484 ANIMAL LIFE IN THE YOSEMITE 



is disturbed or excited. Thus when the two nests mentioned above were 

 being examined, the owners remained in the vicinity, at a distance of 30 

 or 40 feet, hopping about on the ground, exhibiting some concern, and 

 voicing a kitten-like mew-wee. 



East of the Sierras in the fall months the number of Green-tailed 

 Towhees seems to be augmented over and above the normal seasonal 

 increase by the appearance of migrants. When trapping for mammals 

 was being carried on in the sagebrush near Williams Butte several of 

 these towhees, attracted by the rolled oats placed on the traps as bait, fell 

 undesired victims. 



We have no data as to the time of arrival of the Green-tailed Towhees 

 on the west side of the Sierras, nor is the route of their migration thither- 

 ward known. On the east side, at Williams Butte, the first was seen in 

 1916 on May 6, after which the species was common. They were still there, 

 at least as migrants, on September 22 (1915), when field work for the 

 season was concluded in that locality. In Yosemite Valley on October 2, 

 1915, Green-tailed Towhees were frequenting the same thickets as the 

 Golden-crowned Sparrows which had then just arrived from the north. 

 The Green-tails were evidently on the verge of departing, as the last record 

 for the season is of one seen near Glen Aulin on October 4, 1915, although 

 field observations were continued on the west slope that year until late in 

 November. 



Mr. Joseph Mailliard (1918, p. 15), who visited Yosemite Valley from 

 August 18 to September 29, 1917, states that he found no Green-tailed 

 Towhees there until September 5 ; after that date they increased in numbers 

 until, in favorable spots, such as the eastern end of Sequoia Lane, 8 or 10 

 could be seen within 200 yards. 



Pacific Black-headed Grosbeak 

 Zamelodia melanocephala capitalis Baird 



Field characters. — Between Junco and Eobin in size; tail shorter than body; bill 

 large and blunt. Adult male in summer: Upper surface largely black; end of tail and 

 middle of wing with large spots of white; collar around hind neck, rump, and under 

 surface of body, light reddish brown. Female and immature: Head with a light stripe 

 over each eye and another over crown; rest of upper surface dull brown, streaked with 

 blackish; under surface brownish white. Yearling males often wear a plumage inter- 

 ' mediate between that of adult male and of female. Voice: Song of male elaborate — a 

 rapidly timed series of full warbling notes with both ascending and descending inflec- 

 tion; call note, uttered by both sexes, a sharp spick. 



Occurrence. — Abundant summer visitant at lower altitudes on both sides of Sierra 

 Nevada (chiefly in Upper Sonoran and Transition zones). Eecorded from Snelling and 

 near Lagrange eastward to Hazel Green, floor of Yosemite Valley, and near Chinquapin; 

 also at Mono Lake Post Office and near Williams Butte. Forages largely in crown 

 foliage of deciduous trees, sometimes in shrubs, occasionally on ground. Non-flocking. 



