Voi.^XXJ BB.E.\\iiTV.R, Notes on t/ic P/iiladclf'/tia I'l'rco. 37 J 



grayish brown color. Holding my glass on it with some difficulty 

 — -for I was now actually trembling with excitement — I made it 

 out clearly to be a small, neatly-finished and perfectly new-looking 

 Vireo's nest attached to a short lateral twig of one of the long, 

 upright terminal shoots that formed the crown of the aspen. 

 Looking still more closely I could see the head of the sitting bird 

 and even trace the swelling of his throat and the slight opening of 

 his bill as he uttered his disconnected notes. Soon after this he 

 left the nest and flying to a neighboring tree alighted on a dead 

 twig w'here I had a clear view of him and quickly satisfied myself 

 that without question he was a Philadelphia Vireo. He looked no 

 larger than a Nashville Warbler, and his breast, when he turned 

 it towards the sun, appeared bright yellow, while his throat was 

 unmistakably — if less strongly — tinged with the same color. It 

 was fortunate that I was able to thus positively identify him by 

 sight at this particular time. Had I not done so I should have 

 continued my walk without troubling myself further about either 

 him or his nest, for the song which he now began — and con- 

 tinued, with occasional brief pauses, for upwards of ten minutes 

 — was to my ears absolutely indistinguishable from the typical song 

 of Vireo olivaceus. The voice appeared to be the same in pitch 

 as well as quality, the notes similar in both form and expression, 

 and the delivery equally rapid. I regret that it did not occur to 

 me to time the number of separate utterances per minute, but I 

 feel sure that there must have been as many as the most voluble 

 ' Preacher ' often succeeds in producing. Dr. Dwight says that 

 " V. philadelphicus sings at the rate of from twenty-two to thirt}^- 

 six notes a minute, averaging a trifle over twenty-six, while V. 

 olii'aceus rattles on at the rate of from fifty to seventy, their song 

 rate averaging a trifle over fifty-nine." This, no doubt, is ordi- 

 narily true, but equally without question the rule just quoted is 

 not always adhered to by either species — as, indeed. Dr. Dwight 

 seems to have known, or at least suspected. His comparative 

 description of the songs of the two birds is so good and true at 

 most points that, as a whole, it is not likely to be ever improved 

 upon. Nevertheless by reason of its very depth and subtilty of 

 analysis it tends to obscure what is really the crux of the whole 

 matter, viz., the fact that the differences with which it deals so 



