On June 18, 1934, a nest of this species was found at 6,000 feet altitude on Hart Mountain, Lake County, Oregon. The location was a rather dense mixed grove of aspen, alder, willow, and yellow pine. The female was on the nest, which was placed on the ground well under a small leaning willow stump, about five inches in diameter, that had been cut off about a foot above the ground, leaving the stump leaning at an angle of about 45 degrees. Weeds had grown over the stump forming a loose canopy of vegetation which protected the nest and sitting bird from being easily seen. The nest was composed of coarse dry strips of willow bark, lined with porcupine hairs. It measured, inside, 50 mm. in width and 33 mm. in depth.
A nest and four eggs of this species, probably orestera, is in the Thayer collection in Cambridge; it was collected at Banff, Alberta, on June 9, 1902. The nest was said to be "in root of a shrub, a few inches above the ground". It is compactly made of the finest larch twigs, yellow birch bark, fine shreds of coarse weed stems, other fine plant fibers and fine grasses, fine strips of inner bark, and a little plant down; it is lined with finer pieces of the same materials and some black and white hairs. The outside diameter is about 3 inches, and the height about 2 inches; inside, it measures about 13⁄4 inches in diameter and 11⁄4 inches in depth. A set of three eggs in my collection was taken May 14, 1909, near Glacier National Park, Mont.; the nest was on the ground, concealed by grass on a hillside. The measurements of the eggs of this race, which are indistinguishable from those of other races of the species, are included in those of the type race.
VERMIVORA CELATA LUTESCENS (Ridgway)
LUTESCENT ORANGE-CROWNED WARBLER
HABITS
This brightly colored race of the orange-crowned warbler group is widely distributed during the breeding season along the Pacific coast regions from southern Alaska to southern California and migrates in the fall southward to Baja California, western Mexico, and Guatemala. It differs from typical celata in being more brightly olive-green above and distinctly yellow below; in strong light it seems to be a yellow rather than an olive bird.
Dr. Walter K. Fisher sent the following sketch of it in its California haunts to Dr. Chapman (1907):
Chaparral hillsides and brushy open woods are the favorite haunts of the Lutescent Warbler. Its nest is built on or near the ground, usually in a bramble tangle or under a rooty bank, and the bird itself hunts near the ground, flitting here and there through the miniature jungle of wild lilacs, baccharis and hazel bushes. Its dull greenish color harmonizes with the dusty summer foliage of our California chaparral, and with the fallen leaves and tangle of stems that constitute its normal background. It impresses one chiefly by its lack of any distinctive markings, and the young of the year, particularly, approach that tint which has been facetiously called “museum color.”
Ordinarily the crown-patch is invisible as the little fellow fidgets among the undergrowth, but at a distance of 3 feet Mr. W. L. Finley was able to distinguish it when the bird ruffled its feathers in alarm.