ALPINE THREE-TOED WOODPECKER
HABITS
This race of the three-toed woodpeckers enjoys the most southern distribution of any of the birds of this genus, ranging from northern Montana to northern Arizona and New Mexico, in the boreal forests of the Rocky Mountains. Ridgway (1914) characterizes it as “similar to white-backed examples of P. a. fasciatus, but larger; white markings on back usually all longitudinal (very rarely with any transverse bars of black), white supra-auricular streak usually broader, forehead usually with more black and less whitish spotting, white spots or bars on inner web of innermost secondaries larger, and sides and flanks usually less barred with black.”
The Weydemeyers (1928) say that in northwestern Montana, “unlike arcticus, this species prefers dense, virgin forests to cut-over woods and open woodland pastures. * * * In the higher elevations, this woodpecker may be found in white pine, lodgepole pine, alpine fir, and Engelmann spruce forests. In the Transition zone, it shows a preference for spruce woods, with larch and yellow pine forests as second choice. In the Canadian zone, this species is somewhat commoner than arcticus; in the Transition zone, it occurs only about one-third as frequently as does the larger bird.”
M. P. Skinner says, in his Yellowstone National Park notes: “This woodpecker is rather uncommon, but I have seen it in coniferous forests between 6,500 and 8,000 feet, in firs, lodgepole pine, and Engelmann spruce. I have also seen it on dead trees and on telephone poles. I have seen this woodpecker in this Park only between May and October.”
Nesting.—At an altitude of about 9,000 feet in the mountains of Colorado, in or near Estes Park, John H. Flanagan (1911) collected a set of four eggs of the alpine three-toed woodpecker. “The hole was in an aspen stub, nine feet from the ground and about a foot or eighteen inches from the top, and just before the guide reached the hole the bird flew out. * * *
“The entrance to the nesting cavity was about one and one-half inches in diameter; the cavity itself about nine or ten inches in depth and quite large at the bottom. The eggs were laid on a few chips.”
In north-central Colorado, Edwin R. Warren (1912) found a nest of this woodpecker “in a dead Engelmann spruce, which was twenty-five inches in diameter at the base, and twenty at the nest hole, the latter being seven feet above ground. The nest was eight inches deep, the entrance one and three-quarters inches in diameter; the thickness of the wood on the front side of the hole was two and three-quarters inches, and the cavity was five inches from front to back, and three wide. There were a few chips in the bottom, as well as a few of the birds’ droppings. There were two young, about ready to fly, though I had no difficulty in posing them on the tree for pictures; they showed little or no fear.”
Randolph Jenks (1934) discovered two nests of the alpine three-toed woodpecker on the Kaibab Plateau, near the east rim of the Grand Canyon, in northern Arizona. One was in “a hole in an aspen tree, two and one-half inches in diameter, opening to the southeast, twelve feet from the ground. The cavity was eight inches deep and the nest was lined with a thick layer of maggot-infested sawdust. In spite of the crawling competitors, the nestlings, a male and a female, seemed quite contented.” This was on June 30, 1931. Several days later another nest was found, also on the Plateau, at an elevation of 8,100 feet; this nest was “in a hole about sixty feet above the ground in a western yellow pine.”
Dr. Edgar A. Mearns (1890b) writes:
The Alpine Three-toed Woodpecker breeds commonly throughout the pine belt, seldom ascending far into the spruce woods of the highest peaks [in the mountains of Arizona]. On the northwestern slope of San Francisco Mountain I discovered a nest of this species on June 8, 1887. The female was seen alone pecking at a large yellow pine, which, although dead, still retained its bark and was quite solid. While feeding she uttered a peculiar, harsh, nasal cry. I shot her, and then noticed a small, neatly bored hole in the south side of the pine trunk, about 30 feet from the ground and away from branches. With the aid of a rope, and taking a start from the saddle, I was scarcely able to climb to the nest, which the male did not quit until I was well up; then he came out and uttered a sudden, sharp “whip-whip-whip” in a menacing tone, remaining hard by while I worked with saw and chisel. It took me nearly half an hour to make an opening sufficiently large to admit the hand, as the burrow was situated so extraordinarily deep. Two young, male and female, with feathers just sprouting, were found on a bed of small chips at the bottom of the burrow, not more than 8 inches lower than the entrance, but in the very heart of the tree, the cavity being oblique and pear-shaped, and having the strong odor characteristic of Woodpeckers’ nests in general. Both parents and their progeny were preserved, and are now in the American Museum collection. The irides of the adults were dark cherry red; their feet, claws, and basal half of mandible plumbeous, the rest of the bill being plumbeous black.
Eggs.—The alpine three-toed woodpecker is said to lay five eggs to a set, but probably the set oftener consists of fewer eggs. I have seen no eggs of this subspecies; and the only measurements I have been able to get are those from a set of five eggs, collected by A. Treganza in Salt Lake County, Utah, on June 3, 1916; these are in the P. B. Philipp collection in the American Museum of Natural History. The measurements average 24.52 by 17.52 millimeters, rather large for the species; the eggs showing the four extremes measure 25.3 by 17.7 and 24.1 by 17.4 millimeters.
Food.—Mrs. Bailey (1928) says that the food of this woodpecker consists of “over 75 percent, destructive wood-boring larvae of caterpillars and beetles. The Three-toed Woodpeckers rank high as conservators of the forest, eliminating annually, as Professor Beal has estimated, some 13,675 of the grubs most destructive to forests. The scarcity of these useful woodpeckers makes their protection and encouragement especially important.”