TRAILL FLYCATCHER. Empidonax trailli trailli (Audubon)

Field characters.—Similar to those for Wright Flycatcher (which see). Coloration above more brownish, beneath less deeply grayish than in that species, nearly white. Voice: A rather soft though staccato whit', or quip', given sometimes 2 or 3 times in quick succession; also a song consisting of many repetitions of a phrase resembling wheet-p 'teer.

Occurrence.—Common summer visitant locally in Sonoran Zones, and lower part of Transition Zone (chiefly in Yosemite Valley), on west slope of Sierra Nevada; also in Transition Zone in vicinity of Mono Lake. Restricted to willow thickets of broad bottomlands. Met with in pairs which keep close to cover among the willow stems.

The Traill Flycatcher is essentially a bird of the extensive tracts of willows marking the meandering stream courses in the broader bottom lands. In the Yosemite region it is most abundant in the Merced river-bottom near Snelling. Yet it finds conditions favorable again, after the long interval of narrow cañon, on the floor of Yosemite Valley and is fairly common there during the midsummer season. It occurs in the same season east of the mountains, along the lower stream courses in the vicinity of Mono Lake. The bird's soft-toned yet short call notes, resembling somewhat those of the Russet-backed Thrush though not so full-toned, and the restricted type of habitat, must ordinarily be depended upon to identify this flycatcher. No other small flycatcher is found in close association with this species during the nesting season. The Traill adheres closely to the cover of thickets; it must be looked for beneath the level of the willow tops. It is thus very different in perch predilection from most of the other Empidonaces.

On July 30, 1915, a nest of the Traill Flycatcher was found in a blackberry bush which grew beside a small slough or ditch near the Yosemite Valley schoolhouse. The nest was 3 feet above the ground in the outer edge of the bush; it was made of grass and weed stems and lined with horsehair. It contained three small young. One parent bird was about and acted with great concern; but it was shy to the extent of keeping well hidden within the foliage of the vegetation bordering the slough, whence it uttered a series of anxious notes. On May 17, 1919, the Traill Flycatchers were already present in Yosemite Valley. A male heard in full song on that date repeated over and over again with trying sameness a phrase something like wheet-p'teer. The bird was so much of the time out of sight that its location was to be guessed mainly from the direction 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 eggs 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.