The downy woodpeckers of California were for many years all called D. p. gairdneri, until Dr. Walter K. Fisher (1902) called attention to the smaller and lighter-colored race, which inhabits much of the coast region and nearly all the lowlands of southern California. For this race, he very properly revived Malherbe’s name, as given above, for this name was based on birds taken near Monterey. He gives as the characters of the willow woodpecker:
Smaller than Dryobates pubescens gairdneri, with smaller feet; under parts lighter; the elongated superciliary patch and rictal stripe extending over sides of neck, pure white, instead of smoky white of gairdneri; tertials always more or less spotted with white. * * *
Dryobates pubescens turati is a southern representative of gairdneri, which it resembles in the smoky under parts and restricted areas of white on the wings, and from which it differs in its smaller size, much smaller feet, and clearer white markings of head. The present form is near true pubescens of the Southern States, but differs from it in having much less white on the wings, the coverts and tertials of pubescens being conspicuously and often heavily marked with white. * * *
The willow woodpecker in a typical form breeds from Los Angeles and San Bernardino counties north in the coast ranges to San Francisco Bay, and along the west slope of the Sierra Nevada at least to Yuba County. Intergradation with gairdneri occurs over the coast region north of San Francisco Bay and in the mountains at the head of the Sacramento Valley.
Grinnell, Dixon, and Linsdale (1930) say of the haunts of the willow woodpecker in the Lassen Peak region: “Downy woodpeckers were seen most often close to streams and in orchards. Their forage places included the limbs or small trunks of willow, alder, cottonwood, sycamore, valley oak, blue oak, digger pine, and yellow pine trees.”
Nesting.—Major Bendire (1895) writes: “Mr. Charles A. Allen informs me that it breeds in the oaks and willows along the Sacramento River, Calif., but that it is not common. Its breeding sites seem to be confined to deciduous trees, preferably dead ones, or old stumps, and besides those already mentioned, sycamore and cottonwoods are occasionally used. Their nesting sites are rarely found at any great distance from the ground, usually ranging from 4 to 20 feet up and rarely higher.”
W. L. Dawson (1923) says: “Willow woodpeckers, in the wild, place their nests at considerable heights in deciduous trees, and those, if possible, among thick growths on moist ground. Both sexes assist in excavation, as in incubation. Partially decayed wood is selected, and an opening made about an inch and a quarter in diameter. After driving straight in for an inch or two, the passage turns down and widens two or three diameters. At the depth of a foot or so the crystal white eggs are deposited on a neat bed of fine chips. Incubation lasts twelve days, and the young are hatched some time in May.”
Eggs.—The willow woodpecker lays three to six eggs, more commonly four or five; it may occasionally lay seven, as some of the other western races have been known to do. The eggs are typical of the species. The measurements of 40 eggs average 18.74 by 15.20 millimeters; the eggs showing the four extremes measure 22.3 by 15.7, 18.4 by 16.3, 17.3 by 14.5, and 18.0 by 14.4 millimeters.
Food.—Mr. Dawson (1923) writes:
It is as an orchardist that the Willow Woodpecker deserves the most careful consideration. Bird-lovers are, perhaps prone to superlatives in commending their friends, but it is safe to say that a more useful bird for his ounces than the downy woodpecker does not exist. He eats not only ants and the larvae of wood-boring beetles, but scale insects, plant lice, and the pupae of the detestable coddling moth. The evidence is clear that these incomparable tree experts, together with their friends, the nuthatches, the chickadees, and the creepers, would insure the health of our orchards if they were numerous enough. It becomes of the highest importance, then, to study their welfare in turn. In the northern and more elevated valleys of the State, it may be worth while to offer them nuts or to hang out a bit of suet in winter. In the South no such precautions are necessary. A fundamental consideration, however, is the provision of suitable nesting sites. Experiment has shown that the downy’s forage range during the breeding season is not extensive. The clamoring young are fed by the product of nearby trees (fed, it may be, a thousand insects a day). Their services, therefore, must be secured in the orchard; and to this end the orchardist must consent to leave certain dead branches—a foot or so at the base of the larger ones will do—for a nesting site. Dead wood, of course, invites insects; but the most serious and frequent mistake which our California orchardists make is to trim out all the dead wood from the fruit trees. A pair of Willow Woodpeckers, or of Slender-billed Nuthatches, will clean out all the dangerous pests from a dead tree, and sixteen live ones to boot.