102 The Field Naturalist' s Quarterly May 



deed, if you look down Professor Huxley's scheme of classi- 

 fication, which will probably form the basis of the system 

 of the future, you will see that the birds might have been 

 arranged in much the same order by their call-notes alone, 

 although Huxley's scheme is founded upon minute and 

 puzzling details of anatomy, with many exceptions to its 

 own rules. 



But the strongest proof of the value of the voices of birds 

 as a guide to classification is to be found in the fact that 

 such birds as the cuckoo, swift, nightjar, woodpecker, and 

 wren among British passerines are almost the only ones 

 which we could not confidently put in their places by their 

 voices alone, and that these are the very same birds which 

 present a puzzle to the scientific anatomists. The cause 

 of the difficulty is the same in both cases — namely, that 

 connecting links appear to be missing ; and I believe that 

 we are just as likely to discover these by study of their 

 language as by study of their bones. 



The foregoing paragraphs are to some extent quoted from 

 articles which I have previously written elsewhere in order 

 to illustrate the importance of a careful analysis of the 

 language of birds ; and I shall now explain the plan which 

 I hope that some readers will assist me to carry out. 



I propose to divide the language of birds as follows. 

 Taking the notes of the young first, we have (i) the call 

 for food. This appears to be habitually used only by 

 youngsters which can run, like chickens, or swim, like 

 ducklings, or whose safety is otherwise secured by nests in 

 inaccessible positions, as house-martins, or in holes, as 

 barn-owls and starlings. Young birds in open nests are 

 generally as silent as the dead. Thus at the very threshold 

 of investigation we reach a very interesting point. Next (2) 

 there is the young bird's note of anxiety. This seems to 

 be uttered by the young of all birds when they have been 

 separated long from their parents. In such cases in a state 

 of nature they would infallibly die unless their parents 

 discovered them, and therefore they raise a clamour. It 

 may attract enemies, but it is their only chance of escaping 

 death. The note of fear (3) is only used apparently by those 

 young birds whose parents are strong and courageous. A 



