CABANIS’S WOODPECKER
HABITS
The hairy woodpeckers of the coast district of California from Mendocino County southward, the mountains of southern California, and the southern Sierra Nevada, as far east as White Mountains of California, are now known by the above name. This race is somewhat smaller than harrisi and decidedly smaller than orius, its neighboring races to the northward; its under parts are much lighter colored than in harrisi; these parts are described by Ridgway (1914) as “dull grayish or brownish white or pale drab-grayish or buffy grayish.” This and the Sierra woodpecker (orius) seem to form connecting links between the dark-breasted harrisi and the white-breasted Rocky Mountain forms, monticola and leucothorectis, both of which are decidedly larger also.
Dr. Joseph Grinnell (1908) says of the distribution of this woodpecker in the San Bernardino Mountains in southern California: “This was the most widely distributed species of woodpecker in the region, occurring throughout the timbered portions, irrespective of zones. It was common from Santa Ana Cañon to the summit of Sugarloaf, 9,800 feet, and nearly to timber line on San Gorgonio peak. On the desert side the species was noted as low as Cactus Flat, 6,000 feet, where one was seen in some golden oaks in a ravine, August 16, 1905.”
Courtship.—The drumming of woodpeckers in the spring on some resonant limb or tree trunk is an important part of the courtship urge, as a warning to any rival, or as a call to a possible mate. Dr. Grinnell (1908) shows how the manner of drumming may also serve as a recognition call; he says: “The resonant rattling drum identified this species from any other of this region. Near Dry lake, 9,000 feet altitude, dead tamarack pines were selected for this purpose, and on June 23, 1905, I listened for many minutes to a remarkable demonstration of this kind. Different branches were tattoed in rapid succession, so that a xylophone-like variety of tones was produced, very impressive and far-carrying through the otherwise quiet forest.”
Nesting.—Major Bendire (1895) writes:
In California Cabanis’ Woodpecker is common in the mountains, but in the lowlands in the southern part of this State Mr. F. Stephens considers it a rather rare summer resident. He found it breeding in a cottonwood tree, near San Bernardino, on March 21, 1885. Mr. Lyman Belding took several nests of this subspecies in Calaveras County, in the Sierra Nevadas; in one, found on June 6, 1879, which had been excavated in a dead pine stump, 12 feet from the ground, the eggs, three in number, were on the point of hatching. In his notes he says: “I scared the female from it and prevented her return by inserting a stick, the end of which protruded for several feet. When she found she could not enter she gave several cries, which brought the male, who hopped up and down the stick a few times, striking it with his bill and screaming angrily, pausing occasionally, and apparently deliberating on the best method of extracting it.” Another nest, found by him on July 10, 1880, was located only 3 feet from the ground, and contained young which were still in the nest on the 20th. Mr. Charles A. Allen informs me that along the Sacramento River, in California, it breeds in sycamores and willows, but that it is not common there.
Eggs.—Major Bendire (1895) says:
The number of eggs laid to a set varies from three to six; those of four are by far the most common; sets of five are only occasionally met with, while sets of six are very unusual. * * * The eggs lie on the fine chips left in the bottom of the cavity, and are occasionally well packed into these, so that only about one-half of the egg is visible. They resemble the eggs of Dryobates villosus in color, but those of an elliptical ovate shape are more common than the oval and elliptical ovals, averaging, therefore, more in length, while there is proportionally less difference in their short diameter.
The measurements of 23 eggs average 24.49 by 18.38 millimeters; the eggs showing the four extremes measure 25.7 by 18.2, 24.2 by 19.7, 22.8 by 18.1, and 24.9 by 16.5 millimeters.
Young.—Mrs. Irene G. Wheelock (1904) says: “Both sexes share the labors of excavating, brooding the eggs, and feeding the young. Incubation lasts about fifteen days, and the young remain nearly four weeks in the nest, being fed most of that time by regurgitation. After leaving they are fed by the parents for at least two weeks, and usually return to the nest at night to sleep.”
Food.—W. Leon Dawson (1923) writes: “Nearly half of the Cabanis Woodpecker’s food consists of the larvae of wood-boring beetles (the Cerambycidae and Buprestidae); and of the remainder the caterpillars of various injurious moths form a large per cent. Wild raspberries and blackberries are eaten in summer, and certain hardy fruits, such as cornel berries, acorns, and the pits of the islay, or evergreen cherry (Prunus ilicifolia), eke out the winter sustenance.”
Referring to its manner of feeding, Milton P. Skinner says in his notes: “On August 10, 1933, I saw a Cabanis working on both the trunk and the limbs of a small Douglas fir. It worked all around a horizontal limb and really seemed to be under the limb more than above. It also worked on upright branches as well. I have also seen a Cabanis feeding on the bark of a lodgepole pine. One day I found one on a dead black oak, scaling off dead bark to get at the insects beneath. So far as I can tell, these birds, in the Sequoia National Park, seem to prefer to pick food from the surface and furrows in the bark, and do not bore into the bark and wood as much as other woodpeckers. During my work among the Big Trees, I noticed that these birds seem to avoid the sequoia’s bark; but at one place I found a living tree with many holes bored in the old wood of its charred base, where it was unprotected by bark.”
Behavior.—Mr. Skinner’s notes say that “this woodpecker has quite a few mannerisms of its own. One, seen flying across a meadow, went first to the limbs of Douglas firs, then to a small dead limb of a sequoia, then to the limb of a fir, and then to the trunk of the same fir. It perched lengthwise of limb and trunk each time. And this procedure was followed again and again on different days. Usually the Cabanis perches crosswise on a horizontal limb, especially when resting or preening, but lengthwise on erect, or nearly erect, trunks and limbs when feeding.
“Although this woodpecker almost always flies to the exact spot it selects, its flight through the forest is undulatory. The undulations are due to the fact that it progresses by a series of wing beats. At the end of each series, it seems to actually close its wings and shoot forward with the impetus gained.”