregrine is probably quicker off the mark than the eagle, but this does not necessarily mean that he flies more quickly than the eagle once the latter gets going. Stalkers have unusual opportunities of seeing these two birds in flight, and almost all those with whom I have discussed this question believe that on a horizontal flight the peregrine is faster than the eagle. This in my opinion is probably the correct view.
It must not be forgotten that the Northern falcons, or, as they are generally called, the gyrfalcons, are entitled to rank as British birds, although they are rare visitors to these Isles. They are (1) the gyrfalcon or Norwegian variety (_Falco gyrfalco_), (2) the Iceland falcon (_Falco islandus_), (3) the Greenland falcon (_Falco candicans_). The gyrfalcon is a very rare visitor here, two recorded specimens only having been obtained here and one of these is doubtful. The Iceland falcon is a rare visitor also, although identified examples have been obtained here from time to time. The Greenland falcon is an irregular winter and spring visitor, but there are more recorded instances of this species than in the case of the Iceland falcon. The former bird, the prevailing ground colour of which is white, is the most beautiful of all birds of prey. By some authorities it is considered merely a race of the Iceland falcon, which it resembles in size and habits. The eggs of the two birds resemble one another. All these Northern falcons are about the same size and larger than, though very similar in structure to, the peregrine falcon. Speaking generally, the difference in length is about 5 inches, in wing 2 inches. They have been very highly valued in Europe for hawking, and, as would be expected from their superior size and similar structure, are undoubtedly faster than peregrines.
Writing in the _Field_ for March 15, 1923, Major Radclyffe says:[13]
“All the gyrfalcons are much faster on the wing than peregrines, and having trained and flown both species of these falcons for many years I have been enabled to prove this beyond doubt.”
The swift has still to be considered. There are three species of swifts which rank as British birds: the common swift (_Cypselus apus_), the Alpine swift (_Cypselus melba_), and the spine-tailed or needle-tailed swift (_Acanthyllis caudacuta_ or _Chaetura caudacuta caudacuta_). The Alpine swift is a rare visitor here, only about thirty having been satisfactorily identified at different times from April to October in different parts of these islands, but chiefly in the southern part of England. It breeds in mountains throughout Central Europe, and eastwards to India. The spine-tailed swift is even a rarer visitor here, only two recorded instances of specimens having been obtained--one in Essex in 1846 and one (said to have been in company with another) in Hampshire in 1879. It breeds in the mountains of North-eastern Asia, and in winter goes as far south as Australia.
Swifts are perhaps the most powerfully winged, in proportion to their weight, of all British birds. Their form is that which has been found to make the fastest sailing vessel--full forwards and lengthened, and tapering backwards. The difficulty in regard to these birds, and particularly in regard to the Alpine swift and the spine-tailed swift, is to obtain the necessary opportunities and conditions for comparing their maximum speed with that of other very fast birds. It is difficult to realise merely from a consideration of the description and measurements of these three swifts in the authoritative works of ornithologists how much larger the Alpine swift and spine-tailed swift are than the common swift. I have had opportunities of handling and examining the stuffed specimens of these birds in the British Museum (Natural History) at South Kensington, and should like to acknowledge here the courtesy and assistance given to me at the Museum by Mr. W. P. Pycraft, Dr. P. R. Lowe, and Mr. N. B. Kinnear.
The actual measurements of the three birds are as follows:
Length. Wing. Common Swift 6·75 inches 6·8 inches Alpine Swift 8 ” 8·45 ” Needle-tailed Swift 8 ” 8·1 ”
It is not generally realised that the common swift, so well known in this country, which looks so imposing in flight as it glides overhead with wings extended, is hardly so large, when plucked, as a man’s thumb-joint and weighs slightly over half an ounce.
Bearing in mind that as between two birds of the same build and structure the larger will, when it gets going, fly faster than the smaller one, it would naturally be expected, as is the undoubted fact, that the Alpine swift and spine-tailed swift are faster fliers than the common swift.
The falconer has in the case of the swift very little opportunity of comparing its speed with that of the peregrine. This is partly because the peregrine, whether it be the falcon (the female bird) or the tiercel (the male bird), will probably not attempt to kill the swift, it being too small a prey. There is the further difficulty that the swift rarely continues on a level flight.
