Nesting.—The first undoubted nests of the hermit warbler were found by C. A. Allen in Blue Cañon, California, two in 1886 and one about eight years previously, about which he wrote to William Brewster (1887): “All three nests were similarly placed;—in ‘pitch pines,' from twenty-five to forty feet above the ground, on thick, scraggy limbs, where they were so well concealed that it would have been impossible to find them except by watching the birds, as was done in each instance.” One of these nests held two eggs on June 4, but they were destroyed before they could be collected; the other two nests contained three young each. One of the nests with three young was sent to Brewster, who writes:
The nest with young, taken June 7, 1886, is now before me. It is composed of the fibrous stalks of herbaceous plants, fine dead twigs, lichens (Evernia vulpina), and a little cotton twine, and is lined with soft inner bark of some coniferous tree and fine long hairs, apparently from the tail of a squirrel. The bright, yellow Evernia, sprinkled rather plentifully about the rim, gives a touch of color to the otherwise cold, gray tone of the exterior and contrasts agreeably with the warm, reddish-brown lining. Although the materials are coarse and wadded, rather than woven, together, the general effect of this nest is neat and tasteful. It does not resemble any other Warbler’s nest that I have seen, but rather recalls the nest of some Fringilline bird, being perhaps most like that of the Lark Finch. It measures externally 4.50 inches in width by 2 inches in depth. The cavity is 1.25 inches deep by 2.50 inches wide at the top. The walls at the rim average nearly an inch in thickness.
Chester Barlow (1901), who has had considerable experience with the nesting of the hermit warbler in the central Sierra Nevada, refers to the records up to that time as follows:
On June 10, 1896, Mr. R. H. Beck collected a nest and four eggs from a limb of a yellow pine 40 feet up, near the American River at 3,500 feet altitude. The nest was reached by means of a ladder carried a long distance up the mountain. (See Nidologist, IV, p. 79). On June 14, 1898, I had the good fortune to discover a nest opposite the station at Fyffe, it being built at the end of a small limb of a yellow pine 45 feet up. The nest was located by searching at random and contained four eggs about one-fourth incubated. This nest was described at length in The Auk (XVI, pp. 156-161.) * * * While walking through the timber at Fyffe on June 8, 1899, Mr. H. W. Carriger came upon a nest of this species but 21⁄2 feet up in a cedar sapling. It contained four eggs, advanced in incubation. (See CONDOR I, pp. 59-60). A nest containing young about four days old found by Mr. Price’s assistant at Fyffe on June 11, 1897, was placed twelve feet up near the top of a small cedar, next to the trunk and well concealed. Thus it is probable that Fyffe has afforded more nesting records of this species than has any other part of the state.
Of the nest described in The Auk, Barlow (1899) says:
The nest was 45 feet from the ground in a yellow pine, built four feet from the trunk of the tree on an upcurved limb 18 inches from the end. * * * The nest is not fastened to the limb, resting merely upon the limb and pine needles and is wider at the bottom than at the top, its base measuring four inches one way and three inches the other. It is very prettily constructed, the bottom layer being of light grayish weed stems, bleached pine needles and other light materials held securely together by cobwebs and wooly substances. The nest cavity is lined with strips of red cedar bark (Libocedrus) and the ends, instead of being woven smoothly, project out of the nest. The inner lining is of a fine brownish fiber resembling shreds of soap-root. The composition of the nest gives it a very pretty effect.
J. H. Bowles (1906) found a nest in northwestern Washington on June 11, 1905, “in a grove of young hundred-foot firs near a small swamp.” The female sat so close that he was obliged to lift her from the nest with his hand—
and she then flew only a few feet where she remained chipping and spreading her wings and tail. * * * The nest was placed twenty feet from the ground in a young fir, and was securely saddled on a good sized limb at a distance of six feet from the trunk of the tree. It is a compact structure composed externally of small dead fir twigs, various kinds of dry moss, and down from the cottonwood flowers, showing a strong outward resemblance to nests of D. auduboni. But here the likeness between the two is at an end; for the lining consists of fine dried grasses, and horsehair, with only a single feather from the wing of a western bluebird. The measurements are, externally, four inches in diameter and two and three-quarters inches deep; internally, two inches in diameter by one and a quarter inches deep.
A nest in the Thayer collection in Cambridge was collected by O. W. Howard “70 feet above ground, near the end of a limb of a yellow pine, in a bunch of needles,” in Tulare County, Calif. Gordon W. Gullion tells me of an Oregon nest that was “about 125 feet above the ground.”
Eggs.—The hermit warbler lays 3, 4, or 5 eggs to a set; 5 are apparently not rare. Bowles (1906) says of his 5 eggs: “They have a rather dull white ground with the slightest suggestion of flesh color, heavily blotched and spotted with varying shades of red, brown and lavender. * * * I think they may be considered the handsomest of all the warblers’ eggs.” The 4 eggs in the Thayer collection in Cambridge are ovate, with a very slight lustre. They are creamy white, finely speckled and spotted with “chestnut” and “auburn,” with intermingling spots of “light brownish drab.” The markings are concentrated at the large end, forming a broad, loose wreath. The measurements of 50 eggs average 17.0 by 13.1 millimeters; the eggs showing the four extremes measure 18.0 by 13.4, 17.0 by 13.7, 15.2 by 12.7, and 16.3 by 11.8 millimeters (Harris).