372 ANIMAL LIFE IN THE YO SEMITE 



of this song. Our latest record, seasonally, is for September 17 (1915), 

 when an immature female was taken near Williams Butte. The latest 

 record for the species in Yosemite Valley is for September 11 (1920) 

 (C. W. Michael, MS). 



On Smith Creek, at Dudley, July 14, 1920, a nest was found in a 

 springy place grown luxuriantly to willow, azalea, and blueberry. The 

 nest, measured to the level of the rim, was 37 inches (940 mm.) above 

 the ground, built into the five upright forks of an azalea stem, well beneath 

 the general foliage 'ceiling.' The bird sat until approached within a 

 distance of six feet. There were 3 buff-toned Q^^f^ with brown spots, 

 opaque, and therefore far incubated. The nest was the usual compact 

 cup -like structure and consisted entirely of gray weathered bark fibers. 



Western Flycatcher. Empidonax difficilis difficilis Baird 



Field characters. — Similar to those for Wright Flycatcher (which see). Upper sur- 

 face of body olive green, under surface definitely yellowish; lower mandible wholly 

 yellow beneath. Voice: Call note a clear shrilly whistled swee'ip; song, a shrilly three- 

 part, see'rip, sip, see'rip, repeated at short intervals. 



Occurrence. — Sparse summer visitant to Transition Zone on west side of Sierra 

 Nevada. Observed in Yosemite Valley from May 1 (1916) to July 30 (1915), at Merced 

 Grove Big Trees, and along Smith Creek (east of Coulterville). Frequents chiefly wooded 

 canon bottoms where incense cedars and alders line the streams. Forages singly, and 

 perches 10 to 25 feet above the ground. 



We found the Western Flycatcher to be rare and local in the Yosemite 

 region, and restricted to the Transition Zone. A single individual was 

 noted at the McCarthy Ranch (altitude 3200 feet) at the beginning of 

 the forest, 3 miles east of Coultervdlle, and Mr. Donald D. McLean has 

 record of a nest at Dudley, a short distance farther east. Two individuals 

 were seen at Merced Grove Big Trees. All our other records pertain to 

 Yosemite Valley, one of which, made at 5700 feet, on the Yosemite Point 

 Trail, marks the highest place at which the species was obser^^ed. Season- 

 ally the records range from May 1 (1916) to July 30 (1915), both dates 

 for the Valley itself. To JTidge from observations in other parts of Cali- 

 fornia, it seems likely that the birds arrive somewhat earlier and depart 

 later than the limiting dates just given. Our observations on the floor 

 of Yosemite Valley were not continuous during the seasons of migration. 



The Western Flycatcher exhibits the same traits in posture and forage 

 habits as do other members of the flycatcher family. AVhen on the lookout 

 for insects, an occupation which fills most of its waking hours, it sits on 

 some twig in erect rather than horizontal posture and there turns its head 

 from side to side, darting out in rapid flight after any suitable insect 

 which may chance to pass close at hand. The Western Warbling Vireo 



