The hole, which was in a spruce tree, faced north by northeast, and was twenty-seven feet one inch from the ground. The spruce retained all its branches and some twigs, although it had been dead for some time.
The following dimensions of the hole were taken after the young had left their nest. The entrance to the hole was two inches wide and one and five-eighths inches high. From the outside of the hole, straight through over the top of the nest to the back of the hole, the measurement was five and three-fourths inches. The outside shell, including the bark, was one and three-fourths inches thick. The diameter of the nest opening was three and one-fourth inches, while the diameter of the hole on the inside at the bottom of the shaft, was four and five-eighths inches. The depth of the hole was nine and one-eighth inches.
Dr. C. Hart Merriam sent Major Bendire (1895) some notes on two nests that he found in the Adirondacks, as follows:
The water of Seventh Lake, Fulton Chain, had been raised by a dam at the foot of Sixth Lake, flooding a considerable area along the inlet, and the trees killed by the overflow stood in about 6 feet of water. In 1883 the place was first visited by me, May 27. Both species of Three-toed Woodpeckers (Picoides americanus and arcticus) were tolerably common, and one new nest of each was found. That of P. arcticus contained one fresh egg. The nest was 10 inches deep, and the opening within 5 feet of the surface of the water. It was in a dead spruce, 10 inches in diameter. * * * The place was next visited, June 2, but the date proved still too early. Several unfinished nests of P. americanus were found, and one completed nest with four fresh eggs of P. arcticus. Like the one found on my first visit, it was in a dead spruce and about 5 feet above the water. The nest was 11 inches deep and the orifice 1¾ inches in diameter.
J. H. Fleming (1901) says that the Arctic three-toed woodpecker is “a common resident in Parry Sound, rarer in Muskoka. This Woodpecker has a habit of sometimes nesting in colonies. I saw the nests of such a colony near Sand Lake in 1896; there were six or seven nests, each cut into the trunk of a living cedar, just below the first branch, and usually eight or ten feet from the ground. The cedars were in a dense forest, overlooking a small stream that empties into Sand Lake.”
Macoun (1909) reports, on the authority of Spreadborough, that “a pair nested in a telegraph pole quite near Cache lake station of the Parry Sound railway.” Major Bendire (1895) writes:
On May 10, 1883, while en route from Fort Klamath to Linkville, Oregon, and only a few miles from the latter place, just where the pine timber ended and the sagebrush commenced, I found a male busily at work on a pine stump, only about 2½ feet high and about 18 inches in diameter, standing within a few feet of the road, and close to a charcoal burner’s camp, in quite an open and exposed situation, nearly all the timber in the vicinity having been cut down. The stump was solid, full of pitch, and showed no signs of decay; the entrance hole was about 1½ inches in diameter and 8 inches from the top. The cavity, when first examined, was only about 2 inches deep, and on my return, two days later, it had reached a depth of 4 inches: the female was then at work. To make sure of a full set of eggs, I waited until the 25th. The cavity then was found to be 18 inches deep, and was gradually enlarged toward the bottom. The four eggs it contained had been incubated about four days. The female was on the nest, and uttered a hissing sound as she left it, and might easily have been caught, as she remained in the hole until the stump was struck with a hatchet. The sides of the cavity were quite smooth, and the eggs were partly embedded in a slight layer of pine chips. The locality where this nest was found was near the top of a low divide, not over 4,100 feet in altitude.
Dr. Thomas S. Roberts (1932) calls attention to an interesting feature in the nesting habits of this woodpecker, as observed in two nestings that he saw in Minnesota; he says of the two nests:
The nesting-hole was in a live jack-pine on the edge of a tamarack and spruce swamp, only twenty feet from a traveled road and close by a log house used as a store. The entrance faced south and was twelve feet from the ground, at which point the tree was seven inches in diameter. The outer bark of the tree had been chipped off for a distance of twelve to fifteen inches above and below the hole and half-way around the tree, thus leaving a large, irregular, whitish area. * * *
Another nest, found the same season, was also in a live evergreen tree and the outer bark had been similarly stripped from around the entrance, making a conspicuous, white patch with the dark nesting-hole in the center. Can this be a direction mark for the returning bird among the dark tree trunks around?