WESTERN WOOD PEWEE. Myiochanes richardsoni richardsoni (Swainson)

Field characters.—Size of Junco, with posture and habits of flycatcher. Plumage above and on sides of body dark brown; middle of lower surface of body yellowish white. No special markings whatever: no white flank patch, no light eye-ring, wing bars wanting or else but faint. Perches in upright, straight-backed posture on lower bare branches of large trees whence it darts out after flying insects. Voice: A throaty, slurred zuweez, or zweer, repeated at intervals throughout the day, more frequent (often every 2 or 3 seconds) in early morning and late evening.

Occurrence.—Common summer visitant to Upper Sonoran, Transition, and Canadian zones on both slopes of Sierra Nevada. Observed from Snelling (in migration) to Mono Craters. Seen in Yosemite Valley throughout the summer. Arrives about second week in May and departs about mid-September. Usual forage range about 15 to 40 feet above ground. Solitary except when caring for brood.

The Western Wood Pewee is the commonest and most widely distributed flycatcher found in the Yosemite region. In form and coloration it resembles somewhat the Olive-sided Flycatcher, but it is of slenderer build, lacks the white flank patches of the latter species, and the voices and forage ranges of the two birds are quite different. The size, of course, is much less.

From the smaller flycatchers (genus Empidonax), the wood pewee is not very easily distinguishable on grounds of coloration alone. When closely inspected, the absence of wing bars, or if these are present, as in the young pewees, their relative dimness, is a serviceable field character, as also is the presence of a light area down the middle of the bird's under surface. The wood pewee, moreover, has no suggestion of an eye-ring, which feature, due to the white or yellowish color of the circlet of small feathers immediately around the eye in the Empidonaces, give these smaller flycatchers a distinctive, big-eyed expression.

The monotonous droning call of the pewee is altogether unique. This note is one of the commonest of bird voices heard at all places, from the first digger pines of the foothills to the limit of the red firs and Jeffrey pines at the upper margin of the Canadian Zone. Wood pewees are active and calling from earliest dawn until after dark. They occasionally wake in the middle of the night to voice a call or two.

The forage range of this bird is usually about the lower periphery of the forest trees and from about 15 to 40 feet above the ground. It has no close restriction to one particular habitat or species of tree as do the smaller flycatchers (genus Empidonax), and it may be seen in a great variety of situations. Occasionally it seeks the top of a tree, after the manner of the Olive-sided Flycatcher, but it rarely if ever goes so high above the ground as that bird.

The earliest record at hand for the Western Wood Pewee in the Yosemite section is for May 9 (1919) when several were seen at Blacks Creek near Coulterville. None had been seen in the preceding four days in the lower foothills, nor were any pewees observed in Yosemite Valley on May 1, 1916. The second week of May evidently marks the time of arrival of this species in the region. At Snelling, on May 26, 1915, wood pewees were still in migration, for they were then seen in all sorts of surroundings. Two days earlier, at Pleasant Valley, 20 were recorded in a 5-hour census, many more than would likely have been seen in an equal period of time after the migrant contingent had moved on. By May 30 they had decreased, only 3 being observed in 3-1/2 hours. East of the Sierras near Williams Butte the species was first noted in 1916 on May 18.

A Western Wood Pewee watched in the forest east of Coulterville, June 1, 1915, occupied in succession, as forage perches, the terminal twigs of a yellow pine, a fence wire, and the dead limbs of a black oak. At timed intervals of 15, 10, 15, 10, 15, and 15 seconds it flew out after passing insects. After taking something particularly large it gulped several times before swallowing the insect and then carefully wiped its bill on a convenient twig. Between sorties after prey the bird uttered its monotonous call note at short intervals. Near Porcupine Flat a wood pewee was found to have a much frequented perch in a certain tree and on the ground immediately beneath the perch there was an accumulation of droppings indicating occupancy for a considerable time.

In the woods on the north side of Yosemite Valley west of Rocky Point a wood pewee was seen on her nest on May 18, 1919. This early date of nesting for a species of late arrival indicates that some pairs lose little time in settling down to the important duties of the season. This nest was about 40 feet above the ground on a dead horizontal branch of a black oak, well shaded by the new green foliage above. It was situated at a turn in the branch where two small broken-ended twigs started, and from below, it looked like little more than a slight swelling of the branch. The bird was moving about and seemed to be working on the rim with her bill; the nest was evidently still in process of construction. She left, to return soon accompanied by her mate, who uttered a series of low notes, per, per, per. She went on the nest again and worked around in it for a few minutes and then again arched her neck, turning her head downward as if modeling or adding again to the rim.

The nesting season of the wood pewee extends over a long time. In Yosemite Valley on July 27, 1915, a family of full-grown young was seen still attended by the parents, and a similar observation was made at Tenaya Lake on July 29, 1915. Near Merced Lake on August 23, 1915, a Western Wood Pewee was seen in vigorous pursuit of a Sierra Chickaree. The bird was scolding furiously, while the squirrel retreated as fast as possible. Since the wood pewee is known to continue its nesting into August, the bird's repulsion of the squirrel may have been incited by a raid upon its nest.

The latest records we have for the Western Wood Pewee in the fall are for September 9, 1915, at Walker Lake, and for September 13, 1915, at Agnew Lake, when four were seen in lodgepole pines. The last seen in 1920 on the floor of Yosemite Valley was noted on September 13 (C. W. Michael, MS).