EVOLUTION OF BIRD-SONG 



14. Flight in song. It seems to me that flight 

 is not resorted to during song merely to enable the 

 singer to utter his notes from an elevation, but that 

 in several instances the manner of the flight itself is 

 intended to suggest to a female bird the attention of 

 a suitor ; and that when so employed it is to some 

 extent analogous to that flapping of the wings 

 which gives expression to the wants of many young 

 birds when about to be fed. 



The greenfinch sometimes exhibits, perhaps, the 

 most characteristic flight when singing, its wings 

 being fanned slowly, and with their widest sweep. 

 The sedge- warbler sometimes behaves in a similar 

 manner. The wood-warbler flies in song with the 

 same stroke of wing, as I have seen it, at the 

 distance of eight or ten feet. Individuals differ in 

 the extent to which this habit is followed. One at 

 Leigh woods flew during twenty-seven out of thirty 

 repetitions of the sibilous phrase. The legs of the 

 wood-warbler are extended during this performance, 

 like those of a rook just after it leaves the ground ; 

 in the former bird this attitude probably permits of 

 a slower flight, just as in the latter it undoubtedly 

 favours the execution of a more vertical ascent. I 

 have seen a blackbird dart from his perch, in the 

 middle of a phrase, and gesticulate while singing 



