The Arizona woodpecker commences to moult about the middle of July, and by the first week in September the new plumage is almost completely acquired. The plumage of the breast, abdomen, and lower parts generally, seems to be the first to be renewed, while the remiges, rectrices and feathers of the interscapular region are the last to get their growth. An old female shot on September 3 had practically completed its moult, with the exception of the tail feathers, none of which were over half an inch long; while several specimens of both sexes, taken during the last two weeks in August, are in nearly perfect autumnal plumage, except for some small patches of old feathers in the interscapular region. Fall specimens are considerably darker on the back than birds taken during the spring and summer, but the change is undoubtedly due to fading of the plumage, as birds taken in the late winter and early spring, show not the slightest traces of moult, and a series of birds taken from February to July, show plainly the gradual change of coloration. Singularly enough the pileum and back of the neck does not seem to fade as the dorsum does, and consequently, while birds in fresh fall plumage are of practically uniform coloration on the upper parts, specimens taken in the late spring and summer have the head and neck abruptly darker than the back and exposed portion of the wings. * * * Of twenty-four specimens from this region [Arizona] four show more or less traces of white bars across the rump; one of these is a male in nuptial plumage, one a male in freshly acquired autumnal plumage, one a female in nuptial plumage (this specimen has some faint indications of white bars on some of the scapulars as well), and one is a young male. Another spring female has some white bars on the scapulars but none on the rump. Presumably this is a tendency toward the Mexican species Dryobates stricklandi.
Food.—Very little seems to be recorded on the food of the Arizona woodpecker, which probably does not differ greatly from that of other members of the Dryobates group. It apparently feeds mainly on insects and their larvae, but to some extent on fruits and acorns. Mr. Henshaw (1875) says of its feeding habits: “When in pursuit of food, they almost always alighted near the base of the trees, gradually ascending, and making their way along the smaller limbs, and even out among the foliage, appearing to prefer to secure their food by a careful search rather than by the hard labor of cutting into the wood in the way the hairy woodpecker employs its strength.”
Behavior.—The same observer says of their habits:
Here they appeared to be perfectly at home, climbing over the trunks of the oaks with the same ease and rapidity of movement that distinguish the motions of the downy or hairy woodpecker; though their habits, in so far as they are at all peculiar, are, perhaps, best comparable to those of the red-cockaded woodpecker of the South (P. borealis), especially their custom of moving about in small companies of from five to fifteen, though they were occasionally found singly or in pairs. * * *
I found them at all times rather shy, and gifted with very little of that prying curiosity which is seen in some of the better known species of this family; and if by chance I surprised a band feeding among the low trees, a sharp warning note, from some member more watchful than the rest, communicated alarm to the whole assembly, when they took flight immediately, showing great dexterity in dodging behind trunks and limbs, and making good their retreat by short flights from one tree to another till they were out of sight.
In the Whetstone Mountains, Ariz., Austin Paul Smith (1908) observed a female Arizona woodpecker—
working on an oak-trunk, not three feet above the base; while the trees around harbored unnumbered Bridled Tits (Baeolophus wollweberi), Lead-colored Bush-tits (Psaltriparus plumbeus) and Rocky Mountain Nuthatches (Sitta carolinensis nelsoni). Very often did I run across a similar assemblage, but rarely were there more than one or two Arizona Woodpeckers in it. There is no recollection at hand, of noting above four adult woodpeckers of this species in view at once; more likely to chance upon a solitary individual than a pair at any time. The noisiest occasion I can accredit to the species occurred one spring day when two adult females were located, perched upon a horizontal limb of a madrona, facing each other, and emitting a continuous volume of characteristic woodpecker notes, the effect being heightened by that peculiar muscular movement which accompanies the vocal utterances of some Pici. The continuity was possible by a relay system; and so engrossed were the participants, that I approached to directly under the limb and stood there at least two minutes, without being detected.
F. H. Fowler (1903) writes:
The Arizona woodpecker (Dryobates arizonae) is, outside of the alpine three-toed and pileated, the most interesting member of the woodpecker family, that I have ever seen. So far as I have noted, the species is never common, never noisy, and never at rest. I have not found it except in live-oak woods, and at Fort Huachuca; on a good field day I used to see about six on an average. Not even the chickadees are as active as this little woodpecker. He will alight on the main trunk of the tree, or generally one of the largest limbs, and the moment his claws are fastened in the bark he begins an untiring search for insects and grubs. He ascends rapidly in spirals picking and prying away small pieces of bark in search of food; when a promising limb is reached out he goes on it, often on the lower side. The search over in one tree, he wastes no time in looking around, but launches out, with barely a glance to determine the course, in his undulating flight to the next, there to repeat the performance. When closely approached, he works around the tree without paying any especial attention to the intruder, and when thoroughly frightened he will take flight with as little warning as he does when simply in search of food. While going up the tree he gives, from time to time, a characteristic call, much like that of the hairy woodpecker.
Field marks.—The Arizona woodpecker should be easily recognized, as it is the only small woodpecker that has a uniformly brown, unmarked back and crown, and lower parts thickly spotted with black; the adult male has a red patch on the nape, and young birds of both sexes have more or less red in the crown, less in the female than in the male.