WESTERN YELLOW-BELLIED FLYCATCHER.
Empidonax difficilis, Baird, Birds N. Am. 1858, 198 (under E. flaviventris) pl. lxxvi, f. 2.—Sclater, Catal. 1862, 230. Empidonax flaviventris, Cooper, Orn. Cal. 1, 1870, 328.
Sp. Char. Similar to flaviventris, but tail much longer, and colors lighter and duller. The olive above less green, and the sulphur-yellow beneath less pure, having an ochraceous cast, this especially marked on the edge of the wing; wing-bands grayish rather than yellowish white. Measurements, ♂ (58,550, Parley’s Park, Wahsatch Mountains, Utah, August 5, 1869; C. King, R. Ridgway): Wing, 2.90; tail, 2.80; wing-formula, 3, 4, 2, 5, 6, 1. Young. Wing-bands ochraceous, instead of grayish-white, with a sulphur-yellow tinge.
Hab. Western Province of United States, and Western Mexico. (Mazatlan, Colima, etc.) Fort Whipple, Arizona (Coues, P. A. N. S. 1866, 62).
Habits. This Flycatcher is a western form, closely allied to our eastern E. flaviventris. It was met with by Dr. Coues in Arizona, where it was rather rare, and appeared to be a summer resident. It arrives in that Territory about the middle of April, and remains there until the latter part of September. Dr. Coues found it difficult to distinguish this form from our eastern flaviventris.
Dr. Cooper obtained at Monterey, Cal., specimens of the western types of this bird, having darker markings on the wing, which, however, he regards as only indicative of a young plumage, and not of specific distinctness. He found these birds chiefly frequenting woods of Coniferæ, and very silent, which, so far as the observation has any value, indicates a marked difference between the eastern and the western birds.
The eggs of this species are also different from any of the eastern E. flaviventris that I have ever seen, and are more like the eggs of E. trailli than of the other species of Empidonax. They measure .73 of an inch in length, by .58 in breadth, have a creamy-white ground, marked at the larger end with reddish-brown and purplish markings. They are of an oblong-oval shape. Mr. Ridgway met with this species only once in his western explorations, when he obtained a pair in a thick pine woods on the Wahsatch Mountains, in June. They were exceedingly retiring, and frequented dark woods, whose solitudes were shared besides only by the Turdus auduboni and Myiadestes townsendi. Their note was a pit, much more like that of some Warblers than like the notes of the other Empidonaces.
This species, called by Mr. Grayson “The Lonely Flycatcher,” was found
by him quite common in the Three Marias, islands off the Pacific coast of Mexico, as well as on the main coast, and also in California. The accustomed places of resort of this solitary little bird were, he states, the most retired and secluded dells of the forest. He there met with it beneath the canopy of the natural and shady grottos formed by the overlapping branches, intermingled with innumerable creeping plants, sitting upon some low twig watching for a passing fly. At other times it might be seen frequenting some secluded and shady little brook, near the surface of which it often darted upon the flies that skimmed over the surface of the water, ever and anon uttering a low and plaintive one-syllabled note.
Empidonax obscurus, Baird.