The Singing of Birds. E.P.Bicknell. 
Coturniculus passerinus. Yellow-winged Sparrow. 
This little field bird continues in song up to the middle of July 
or later, sometimes even into the early days of August. It seems 
most persistent in song in hot, dry summers, when, on the most 
fervid days, its fine notes sound sibilant and insect-like about the 
parched fields. Auk, I, Oot. , 1884. p. 33 0 . 
