516 ANIMAL LIFE IN THE TOSEMITE 



Calaver vs Warbler. Vermivora ruficapilla gutturalis (Ridgway) 



Field cTiaraciers. — Half bulk of Junco. Body coloration yellow beneath, olive green 

 above; head and neck (except throat) gray; eyelids white; male has a chestnut colored 

 crown patch, visible only at close range. No white or black markings whatsoever on 

 wings or tail. (See pi. 9o.) Voice: Song of male 4 or 5 rapidly uttered shrill notes 

 followed by 3 or 4 lower ones: tsirp, tsirp, tsirp, tsirp, sup sup sup; call note a tseep, 

 or tsit. 



Occurrence. — Common summer visitant to Transition Zone on west slope of Sierra 

 Nevada. Kecorded from 3 miles east of Coulterville and from Sequoia eastward to 

 Yosemite Valley and slopes adjacent. Highest stations, at 7400 feet altitude near Mono 

 Meadow and at 6700 feet above Yosemite Falls. Some few individuals wander higher 

 in mountains after nesting (for example, 8000 feet on McClure Fork of Merced River, 

 August 29, 1915). Sings and forages 10 to 70 feet above ground in broad-leaved trees 

 such as black oak and maple, but nests in shaded situations on ground. Solitary. 



The Calaveras Warbler is common during the summer months in the 

 black oaks and maples along each side of Yosemite Valley and in similar 

 situations elsewhere on the western flank of the Sierra Nevada. Among 

 all the warblers to be seen in the Yosemite Valley during the summer 

 months the present species is the only one which does not forage and nest 

 in the same niche. The Calaveras seeks its food and does its singing well 

 up in trees, but places its nest immediately upon the ground. 



The niche of the Calaveras Warbler is not invaded by any other species 

 of warbler, although other birds of this group may be close around. (See 

 fig. 56.) In the pines and cedars are the Audubon and Hermit warblers, 

 the golden oaks of the talus slopes harbor the Black-throated Gray Warbler, 

 and in the stream-side willows and cottonwoods is the Yellow Warbler ; 

 while the tangles of underbrush above moist ground on the Valley floor 

 shelter Tolmie and Golden Pileolated warblers. 



During May and June the song of the Calaveras Warbler may be 

 heard frequently, for the males sing at short intervals through most of 

 the day. One bird watched near Columbia Point on June 2, 1915, was 

 singing at intervals of 7 to 12 seconds, each utterance occupying but a 

 second or two. The pitch is high although the notes are not so piercing 

 as those of a Yellow Warbler and the song as a whole suggests that of the 

 Laziili Bunting. Four or five notes are given sharply and distinctly, then 

 three or four less sharp ones are uttered in more rapid time. Three phras- 

 ings of the song written by us in the field are as follows : tsirp, tsirp, tsirp, 

 tsirp, sup sup sup; tsu'-ip, tsu'-ip, tsw'-ip, tsu'-ip, seet-seet-seet-seet ; again 

 seit, seit, seit, seit (4 or 5), che-che-che-cha. Sometimes the terminal group 

 of syllables is omitted. 



