1 64 The Irish Naturalist, ' June, 



the courage equal, a battle follows." I need scarcely add that 

 bird-catchers take advantage of this fact to catch male birds 

 in spring; and it is by pla5dng upon the same propensity 

 that boys in the country decoy the male Corncrake from his 

 cover, by imitating his " crake" with a stick drawn across a 

 comb. That it is the male, not the female, Corncrake who is 

 thus decoyed, is shown by the fact of its craking in reply to 

 the challenge, up to the very moment of leaving cover. 



The chief and primary use of song, then, as I conceive it, is 

 to advertise the presence in a certain area of an unvanquished 

 cock-bird, who claims that area as his, and will allow no other 

 cock-bird to enter it without a battle. ;::..;-, 



The question may be asked, is not bird-song too elaborate 

 to be thus accounted for? Would not simpler notes answer 

 the purpose equally well? I think it may be shown that the 

 more elaborate singers do, however, obtain an advantage in 

 this manner. Since oxAy the unvanquished bird has an area 

 to sing in, the vanquished birds must, after their defeat, 

 observe silence, while the conqueror, secure in his holding, 

 sings triumphantly on and on, his voice and his powers of 

 expression naturally improving by practice, and thus pro- 

 claiming to all who come within the charmed circle of his 

 audience what a lot of practice he has had. Thus, all over the 

 country, the finest singers are known from their superior vocal 

 power to be those with the longest record of success in life, 

 and the poorer singers are naturally afraid to start competition 

 with them. This, of course, renders their tenure of power 

 more secure than ever. 



And, in the matter of plumage, although it has been 

 shown by careful accumulation of evidence that birds of 

 polygamous character — and even some monogamous species — 

 behave very much as if the female had a taste for the beauti- 

 ful ; and it seems unreasonable to doubt that the bright tints 

 acquired by the more richly ornamented males are agreeable 

 to her eye, it does not follow that that is their primary value. 

 Darwin, in summarizing his evidence on this subject, makes 

 the interesting statement on Mr. Jenner Weir's authority that 

 ** all male birds with rich or strongly characterised plumage 

 are more quarrelsome than the dull coloured species belong- 

 ing to the same groups." Have we not here some ground 



