BLACK-BILLED CUCKOO. 



Biaok-biiied The Black-billed Cuckoo is distinctly a 



more musical bird, although his song em- 

 Coccyzus ery- . . .. , , 



throphthalmus Draces but two well-defined tones only one 

 L. 11.75 inches of which is commonly prominent. In 

 May isth appearance he resembles the foregoing 



species, with a few minor differences. Upper parts 

 brown-gray with a greenish iridescence ; the tail feath- 

 ers not black and only narrowly tipped with white; 

 under parts dull white ; bill entirely black. The nest is 

 similar to that of the preceding species, but the egg is a 

 deeper tone of green-blue. This bird is also a wholesale 

 destroyer of the tent caterpillar ; he is distributed farther 

 north than the preceding species. 



The most distinct feature of this Cuckoo's song is the 

 rhythmic recurrence of the rest. This is a thing as 

 easily recognized by the unmusical as the musical lis- 

 tener. When one hears a series of rhythmically inter- 

 rupted monotones coming up from the meadow, there 

 can be no doubt about the singer, it is the Black-bill I 

 No other bird sings exactly that way. I can perfectly 

 demonstrate the principle by a series of dots to repre- 

 sent the notes, thus : But the 



bird does not always stick to couplets, 



nor does he particularly favor triplets, 



nor is he unmindful of the fact that even in music " va- 

 riety is the very spice of life " 



It is apparent, then, that however irregular the number 

 of the notes, the principle of rhythmic pause remains 

 irrefragable. So perfectly timed is this pause, that upon 



COU'COO, COU-COO, COU-CU-COOj COU'CO^CQU-CU'OOQ.COU-CU'COO. 



setting the metronome to the song the bird will be 

 found singing with almost mechanical accuracy. There 

 is also another well-marked feature of the Cuckoo's song. 

 Listen attentively to the quality of a single tone and it 

 will at once become apparent that it is accompanied by 

 an undertone (properly an overtone) of a more or less 



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