AVES 277 



sweetheart, "lifts his wings, spreads his tail, and begins to nod 

 right and left as he exhibits his moustache to his cliarmer and 

 sets his jet locket first on one side of the twig and then on the 

 other, and she plays back at him in a similar peek-a-boo fashion." 

 The drumming of the grouse and the bill tattoo of the woodpecker 

 are efforts to charm. Odor has no part to- play in the art of 

 pleasing among birds, for the musk duck is said to he the only 

 bird which secretes an especially odorous substance. 



Battle among birds may be for self-defense or for defense of 

 young, but it is most commonly for rivalry, as both Wallace and 

 Darwin believe. For bird battles there are various kinds of 

 weapons. The cassowary has the elongated inner toe armed 

 with a long straight claw and the short wing quills modified into 

 spines. During the nesting season many males have wing spurs 

 which subside into something like knobs when the season for their 

 use is over. Unlike the bony wing-spur, the leg-spur is devel- 

 oped from the skin. Some birds fight fiercely, while others merely 

 run a bluff by some terrifying attitude, wherein they display 

 their wing-spurs. 



Song. — There is much reason to think that the song of the 

 male bird is a means of pleasing or courting the favor of his 

 wished-for mate, though he afterward sings to cheer her during 

 the period of incubation. The song often ceases when the 

 young are hatched; there is something else to be done then. 

 But the song is heard again during the preparation for the 

 second brood. 



There are many call-notes for other purposes than rivalry. 

 Chapman says that "call-notes form the language of every day 

 life, while song is the outburst of special emotion." The call 

 of the mother to her young in warning, in fear, in reassurance 

 when danger is over, the cry of hunger or distress in the young, 

 the thankful little chirp when feeding or when cuddling under the 

 mother's wing, the scolding of both parent birds when an enemy 

 approaches the nest; all these and others have their significance 

 in bird language. One would find this study far more interesting 

 than that of a dead language and the opportunity for its 

 pursuance is present everywhere. Try to imitate the vari- 

 ous call-notes of the birds with which you are familiar and make 

 a list. 



