The young female is similar to the young male, except that the red of the crown is more restricted and the forehead is streaked with white. This plumage is, apparently, worn all through the first summer; I have seen young birds in this plumage as late as August 30. Probably early in fall a postjuvenal molt produces a plumage that is practically adult. I have been unable to learn anything about the molts of adults. Ridgway (1914) says that spring males have the “white streaks on forehead and crown much reduced in size, sometimes obsolete, and red nuchal area more restricted, through wearing off of red tips of feathers.” The white streaks on the crown of the adult female also wear away almost entirely during winter, leaving the crown clear black.
Food.—The food of Nuttall’s woodpecker is very similar to that of the downy and other small woodpeckers. Prof. F. E. L. Beal (1911) summarizes it by saying: “In its animal food the Nuttall woodpecker is beyond criticism. Practically all of the insects eaten are either pests or of no positive benefit. While some fruit is eaten, it consists largely, and perhaps entirely, of wild varieties. Probably the worst that can be said of the bird is that it helps in the distribution of poison-oak seeds.”
Among the insect food, the most prominent items seem to be the larvae of the very harmful wood-boring beetles Cerambycidae and Elateridae; other beetles are eaten largely, as well as ants and other Hymenoptera, scales, plant lice and other bugs, weevils, caterpillars, spiders, flies, and millipeds. Prof. Beal (1911) says: “Two stomachs contained each between 30 and 40 box-elder bugs (Leptocoris trivittatus). These insects have a way of becoming very abundant at times and making a nuisance of themselves by invading buildings in search of winter quarters.”
The vegetable food consists mainly of wild fruits, such as blackberries, elderberries, and the seeds of poison-oaks; a few acorns and some grain are occasionally eaten. Grinnell, Dixon, and Linsdale (1930) write: “Trees that this woodpecker foraged over were sycamore, cotton, valley oak, blue oak (most frequently), digger pine, yellow pine (rarely), and orchard trees. On June 3, 1926, one was seen feeding on cherries in an orchard near Manton.”
Behavior.—Florence M. Bailey (1902) says of this little woodpecker:
It has a nuthatch-like way of flying up to light on the underside of a limb, and when hanging upside down turns itself around with as much ease as a fly on a ceiling. * * *
He is a sturdy little fellow, and in flight will sometimes rise high in air and fly long and steadily, dipping only slightly over the brush. He has the full strength of his convictions and will drive a big flicker from a sycamore and then stretch up on a branch and call out triumphantly. Two Nuttalls trying to decide whether to fight are an amusing sight. They shake their feathers and scold and dance about as if they were aching to fly at each other, but couldn’t quite make up their minds to so grave a matter.
Voice.—The same writer says of the voice of Nuttall’s woodpecker: “At times the small Nuttall waxes excited, and shakes his wings as he gives his thin, rattling call. All his notes are thin, and his quee-quee-quee-quee’p has a sharp quality. His chit’ tah is a diminutive of the ja’ cob of the California woodpecker.”
Ralph Hoffmann (1927) says: “One cannot remain long near a grove of live oaks in the foothills of California without hearing from some tree a hoarse ringing call prrip, often lengthened to a rattling prrrrrrt. It has the exclamatory quality of the Hairy Woodpecker’s, but is less clear and metallic, with more burr. * * * Like the other woodpeckers the Nuttall, particularly in spring, drums on resonant timber or telephone poles; it also gives at that season a rapid, squealing quee quee quee quee.”
Mr. Dawson (1923) says that this woodpecker “always has a grouch on, and you are sure to be challenged as you pass, by repetition of his double notes of distrust, ticket, ticket—ticket it.”