AUDUBON WABBLES 529 



an equal number of Western Bluebirds. The Audubon Warbler is thus 

 more sociably inclined than any other member of its family found regularly 

 in the Yosemite section. 



In the fall the Audubons range widely, some keeping to the middle 

 altitudes, others dropping to the lowlands or moving south, while a few 

 may range even above timber line. On September 6, 1915, while one of 

 us was traversing the south slope of Parsons Peak at an altitude of 11,500 

 feet, a lone Audubon Warbler flew past. Others had been seen in the 

 dwarfed pines near Vogelsang Lake at 10,350 feet altitude a few days 

 earlier. Of all our warblers the Audubon is the hardiest as regards ability 

 to stand the cold and storms of the winter season at the lower levels and 

 the variable weather of the summer season at the upper altitudes. 



Black-throated Gray Warbler. Dendroica nigrescens (Townsend) 



Field characters. — Half bulk of Junco. Head, chin, and throat black (mixed with 

 ■white in female and young), with a white line backward over eye and another from 

 bill down side of throat; sides of. body streaked with black; rest of under surface white; 

 upper surface bluish gray; two light bars on wing; tail white margined. No con- 

 spicuous yellow in plumage. (See pi. 9/.) Movements rather deliberate for a warbler. 

 Voice: Song of male a slow drawling wee'-zy, wee'-sy, wee'zy, wer; call note a low chit. 



Occurrence. — Moderately common summer visitant locally in Transition Zone on 

 west slope of Sierra Nevada. Eecorded from 3 miles east of Coulterville eastward to 

 Yosemite Valley. Seen in fall migration near Mono Lake. In nesting time practically 

 restricted to golden oaks. Solitary or in scattering parties. 



The Black-throated Gray Warbler is a bird of the golden oaks and is 

 to be found in fair numbers in the heavy growths of these trees which 

 clothe the talus slopes along the north and south walls of Yosemite Valley. 

 Elsewhere in the Yosemite section the species was found only in stands 

 of this same oak or in nearby situations. This warbler is therefore notable 

 for being one of the very few birds which, in the Yosemite section, is 

 entirely restricted to the Transition Zone. The Yosemite Falls Trail below 

 Yosemite Point, the Glacier Point short trail below Union Point, the Big 

 Oak Flat road below Gentrys, and the Little Yosemite trail below Nevada 

 Falls are good places from which to study this warbler, for all these trails 

 pass through golden oaks. 



This bird is preeminently a black and white warbler. (See pi. 9/.) 

 At a distance no yellow shows (though a small spot of this color is present 

 in front of the eye). In this feature the bird departs from the color 

 scheme of its local relatives, all of which show, even at a distance, more 

 or less yellow. In the adult male of the present species the head, chin, 

 and throat are chiefly black. The female has less black, her chin often 

 being mixed black and white ; this is true also of the young. Adults and 



