The northern race of the white-headed woodpecker is found in the Cascade Mountains and the Sierra Nevada, from Washington to Kern County, Calif., and eastward into western Idaho and western Nevada.
It is a bird of the pine and fir forests in the mountains, ranging from 4,000 to 9,000 feet during the breeding season, but coming down to lower levels in winter. W. L. Dawson (1923) says: “This woodpecker is essentially a pine-loving species and is, therefore, nearly confined to the slopes of the Sierras and the Transition zones of the southern ranges. Only in winter does it appear at lower levels, and then rarely beyond the pale of the yellow pine. So close is this devotion of bird to tree that the woodpecker’s feathers are almost always smeared with pine pitch; and I have found eggs dotted with pitch and soiled to blackness by contact with the sitting bird.”
Clarence F. Smith writes to me that he found this woodpecker very common around a camp where he was located from June 25 to July 10, 1935, in Tuolumne County, Calif., in the Transition Zone at an elevation of about 4,000 feet. The camp was at one time a lumbering mill, and there was much dead standing timber nearby. Most of the trees were Pinus ponderosa and Pinus lambertiana.
Nesting.—The same observer says in his notes: “All the nests observed, except one in a Quercus kelloggii, were in dead standing stumps of the pines. The stumps were mostly some 12 to 15 feet in height, and the nests averaged about 8 feet above ground, with an approximate minimum of 6 feet. These nests may not represent a typical situation, as they were undoubtedly the ones that were most obvious to casual observation. Nests in higher locations would more easily escape notice. We had at least 8 nests within a half-mile radius of camp headquarters, and the birds were one of the commonest species in the vicinity. None of the nests opened contained any lining but chips of wood, and the cavities were about 14 inches in depth. None of the nest trees were less than 2 feet in diameter at the point where the nest was located. Many of the stumps had several holes in them, some of which had been nests in previous years, and some of which had been merely abortive attempts at drilling. The one nest in the oak, referred to above, was in a live tree with a decayed heart.”
Major Bendire (1895) writes:
Nidification usually begins about the middle of May and continues through June. The sexes relieve each other in the preparation of the nesting site, which is usually located in a dead stub of a pine or fir; one that is partly decayed seems to be preferred as it rarely excavates one in solid, hard wood. The nesting sites are seldom situated over 15 feet from the ground, and sometimes as low as 2 feet. The entrance hole is about 1½ inches wide, perfectly circular, and just large enough to admit the bird; the inner cavity gradually widens towards the bottom, and is usually from 8 to 12 inches deep, the eggs lying on a slight layer of fine chips, in which they become well embedded as incubation advances. Occasionally a rather peculiar site is selected. Mr. Charles A. Allen found a nest of this species in a post in one of the snow sheds on the Central Pacific Railroad, between Blue Canyon and Emigrant Gap, about 40 feet from the entrance of the shed, and some thirty trains passed daily within a few feet of the nest, which contained six eggs when found.
Milton P. Skinner sends me the following notes on nest building by this woodpecker: “On May 10, 1933, I found one at work on a hole in a stub of a tree, about 3 feet above ground. Although this was in the Sequoia National Park beside one of the most used paths, it was deepening the hole for a nest. Chips were scattered on the ground below. After pecking a while, the woodpecker would get into the hole and soon after back out again with a billful of chips. It then opened its bill and let them scatter to the ground; then back to work again. Although this was as public a place as could be found, and though the birds must frequently have been disturbed by the crowds of people and were within reach of hundreds of children, they succeeded in raising their brood of young. In spite of nesting so low, most of these birds are usually seen from 20 to 50 feet, and sometimes as high as 100 feet, above ground, working on the trees.”
Of ten nests found by Grinnell and Storer (1924) in the Yosemite region—
the lowest was located only 58 inches (measured) above ground and the highest, 15 feet (estimated). * * * No nest holes of this woodpecker were found in living conifers. Nor, on the other hand, do the birds seek what is commonly known as rotten wood, that is, wood too soft for the nest cavity to be maintained against the incessant wear involved in the birds’ passage back and forth, incident to the rearing of a brood. The tree chosen must have been dead a sufficient length of time for the pitch to have hardened or to have descended to the base of the tree, and the outer shell of the tree must still be hard and firm, whereas the interior must have been softened to a moderate degree by decay. These conditions are not to be met with in every standing dead stub; hence the choice of a nest site becomes a matter of rather fine discrimination.
They found plenty of evidence of this discrimination in the many unfinished nesting holes of varying depths that had been abandoned, often several in the same stub. “Some stubs are literally riddled with holes, these probably recording successive years of occupancy. One stub had at least 5 fully excavated holes besides 11 or more prospects. * * * We were led to conclude from all this that the White-headed Woodpecker is either notional or else very particular, in the selection of its home. Evidence points strongly to the birds excavating and occupying a new cavity each year, although one set of eggs was found in a hole which had been dug in earlier years.”