CHAPTER X 



Song and cries of birds Bird-language generally Extent to 

 which the notes are instinctively developed The instinct of 

 mimicry Species which can imitate human speech Problem 

 of this ability and extent of exercise of the same Possibility 

 of understanding of bird-language by man. 



FROM the earliest historical times the voices of birds 

 have attracted at least as much attention as their 

 flight and plumage, as is natural, for they are the 

 most vocal of all animals, voice being more charac- 

 teristic of them than flight, for there are a good 

 number of flightless species, as we have seen, while 

 none are destitute of voice at all ages and in both 

 sexes ; for even among the typical Storks, which 

 have evolved a sort of deaf-and-dumb language by 

 clattering the bill, the nestlings utter wheezing 

 squeaks, and although some of the males of the 

 Ducks are nearly voiceless, such as the Muscovy 

 drake, which only utters a wheezing sound as if 

 panting for breath, the females always have a distinct 

 loud note, though in the case of the Muscovy Duck 

 this is rarely uttered. 



The curious bulb found at the base of the wind- 

 pipe in so many of the males of the Duck tribe 



seems to act as a damper to the quack of the drake ; 



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