Frank C. Willard (1912) says: “I think it is their habit to dig fresh holes after raising their brood of young. These fresh holes are not occupied that year but are made use of the next year when the sap has had a chance to dry and form the hard lining which coats the inside of all the cavities. I have found but one fresh hole occupied as a nest.” Bendire (1895) also says that “most of their nesting sites are used for several years in succession; in fact, I doubt very much if a freshly excavated hole in a giant cactus is fit to nest in the same season. Both sexes assist in excavating the nesting site.”
In the heavily incrusted nest cavity in a giant cactus, the eggs lie on the bare, hard floor of the nest, there being no chips to furnish a soft bed.
In addition to the trees mentioned above, the Gila woodpecker has been found nesting more rarely in oaks and palo-verdes.
Eggs.—The Gila woodpecker lays three to five eggs, three or four being much oftener found than five. The eggs are pure white and not very glossy when fresh, but sometimes quite glossy when heavily incubated; they vary from ovate to elliptical-ovate and are sometimes quite pointed. The measurements of 52 eggs average 25.14 by 18.56 millimeters; the eggs showing the four extremes measure 27.43 by 18.80, 26.6 by 20.1, 22.86 by 17.27, and 23.9 by 16.6 millimeters.
Young.—Incubation is said to last about two weeks, and is probably shared by both parents. Mr. Gilman (1915) writes:
It is not easy to determine just what food the young in the nest are given, but insects play a prominent part, as I have seen them frequently carried to the young. Fruit is also used, as I watched one parent carry ripe Lycium berries several times to the nest; after emerging from the hole she would halt at the entrance each time and “lick her chops.” * * *
The young are fed by the parents for a long time after leaving the nest, and they are regular little beggars. One pair stayed around our house for several months, and became quite tame. They were missed during the breeding season but soon came back with three youngsters to share the good things found on the bird tables in the yard. The young, though as large as their parents, would flutter their wings and sit with open beak as though the old ones told them to “open your mouth and shut your eyes,” etc. The old ones would try to get them to eat watermelon placed on the tables, but the babies would not be shown; the parents had to put it in their mouths. They followed the parents from perch to perch, begging for food until I expected to see them chastised. The pair in question stayed with the three juvenals until they had them broken to eat for themselves, and then left. After a proper interval they came back with two more young ones, thus indicating that a second brood is sometimes raised. The abundant supply of food may have been a determining factor in the number of broods raised.
Plumages.—The nestlings are naked and blind at first but become fully clothed in the juvenal plumage before leaving the nest. The young male, in juvenal plumage, is much like the adult male, but the colors are generally paler, the head and under parts grayer, the barring on the upper parts less distinct, and the white bars are suffused with brownish buff; the red patch on the crown is smaller and often consists of only a few red feathers; and the bill is somewhat smaller and weaker. The young female is like the young male but has no red on the head. I have been unable to trace the postjuvenal molt, but young birds in the following spring are apparently like the adults. Adults have a complete postnuptial molt in August, September, and October.
Food.—Major Bendire (1895) says: “Its food consists of insects of various kinds, such as ants, beetles, grasshoppers, and larvæ, and in season largely on the sweet, fig-like fruit of the sahuaras, the giant cactus, and also, to a considerable extent, on the viscous berries of a species of mistletoe which is commonly found on most of the larger cottonwoods, oaks, and mesquite trees in these regions. These sticky, whitish-looking berries are a favorite food of many Arizona birds.”
Mr. Gilman (1915) writes: