Some little time ago, a correspondence appeared in the Observer[4] and the Field[5] as to which is the quickest bird in flight. Various correspondents, some of them well-known naturalists, writers of repute, and sportsmen of experience, expressed their views, by no means unanimous, on the question. I have always been greatly interested in the subject, and for many years past in the North of Scotland have been in the habit of watching bird life in some of the wildest and most inaccessible parts of the country.
I have examined the evidence contained in the valuable and interesting correspondence mentioned above, and have also obtained all the information I could get elsewhere from books of authority and persons who have had special opportunities of observation. At the present day a valuable and novel class of evidence is available—that of observers in aeroplanes. Upon all the material thus obtained I have tried to form an impartial opinion.
There appear to me to be four points to be borne in mind before arriving at any conclusion as to which bird is the quickest in flight, and the maximum speed of which each bird is capable.
Emphasis is laid on the first three of the following points in some of the letters in the correspondence above referred to, but I think that the fourth point is of at least equal importance.
1. Ground speed must be distinguished from air speed.
2.The path of flight must be horizontal.
3.There must be something to show that the bird is flying at its maximum speed.
4.There must be a standard length of flight to which the test is to be applied.