1907.] " bleating" OF THE SNIPE. 15 



In answer to this paper, von Zoppritz (Ornith. Central blatt, 

 Nov. 1880) disputes Altum's tail-theory, giving four reasons, 

 which I will not here quote*. 



III. The wing-theory has had the greatest number of adherents. 

 Macgillivray in 1840 (' British Birds,' vol. iv. p. 372) expresses 



his conviction that this is the case. Sir Wm. Jardine, in the 

 'Naturalist's Library ' (vol. xxvi. Ornithology, p. 180), says: "The 

 sound is never heard, except in the downward flight, and when 

 the wings are in rapid and quivering motion. Their resistance 

 to the air without doubt causes the noise. Dr. Saxby (' Birds of 

 Shetland,' p. 204) expresses his conviction that ' drumming is 

 produced by the vibrations of the wings alone.' " 



Naumann, in the article already quoted, and Zoppritz (Ornith. 

 Oentralblatt, Nov. 1880) wrote in favour of it in Germany. 



John Hancock, whom I have ah^eady quoted, agrees in the 

 main with what Mr. J. E. Harting(' Essays on Sport and Natural 

 History,' pp. 284 et seq.) has written : — " From the peculiar 

 vibration of the wings in the downward descent of the bird, it 

 would appear that the primaries, instead of firmly overlapping 

 each other, are, in the act of humming, turned broadside in the 

 air, which is thus able to play across the inner web of each, and so 

 to impart to each a vibratory motion and consequent sound — faint 

 indeed in the case of a single feather, but audible enough when 

 an entire wing is acted upon. Whether this be the true expla- 

 nation of the singular sound, it is, of course, not easy to prove 

 conclusively ; but it has certainly been accepted as svich by many 

 naturaHsts in England, who are the more inclined to adopt this 

 view from having observed Peewits, Rooks. Gulls, and other birds, 

 with tails very difterent from that of a Snipe, make an analogous 

 sound while falling through the air." That Mr. Harting was 

 partially successful in producing the bleat artificially is evident, for 

 he has " succeeded beyond expectation in producing a sound like 

 the ' humming' of the Snipe." Again : " But any of the primary 

 wing-feathers will give forth a faint sound, which may be increased 

 in proportion to the number of them passed through the air at 

 once." But he finds that the tail-feathers when fastened into a 

 switch do not occupy the position they do naturally in the bird's 

 tail, because they are drawn through the air at light angles to the 

 direction of flight, "in a position which is occupied naturally by 

 the primaries, but unnaturally by the tail, and hence it must be 

 the primaries (collectively) which produce the sound in nature. 

 In this our sense of hearing is assisted by the sense of sight, for 

 a perceptible vibration of the quill-feathers is observed every time 

 the bird descends." 



IV. Two observers maintain that the sound is prodviced by 

 the agency of both the wing- and tail-feathers. 



H. Gadumer (' Naumannia,' 1853, pp. 411-413) watched a bird 



* [Mr. P. W. Headley (' Nature', vol. Ixx. p. 103, 1904) supported the theory that 

 the drumming was pi-oduced by the outermost tail-feathers, and adduced an expe- 

 riment by which the sound could be produced artificially.] — Ed. P. Z. S. 



