2IO BiCKNELL on the Singing of Birds. [J"ly 



Mniotilta varia. Black-and-white Creeping Warbler. 



With this species, singing continues from its arrival in late 

 April until the end of June. In some years I have not heard its 

 song at all in July ; in other years it sings occasionally up to the 

 end of that month. The second song-period begins about the 

 middle of August (9th to 32nd) , and may last for a fev^ days only, 

 or for over tw^o w^eeks ; concluding dates fall between August 18 

 and 28. An exceptional date for song is September 23, 1879, 

 when one of these birds was heard to sing perfectly several suc- 

 cessive times. Final departure occurs five or six weeks after the 

 cessation of song. 



Helminthotherus vermivorus. Worm-eating Warbler. 



Commonly remains in song after its arrival until the second 

 week of July. Sometimes singing ceases a little earlier than this ; 

 again, in other years, songs are to be heard into the third week 

 of the month. 



The second song-period of this Warbler I can speak of only 

 from one season's experience. On July 10, 1881, several of these 

 birds were silently inhabiting a small tract of woodland, their 

 first season of song having passed ; here, on August 14, and again 

 on the 21 st, they were found in fine plumage and in full song. 



The songs of no other three birds known to me are more alike 

 than those of the Worm-eating Warbler, the Chipping Sparrow, 

 and the Slate-colored Snowbird. 



Helminthophila pinus (Z.) Ridgw. Blue -winged Yellow 



Warbler. 



My data relating to the ending of the first song-period, in the 

 case of those of our summer birds which earliest become silent, 

 are less complete than I could wish ; for experience had to teach 

 me that observation which would discover the time when several 

 species left off' singing must begin before the middle of June. 



The Blue-winged Yellow Warbler is perhaps the first of our 

 summer birds to withdraw from the feathered choir. After its 

 arrival in early May, scarcely a month elapses before singing has 

 begun to wane ; and it is not often continued after the middle of 



