°,S97 j DwiGHT, The PJiiladelpJiia Vireo. 267 



syllables when heard close at hand and the inflection rises slightly 

 on the latter. A pause follows, approximating one and two fifths 

 seconds, and the first note is again repeated, less forcibly and 

 sUghtly varied. Again the pause ensues, and now it is followed 

 by a triple note, not interrogatory and indistinguishable from one 

 of V. olivaceus. Again the pause, this time followed by a repeti- 

 tion of the triple note, slightly varied so as to lose some of its 

 sibilance, and after the customary pause of one and two fifths 

 seconds, the song is repeated from the beginning, nearly eight 

 seconds having elapsed in completing one cycle. The four notes 

 may be suggested by the syllables chur-r\ve, chur-w'e, pst'-i-re, 

 psr'-?--re. The sequence of the notes, however, may vary a little, 

 owing to the occasional substitution of one for the other, but the 

 same one is not repeated more than twice in succession, even after 

 a break in the continuity of the song. Heard at a distance, it 

 practically reduces to two alternated notes, which I find repre- 

 sented in my note books of different years as chnr-unp, tur-\-d\p 

 in one place ^w^ ps't-iviC rt, psl-wu-fit in another. The discrepan- 

 cies are instructive, showing independent efforts on my part 

 to lay hold of the same sound. 



The speed at which the song flows on is an interesting factor 



and is remarkably uniform for each individual songster, in fact, 



I could almost identify certain Philadelphias and Red-eyes by 

 timing their songs. V. philadclphicus sings at the rate of from 

 twenty-two to thirty-six notes a minute, averaging a trifle over 

 twenty-six, while V. olivaceus rattles on at the rate of from fifty to 

 seventy, their song rate averaging a trifle over fifty-nine. I do 

 not mean to assert that there were always just so many notes in a 

 given minute, for both species pause irregularly and drop out 

 notes now and then, but if all were uttered in the same cadence 

 as those actually heard, these figures would be equaled, and, in 

 fact, very often are equaled. They are, however, only to be 

 satisfactorily obtained at the height of the song period, and but 

 for the careful use of a stop-watch I would hardly feel justified 

 in presenting them. Some individuals are better songsters than 

 others, but all follow more or less closely the type I have 

 endeavored to describe. The song is sometimes a softer and 

 disjointed affair and this soliloquizing type is characteristic of 

 the wane of the song period. 



