EASTERN OVENBIRD 467 



single notes and end with 2-note phrases, while one begins with 2-note 

 phrases and ends w^ith single notes. 



"The pitch ranges one octave, from C sharp '" to C sharp "" . One 

 bird whose song I recorded sang two different songs, the lower one 

 reaching C sharp '" and the higher C sharp "". The song lasted from 

 1% to 314 seconds. There is some variation between individuals in 

 the rapidity of singing, some singing about three 2-note phrases per 

 second and others about four. The accented note in the phrases may 

 be either higher or lower in pitch than the unaccented, and my records 

 are about equaly divided in this matter." 



Albert R. Brand (1936) has analyzed the songs of birds, including 

 the ovenbird, through a detailed study of film recordings. He writes : 



The speed of bird song was found to be extremely rapid. Many songs that 

 seemed to consist of only a few notes actually contain four or five times as many 

 as the ear can detect, and, in several cases, songs that are assumed to be^ 

 divided — that is they seem to be made up of several notes — under the micro- 

 scope were found to be continuous — only one note. 



Such was the case of the oven-bird film studied. This song certainly sounds 

 to me, and I imagine to others, as if it consists of a number of separate notes, 

 if not phrases. It is often written, teacher, teacher, teacher, TEACHER, 

 each "teacher" representing one phase or group of notes. But on the film the 

 story is different. The film tells us that this song, which to our ear seems- 

 to be made up of a number of phrases, each of which in turn consists of one note 

 that is changing constantly in pitch, is really a continuous note. However, the 

 pitch is constantly changing; on that point the ear is correct. * * * The 

 change after the downward movement of the note (flatting) into the higher 

 portion of the song probably causes one to assume that the song is a series of 

 notes, which it certainly is not. Many notes in bird-song were found to be of 

 incredibly short duration, sometimes as short as a hundredth of a second, and 

 the pauses between the notes are even shorter, occasionally only a fraction of 

 that time. It is physically impossible for the ear to distinguish such short notes 

 and intervals ; it is no wonder that until the microscopic film studies were made 

 these very short notes had not even been suspected. 



In his study of vibration frequencies of passerine bird songs Brand 

 (1938) found that the vibrations per second of the highest note of the 

 ovenbird was 5,850, the lowest 3,300, and the approximate mean about 

 4,000. 



Apparently this song is not peculiar to the male, for Robert W. 

 Hiatt (1943) states that he collected an ovenbird, that was singing as 

 it walked among fallen leaves and branches, which proved to be a 

 female. Whether it is of common occurrence for the female ovenbird 

 to sing is not known, since the sex is difficult to determine without 

 dissection. Better to leave such an academic question unsolved than 

 to collect singing ovenbirds solely for such a purpose! 



In addition to the ordinary song, the ovenbird has another song, 

 much more musical and beautiful, generally sung during flight and 

 frequently referred to as the flight song. It is not heard until about 



