INDIGO BUNTING 97 



shortened. The light intensity vakies in foot-candles for the first 

 daybreak song change from 0.014 in May to 0.022 in June to 0.74 in 

 July. Mean light intensities in foot-candles for the evening song 

 change from 0.51 in May to 1.00 in June to 8.92 in July. 



Charles Vaurie (1946) kept records of an individual for 47 consecu- 

 tive days, July 20 to September 4, 1944, on the lower slopes of a 1,000- 

 foot hill in the foothills of the Blue Mountains in Berks County, 

 Pa. The bird was in continuous full song with only normal intervals 

 until August 3, then sang noticeably but with fairly long pauses until 

 August 20. The bird ceased singing during a 6-day cold spell, then 

 continued singing on a much reduced scale. On September 4 one 

 particular bird out of more than two dozen was singing as at the start, 

 in continuous full song. Vaurie considers that it "is sometimes tire- 

 some to hear this bird sing because it can go on for hours without 

 stopping, while the song grows harsher and harsher and begins to slur 

 and break." 



Val Nolan, Jr. (1958) watched a female near Bloomington, Ind. 

 "This female, a bird with no blue visible in her plumage, sang during 

 two brief intervals on May 29, 1956, a cloudy day with temperatures 

 of 66° and 76° at the times of singing. At 0501 central standard time 

 she mounted to the top of a 15-foot Virginia pine, the highest perch 

 within 20 yards in scrubby old-field growth. During the next 2 or 3 

 minutes she sang 10 loud songs, described below, then moved a few 

 yards and sang 10 more from a spot out of my sight. Between 0911 

 and 0921 she sang six times from the same general location, but again 

 I could not see her. There was no repetition of the song during the rest 

 of the day * * * ; nor did I hear the song here on four other dawn-to- 

 dark watches and many briefer ones between May 17 and Jime 8. 



"The songs, which were wholly immusical, consisted of five similar 

 windy, vibrant notes uttered in staccato fashion and seeming to my 

 inadequate ear to rise in pitch from first to last. I was reminded of 

 the abrupt, choppy song of the dickcissel and could not have identified 

 the singer's species by her voice. 



"A male indigo bunting was on territory in the field, and though he 

 sang and was in view repeatedly throughout May 29, I neither saw 

 nor heard him while the female was singing. A female was found 

 incubating on this territory some 2 weeks later." 



In spite of this detailed account it seems possible to us that Nolan's 

 "female" was in fact a male. The individual was not taken, and it 

 could have been a brown first-year male or an older bird that had not 

 molted fully. 



G. M. Sutton (MS.) states that the flight song may last eight 

 seconds or more and is given principally during the morning and eve- 

 ning twilights, although occasionally in full dayhght. It possesses 



