528 BULLETIN 2 3, UNITED STATES NATIONAL MUSEUM 



food of two that he examined. The bird is doubtless mainly insec- 

 tivorous and probably obtains most of its food on, or near the ground. 

 An interesting item of food is mentioned in Dr. Skutch's account of 

 winter habits. 



Behavior. — In a general way the behavior of the mourning warbler 

 is much like that of the northern yellowthroat, though it is rather 

 more timid and retiring, plunging into the densest thickets on the 

 slightest alarm. It is especially secretive on the fall migration, skulk- 

 ing through the thickest underbrush on the edges of the woods or 

 along old brush fences. But, in the spring, the males are often quite 

 conspicuous, mounting to the tops of bushes or small trees to sing. 

 William Brewster (1938) writes: "A male among fallen tree-tops 

 behind the house eluded me in the most provoking manner, creeping 

 about like a Wren among the debris. Sometimes he would appear 

 within a few yards of me, disappearing almost instantly, and when 

 next seen would be perhaps forty or fifty yards away. His gait was 

 distinctly a 'hop' but in other respects he resembled the Connecticut 

 Warbler, especially in flight and in attitude when perched." 



Voice. — Aretas A. Saunders contributes the following study of the 

 song : 



"The song of the mourning warbler is quite short, and averages a 

 little lower in pitch than most warbler songs. It is loud, musical in 

 quality and contains marked explosive and liquid consonant sounds. 

 It is usually in two distinct parts. 



"The first part consists of 2 to 5 notes, slurs, or 2-note phrases, 

 sounding, when a single note, like tleet or tseet^ and when of 2-notes 

 like tolee or choree, varying in individual birds. The majority of songs 

 have 3 such notes or slurs. Of my 30 records 20 slur upward, 6 slur 

 downward, and 4 are single notes. When they slur downward the 

 sound is like teelo. The second part is short, and the notes faster, 

 especially when there are many. The number of notes varies from 

 1 to 9, averaging 3. In 5 records there is no second part. The notes 

 of the second part vary considerabl}^ In some songs they are all 

 equal and on one pitch, sounding like to to to or tsit tsit. When there 

 are more notes they vary in pitch and are often connected giving an 

 effect like totletoleeto. The second part is two to three tones lower in 

 pitch than the first. 



"The pitch varies from C" to W\ a half tone less than an octave. 

 Individual songs range from one to three and a half tones, averaging 

 two tones. Songs are from 1 to 2 seconds in length. The notes of the 

 first part occur about three a second ; those of the second part about 

 \\Y& a second. 



"The mourning warbler also sings a flight song which is somewhat 

 longer, ccaitains several choree notes, usually at the begimiing, and 



