apparently nest sites are selected indiscriminately, in dead stubs in open cleared ground or burnt barrens, and in the woods, where nests are often in dead-hearted live trees. The birds have a remarkably strong attachment for their nests, as evidenced by re-laying in nest holes from which eggs had been removed, and their disregard of the immediate presence of intruders. The male evidently performs his share of the work of incubation, as well as care of young. New nest holes are apparently dug each year, and these may not be in the immediate vicinity of nests of the previous year. The site selected tends to be low, only one nest having been noted at a height of over ten feet, while one, as noted, was as low as two feet. Entrances to nest holes are strongly beveled at the lower edge, forming a sort of “door-step,” and more or less at sides and even top. While this is true in some cases with the Northern Hairy and some other woodpecker excavations which we have examined, it has not proved so frequent or pronounced. With experience, one can usually identify the nest hole of this species with comparative certainty, by this one feature. Dr. Harrison F. Lewis watched a pair of these woodpeckers excavating their nesting hole on May 27, 1936, in some second-growth woods, chiefly spruce and fir, in Saguenay County, Quebec; he says in his notes: “The Arctic three-toed woodpeckers had a partly excavated nest cavity at a height of about 14 feet on the northwest side of a dead birch stub in a clearing. The stub was about 20 feet high and 1 foot in diameter and stood about 10 feet from the border of the clearing. The nest cavity was guarded almost continually by one bird of the pair. The bird on guard clung to the lower edge of the opening of this cavity. Nine other woodpecker-made openings, many of them only partly completed, were to be seen in the same stub.