I have been so fortunate as to obtain the views of several well-known authorities on this difficult question--the comparative maximum speed of the swift and the peregrine.
Colonel Meinertzhagen says:
“I should certainly say that the swift is the fastest British bird, both in its normal speed and accelerated. But any of the falcons could catch it, if caught unawares, by stooping, or perhaps two hunting together. If the swift had, say, ten seconds’ warning,[14] I do not believe any falcon could touch it. As regards endurance, those birds with the greatest endurance are the swifts, swallows, petrels, and gulls. Swifts are probably endowed with the greatest powers, being denied by nature the advantages of perching, alighting on water, or resting on the ground. I have recently been studying the power of flight of various groups of birds, and find that the wings of the swift and petrel groups have wing outlines best suited for both endurance and speed. The falcon has a wing intended for short rapid flights and not for endurance.
“You have doubtless seen falcons hunting. When they set out on a regular hunt they are not usually much faster than their quarry, unless it is some unfortunate non-game bird, and they only gradually overtake it. But I think a falcon usually makes full use of surprise and force of gravity. If these fail, he often abandons the chase, recognising that wearing a bird like a golden plover or teal down by sheer endurance and honest straightforward flying is a troublesome and not always successful task.”
Major C. R. E. Radclyffe writes:
“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.
“It is very difficult to estimate the relative speed of different birds. To do so, one would have to judge correctly of the time taken in passing a measured distance on a straight course. Very few birds, especially swifts, fly absolutely straight ahead.
“A hobby has been known to catch swifts and swallows, and possibly a merlin would do the same.
“A peregrine can fly faster than a merlin, but it would not be so quick in turning and following a bird.
“I think a peregrine can fly faster than a teal or golden plover, though, as you observe, the latter are quicker off the mark.”
There are very few recorded instances, as far as I have been able to ascertain, in which a hawk has killed the common swift. In two of these there was no evidence as to whether the hawk had not taken the swift by surprise. But there is at least one recorded instance in which a swift has been killed by a hobby in fair flight. This is to be found in that delightful book, _Field Studies of some Rarer British Birds_,[15] by Mr. William Walpole Bond. The description of the race is so vivid that, with the author’s kind permission, I reproduce it here.
“On June 14, 1907, as I lay in a spacious clearing of a big Sussex woodland, a sudden swirl of wings gave me instant pause in my meditations. Looking up, my eyes were held by a swift coasting earthwards in frantic haste, hotly pursued by a hobby not many yards in his wake. I literally held my breath with excitement, for here was an occurrence of dreamland only. Speeding on about a level with the tree-tops both birds measure the length of the long glade in fractional time, and the hawk gains almost imperceptibly.
“Then the pursued makes a mighty effort; he rises gamely, even slightly increasing his lead. Indeed it seemed he might shake off his deadly courser. Alas, my friend, it is to no purpose; the hobby has responded to your challenge, and now exhibits speed for which--glorious flier though he be--I should never have given him credit. Mounting with ease above his prospective prey, the lithe hawk compels him to describe an arc and once again to start a life--or death--struggle in a headlong slant across the clearing. That flight is his last--the swift has shot his bolt. Now inches only separate the birds, you could cover both with a very large handkerchief. Next instant the hawk rises straight and stoops strongly, pursuer and pursued become one. Binding to his quarry the hawk is away over the trees at my back without so much as the most momentary pause in the continuation of his eminently successful ‘shikar.’ Indeed, this continuity of action was possibly the most pleasing part of a praiseworthy performance, since you might reasonably have expected a break--however trivial--after what must have been a long and arduous chase. As a fact, the death-stroke was so featly and rapidly administered that, except that where a moment before there had been two birds there was now only one, and that a muffled clap and a few small dusky feathers twirling aimlessly in the summer breeze suggested some sort of untoward happening, it was difficult to realise that anything unusual had taken place.
“I have seen the irresistible death-stoop of the peregrine, the lightning rush of the tiny merlin, I have watched the earthward plunge after prey of buzzard, eagle, kite, and harrier; I have revelled in the agile snatch of the sparrow-hawk, in the silent hovering of the kestrel; and all have I enjoyed. Here was something quite different and even far better. Never have I seen skill so superb as was displayed by that hobby.”
