THE ZOOLOGIST. 



THIRD SERIES. 



Vol. XIV.] JULY, 1890. [No. J63. 



THE EVOLUTION OF BIRD-SONU. 

 By Charles A. Witchell. 



For some years I have studied the voices of British wild 

 birds, and in pursuing my investigations have become acquainted 

 with several interesting facts which seem to indicate how bird- 

 song has been evolved. As the notes collected relate to the songs 

 of several hundreds of individual birds, it is impossible in these 

 pages to give more than a general summary, together with the 

 conclusions arrived at. Any more elaborate analysis must be 

 deferred to a future occasion. 



In the arrangement of these notes I have received much aid 

 from Prof. Harker, F.L.S., and Mr. S. S. Buckman, F.G.S., has 

 suggested several useful alterations in the MS. 



All birds possess the power to emit a cry of distress — that is, 

 an exclamation caused by bodily pain, or by fear, and this cry 

 seems to be the first utterance of the young of most species. It 

 is presumed that a cry of distress was the earliest vocal utterance 

 within the ability of the bird or its progenitors ; and it may have 

 been originally produced accidentally by contortion of the body 

 during combat, in which event it might have tended towards the 

 preservation of the individuals by which it was uttered. If an 

 outcry increased the chance of victory in combat, the inclination 

 and ability to exclaim would become permanent, and the cry 

 would be habitually uttered in the tone most easily produced, or 

 most effectual in its result. It would thus become a definitely 

 formed cry, and would soon be uttered in circumstances of danger 



ZOOLOGIST. JULY, 18 ( d0. T 



