COURTSHIP AMONG BIRDS 129 



if unmusical serenade ; with outstretched neck, drooping 

 wings and spreading tail he gives forth a weird, uncouth 

 kind of song, more or less divisible into three parts. He 

 begins with a series of notes v^^hich remind one of nothing 

 so much as the sound made by two sticks knocked 

 together at intervals of ten to fifteen seconds, getting 

 quicker and quicker, and changing in key till at last 

 they become bell-like. Then follows a series of sounds 

 like the drawing of a cork out of a bottle, and these end 

 with, bird-like twitterings. By this time, however, the 

 singer has worked himself up to an ecstasy of fervour and 

 passion so intense as to deaden him to all that may be 

 passing in the outer world. During these moments no 

 sound disturbs him, partly, apparently, because the 

 excitement of the " song '* causes a turgid condition of 

 the blood-vessels which for the time effectually deafens 

 him. " Sportsmen," in Swedish and other European 

 forests, knowing this, select such performances as affording 

 the most favourable time for Capercaillie shooting, only 

 cocks being selected. 



A survey must now be made of some of the more 

 remarkable cases whereby more or less m.usical, or 

 rhythmical, sounds are made by instruments of percus- 

 sion; or by rapid vibrations. These are in almost every 

 instance formed by varying grades of modification in 

 the feathers of the wings or tail. Their presence, and 

 their use, seem natural enough until we recall the fact 

 that many other birds without any apparatus whatever, 

 make sounds in no way less remarkable or less penetrating. 

 Pigeons, Nightjars and Owls, for example, can produce 

 at will curious snapping sounds by bringing the wings 

 smartly together over the back. The White, and Shoe- 

 billed Storks make castanets of the beak, throwing the 



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