Snipe 'drumming' 77 



the sound at all exactly, it is necessary to impart with the arm a shi\-er- 

 ing motion to the stick, as it is carried downwards tlnough the air. 



Stevenson, writing from personal observation, points out that 

 snipe drum at times " with ilie least possible fall," and often a very 

 considerable fall occurred without any drumming. The former of 

 these statements is a strong point against the " pure tailers " : 

 the feather on the stick must be driven with great velocit\- through 

 the air in order to produce the sound at all — certainly a greater 

 velocit\- than the snipe makes use of in an average downward stoop. 

 The drumming with very little fall, almost forces one to the conclusion 

 that the noise is being produced by some other agency than the tail 

 feathers alone. 



The Snipe is not frying downwards : he is making no use of 

 his wings as a means of direct downward progression, but is simply 

 pitching groundwards by the force of gravity, maintaining a certain 

 angle and a certain curve with the earth by means of the set of his 

 tail and wings. 



To produce the drumming, even a minimum of sound, from 

 the mounted feather, you must drive it through the air at a much 

 greater rate than the Snipe ever uses, or indeed is able to use, 

 in his downward pitch, and, when all is said and done, you produce 

 a sound infinitely less resonant than the natural drumming which 

 can be heard at ten times the distance. 



Both Hancock and Harting point out that other birds besides 

 Snipe make a vibratory sound of an analogous character, especially 

 instancing the Lapwing in the breeding season. 



In this case of this latter bird, it is certain that the noise 

 is produced bj' wings, and wings alone. The tail feathers are closed, 

 and the two outer feathers are entirely unlike the " sonorous " 

 feathers of the Snipe, and quite unfitted to produce any sound at all. 



Finally, Hancock* refers to the distance at which the soimd can 

 be heard, and asks whether it is conceivable that the vibration of 

 two small tail feathers can produce a sound audible at half-a-mile or 

 more, when the bird itself is out of sight. 



The volume of sound alone would seem to him sufficient ground 

 for negativing the " pure tail " theory. 



3. Like the tail theory, the " pure wing " theory is exceedingly 

 hard to disprove. 



I belie\-e myself that the wings are part-producers of the sound — 

 the main agents if you choose — but there are more arguments than 

 one against their being the sole originators of the sound. 



While it is true that some other birds do make noises with their 

 wings of a somewhat analogous character, in none of these is the 

 sound produced exactly similar to the drumming of the Snipe : 

 and the number of birds instanced, which do make any such sound, 

 is comparatively small ; whereas, one might expect, if wings were 



* " Birds 01' Northumberland and Durham," vi., pp. 105-113. 



