HAMMOND FLYCATCHER. Empidonax hammondi (Xantus)

Field characters.—Similar to those for Wright Flycatcher (which see) If seen at very close range, the following features (to judge from specimens in hand) might prove usable: Coloration both above and below as in Wright Flycatcher but darker more slaty gray; size, especially of bill, less. Voice: Like that of Wright Flycatcher, but less in volume and thought to be not so varied. Call note a weak pit; song, see'wit, pseet, swerz, etc., these three notes repeated many times with little variation.

Occurrence.—Moderately common summer visitant to Canadian Zone on west slope of Sierra Nevada. Recorded by us from Merced Grove and Chinquapin east to Porcupine Flat and Merced Lake. Found in migration at Pleasant Valley (May 25, 1915). One obtained in Yosemite Valley, September 23, 1917 (J. Mailliard, 1918, p. 18). Restricted closely to red fir forests during nesting season; forages singly, 20 to 100 feet above the ground.

The Hammond Flycatcher during its summer sojourn in the Yosemite region is a constant associate of the red firs. This of course means that it is found in only a limited portion of the Canadian Zone and only on the west side of the mountains. The Wright Flycatcher occurs in the same territory, as well as elsewhere, but it usually keeps near the ground in or close above brush patches, while the Hammond rarely strays below a height of 20 feet, keeping, rather, far aloft among the towering firs.

At Pleasant Valley, on May 25, 1915, Hammond Flycatchers were passing through in migration, although on May 25, 1919, birds of this species were found to be already located in the red firs at Tamarack Flat and even earlier (May 20) near Chinquapin. During the nesting season the species keeps close to its favorite forest trees, but after the broods of young are reared the young at least begin to wander higher into the mountains and to invade the Hudsonian Zone. On August 22, 1915, an immature bird was taken at 10,000 feet altitude on the north side of Mount Clark; two others were seen that day at 10,500 feet on the upper slopes of the same peak. The latest seasonal record is for August 28, 1915, when two immature birds were collected one mile east of Merced Lake. A small flycatcher seen at close range in this same locality on September 1, 1915, was thought to be a Hammond.

The call note of the Hammond Flycatcher is weaker than that of the Wright, being a soft pit. And the song is usually simpler and weaker in delivery than that of the Wright, and may be written as see' wit, pseet, swerz, etc. This three-part song is uttered at varying intervals for many minutes as the bird perches on the terminal twig of some outstanding dead branch two-thirds the way toward the top of a fir. When foraging the birds display considerable activity, changing their locations every 5 or 10 seconds. This may mean that flying insects are less abundant upward of 100 feet above the ground than at lower levels and must be more sought after there than within the forage range of the low-dwelling species of flycatchers.

No nests of the Hammond Flycatcher came to our notice, but birds taken in late June, 1915, gave indubitable evidence of nesting.