It would therefore seem that the hobby, which is a peregrine in miniature, flies faster than the common swift even on a horizontal flight, but it is worthy of note that in both stoops referred to in this delightful description, the hobby gained by reason of gravity. True, he also gained altitude, but this may have been better manœuvring for position and not necessarily a greater speed. As the peregrine flies faster than the hobby, being a bird of the same structure but larger, the peregrine could no doubt overtake and kill the common swift if it would take the trouble to pursue so small a bird.
Next, as to the Alpine swift. This bird is much larger than the common swift--in length 8 inches as compared with 6·75 inches--whilst their wings are 8·45 inches and 6·8 inches respectively, and as the two birds are of the same structure, one would naturally expect that the Alpine swift would be much the faster flier. The flight of the Alpine swift, like that of the blackcock, which is probably the fastest flier amongst game birds with the possible exception of the capercailzie, is very deceptive.
Colonel Meinertzhagen, in the article already mentioned, describes some observations from an aeroplane in regard to the flight of a large flock of common swifts feeding at an altitude of 6000 feet over Mosul in Mesopotamia. He describes how they circled round the aeroplane, which was flying at 68 miles an hour, and easily overtook it. In commenting on this case he says: “The case of the Mosul swifts is interesting. The birds were probably not on passage but simply feeding. It is known that swifts travel great distances in search of food and ascend great altitudes.
“In the Middle Atlas of Morocco, in the Himalayas, in Crete, and Palestine, 4000 or 5000 feet and 50 miles or so in distance seems nothing to these incomparable fliers. I have had splendid opportunities of observing the Alpine, common, and spine-tailed swifts (_Chaetura_), and it has been a great disappointment to me that I have never been able to get a satisfactory estimate of their rate of flight, as they never continue on a level course. On a small island on the coast of Crete I was recently given a good exhibition of what an Alpine swift can do. I was watching some of these birds feeding round cliffs in which several pairs of Eleonora’s falcons were about to breed. Now, this delightful falcon is no mean flier, and as these swifts passed their cliff, the falcons would come out against them like rockets. The swifts would accelerate and would seem to be out of sight before the falcons were well on their way. So confident were the swifts in their superior speed, that every time they circled round the island they never failed to ‘draw’ the falcons, and seemed to be playing with them. I may add that these same falcons have little difficulty in overhauling and striking a rock-pigeon--itself no mean performer. I have also seen on record the case of falcons and swifts somewhere in India, where the former failed time after time to come up with his quarry. I, unfortunately, cannot trace the reference.
“I hesitate even to guess at the speed to which a swift can attain when the necessity arises, but the main point is that this, the fastest of birds, can increase his feeding speed of, say, 70 miles per hour, to a velocity which must exceed 100 miles per hour.”
In the tables given above[16] Colonel Meinertzhagen estimates the speed of the normal and migratory rate of flight of falcons at 40 to 48 miles an hour, whilst Captain Portal estimates the maximum speed of the peregrine falcon in level flight through still air at 62 miles an hour. Captain Portal adds that the speed given is for a good trained bird, and that a wild bird is faster.
In view of Colonel Meinertzhagen’s observations from his aeroplane and the figures given above, it would appear to be certain that the Alpine swift is faster than the peregrine falcon in horizontal flight.
We have now to consider the speed of the spine-tailed or needle-tailed swift. There seems to be no doubt that this bird is a much faster flier than the Alpine swift, though at first sight and without a careful examination of the skeletons, it is difficult to state why this should be so. I have compared various specimens of the two birds, and there appears to be little difference in their size. Colonel Meinertzhagen, who has been so kind as to discuss the subject with me, agrees that the spine-tailed swift is the faster flier, and tells me that he thinks it is probably the heavier bird of the two, and that this may account for its greater rapidity of flight.
The wing of the Alpine swift is 8·45 inches, that of the spine-tailed swift is 8·1 inches. The length of both birds is 8 inches,[17] although Dresser[18] gives the total length as 8·5 and that of the spine-tailed swift as 8·1 inches.