1^2 Bickxf.ll on the Singing- of Birds. [April 



The song-flight of the Indigo-bird I have but once witnessed 

 — on September 23, 1S79. 



Regarding the singing of the Indigo-bird, Mr. Fred. T. Jencks, 

 of Providence, writes me that he is able to distinguish by their 

 songs the younger from the full}' adult birds at a distance of at 

 least one hundred and fifty yards. The songs of younger birds 

 are more simple and less musical than those of adults. 1 am 

 myself familiar with differences in the songs of Indigo-birds such 

 as Mr. Jencks describes, but never traced them to their cause. 



Dolichonyx oryzivorus. Bobolink. 



During its half-year visit the Bobolink sings only in May, June 

 and part of July. Through the remainder of its stay, it has only 

 a single short note. This is of a softly metallic tone, and in 

 late summer and early fall is showered down over the country, 

 and sometimes over the city, and at night, by flocks of the birds 

 passing on their southward way. It is also a characteristic bird- 

 note of the late summer, about wide weedy meadows, where tall 

 Composite and other ranklv growing plants uphold a rich 

 harvest of seeds. 



The song of the Bobolink is one of the first to drop out of the 

 bird-chorus. I have not often heard it in July, and never later 

 than the middle of the month ; though where the bird is more 

 common in the breeding season than with me singing doubtless 

 continues later. 



Molothrus pecoris. Cowbird. 



The song-utterance of this species, although giving a slight 

 reminder of its near relationship to the Blackbirds, is neverthe- 

 less strikingly unique. It has an indefinite beginning, which 

 is continued into a high attenuated note, ending with a sound 

 curiouslv like that of bubbling water. This irresistibly suggests 

 a bubble-like bursting forth of sound after a long audible inhala- 

 tion. It seems to be a sort of appendage to the ordinary song- 

 notes, and is, perhaps, achieved only by vigorous individuals,- or 

 under the stimulus of courtship. Its production appears to be a 

 matter of some difficulty, being attended by singular bodily con- 

 tortions and a spreading and stiffening of the wings and tail- 



