_Voice._--Dr. Lewis (MS.) records the common cry of this woodpecker as “_tchuk_, often shortened and sharpened to _kip_.” He also says: “A male mounted a stub, about 25 feet from me, and there, in plain view, scolded me vigorously with a sharp note like _kuk_, repeated about once a second for some minutes. Each time the note was uttered there was a flash of whitish at the bird’s eye, as though it winked with each utterance. It was also heard to utter a rattling note, apparently another kind of scolding cry.” Francis H. Allen tells me that the “call-note resembles the _cluck_ used in New England to start a horse; it has a ‘woodeny’ quality.” Ralph Hoffmann (1927) says that “in the breeding season the Arctic Three-toed Woodpecker makes a very loud rolling sound by drumming on dry limbs and when concerned about the nest a shrill _kick-er-uck-a-kick_. The ordinary call is _tschick_ or _tschuck_.” A note of greeting, possibly part of a love-making performance, is thus described by Mr. Achilles (1906): “Several times when the female was getting grubs in the dead spruce near the hole, the male would fly from some distant tree and alight near her. She would see him coming and, just about as he was about to alight, would spread her wings and utter a ‘whe-e-e-e-ee.’ This call, which was its loudest at its middle point, rose and then fell to the same pitch at which it was begun.” Rev. C. W. G. Eifrig (1906) heard a queer sound that “was as if produced by pulling out the end of a clock spring and suddenly releasing it, producing a wiry, humming sound. The author of it proved to be a male of this woodpecker. In the course of the half hour that I watched him he showed himself master of quite a repertoire of notes and would-be songs. When flying he would say: _chut chut_ and then rattle like a Kingfisher. When hammering on a tree and preening himself, he would intersperse those actions by chuckling: _duck, duck, duck_.” _Field marks._--All the three-toed woodpeckers can be easily recognized by the yellow patch on the crown of the adult male and by more or less yellow in the crowns or young birds of both sexes. The crown patch of the adult male _arcticus_ is larger and extends farther forward than that of _tridactylus_. But the best field mark for the Arctic three-toed woodpecker is the solid-black back, without any white markings, and in the female the solid-black crown as well; the dorsal aspect, when the bird is clinging to a tree trunk, often appears wholly black. The white stripe on the side of the head, below the eye, is much wider in _arcticus_ than in _tridactylus_, and the latter has the back transversely banded with white. _Enemies._--Mr. Achilles (1906) relates the following: