Eggs.—The eggs of Gairdner’s woodpecker resemble those of the northern downy (medianus) in every respect but average slightly smaller. The measurements of 34 eggs average 18.71 by 14.51 millimeters; the eggs showing the four extremes measure 20.83 by 15.24, 20.32 by 16.0, 17.27 by 14.22, and 17.78 by 12.95 millimeters.
Food.—Johnson A. Neff (1928) had 68 stomachs available for study, mostly Gairdner’s woodpeckers from the Willamette Valley, Oreg., and states that—
the animal food items averaged 82.07 percent of the annual food, and vegetable matter, 17.93 percent. * * *
At Peyton, in August, the Gairdner Woodpeckers were observed working busily for several days removing the larvae, pupae, and adults of weevils from the stems of common mullen, Verbascum thapsus. * * *
During July, 1925, whole families of the Gairdner Woodpecker were observed in the huge cottonwoods which abound near the Willamette River, feeding on aphids and scale. They often numbered as high as ten birds in one tree, and worked from the lowest limb to the highest leaf. While paying some attention to the branches, their chief interest was in the clusters of leaves; they clambered out each small branch to the group of leaves at the tip, peered under each leaf intently, even swinging around sidewise and up-side down in their efforts. Through the binoculars it was easy to see them remove small objects and, later, stomach analysis showed that most of the objects were scale insects. * * *
These woodpeckers have yet to be observed doing any injury to a living tree; the writer has been unable to find any evidence of their doing so in this area. While they nested abundantly in the river-bottom lands in very close companionship with true sapsuckers, they were never seen to visit the flowing sap pits. * * *
Fruit was hardly touched by these birds; elderberry (Sambucus) and Madrona (Arbutus) were the only kinds found, averaging only 0.46 percent of the diet. * * *
The Gairdner, Willow, and Batchelder Woodpeckers in the orchard are worth their weight in gold to the fruit grower. They should be strictly protected, and every known means of attraction should be used in the attempt to persuade them to remain about the ranches.
Winter.—Anderson and Grinnell (1903) say that, in the Siskiyou Mountains, Calif., “the Gairdner woodpecker is usually to be found in company with the flocks of mountain chickadees which frequent the black oak groves all winter. The oaks are their favorite working places, but they are also to be seen among the pines and spruces. Six specimens brought home are all quite near gairdneri. The smokiness of the lower surface is not so intense as in skins from western Oregon, but the size, especially of the feet, is decidedly that of the northwest coast form.”