WARBLERS. 119 



their heads, instantly returning, and now flutter before a cluster 

 of opening leaves, with the grace of a Hummingbird. Occa- 

 sionally they descend to the ground, and are so very tame that 

 once, when I was standing motionless, observing some War- 

 blers near me, one hopped between my feet to pick up a morsel 

 of food. I have often been able to make close observations 

 upon birds, by remaining entirely motionless and allowing 

 them to gather about me, and thus have accurately learned 

 their habits, without disturbing their happiness. 



d. The ordinary note of the " Black-throated Blues " is a 

 simple chip, which is sometimes closely repeated, after the 

 manner of the Chipping Sparrow. They have also a chatter, 

 employed chiefly as a battle-cry, and a loud alarm-note, resem- 

 bling the chuck of the Snow-bird. The males have an unmu- 

 sical song, the tone of which resembles somewhat that of the 

 Blue Yellow-back's song, or that of the Night Hawk's note, 

 being peculiar, and rather harsh or guttural. It usually con- 

 sists of three (rarely four) syllables, of which the last two are 

 the highest in tone and the most emphatic, and sounds like 

 " zwee-zwee-zwee." It is sometimes varied and lengthened so 

 as to resemble the syllables [che-ivee] che wee [see] wee-see 

 zwee. It is characteristic in tone, and is wholly unlike the 

 music of our other Warblers, with the exception of one form 

 of the song of the " Black-throated Green." * 



/. VIRENS. Slack-throated Green Warbler. " ^Black- 

 throated Green." In New England a common summer resi- 

 dent, but " rather confined to certain districts." f 



a. About five inches long. $ , olive green above. Wings 

 and tail, dark, with white-edged feathers ; former white-barred. 

 Whole side of head, rich yellow (with occasional indistinct 

 markings). Throat and breast, black. <j> (and (Jin autumn), 

 with the black restricted or wanting. Other under parts, 

 white or yellowish. Outer tail-feathers, largely white. 



* The tone is still more nearly like ginia juniper groves of southern New 



that of the song of the Golden-winged England, but also very common and 



Warbler. W. B. generally distributed throughout the 



t A summer resident most abundant, spruce and balsam forests of Maine, 



probably, in the white pine and Vir- New Hampshire, and Vermont. W. B. 



