During the winter months when sap is practically at a standstill in the coniferous trees at high altitudes, the Williamson Sapsucker must needs seek other fare. A few of our own observations added to those of other naturalists suggest that during the winter season the birds may forage in a large part on dormant insects or on insect larvae hidden in crevices in the bark. If such is the case, whatever the damage done by these birds to the forest as a whole during the summer months, it is partially offset by their wintertime activity. In any event, the attacks of the Williamson Sapsucker on the lodgepole pines of the central Sierra Nevada cannot be considered as of great economic importance, for these trees are there used little if at all for lumber or for any other commercial purpose. _Behavior._--Dr. J. C. Merrill (1888), at Fort Klamath, Oreg., found this sapsucker “shy and very suspicious. A noticeable habit here is the frequency with which it works down as well as up a trunk, and when one dodges around a tree, in which, by the way, it is unpleasantly expert, it is as apt to reappear twenty feet below where it was last seen, as above. In searching for food it will often work up and down a favorite tree repeatedly. In all its movements it is quick and active, and gives one the impression of being thoroughly wide awake, which impression the would-be collector is speedily convinced is correct.” _Voice._--Mr. Michael (1935) says: “When the sapsuckers met at the nest site they exchanged greetings in a ‘rubber doll’ tone of voice. The nasal quaver of notes was remindful of a call often sounded by the red-breasted sapsucker. Another call that was occasionally shouted from the tree-tops was shrill and like that of a red-tailed hawk.” Dr. Elliott Coues (1874) says: “It has an abrupt, explosive outcry, much like that of other species of Woodpeckers, and also an entirely different call note. This sounds to me like a number of rolling _r’s_, beginning with a gutteral _k--k’-r-r-r_--each set of _r’s_ making a long syllable. This note is leisurely given, and indefinitely repeated, in a very low key.” Grinnell and Storer (1924) describe the voice as “a weak wheezy _whang_ or _whether_.” _Field marks._--Such a conspicuously and uniquely colored woodpecker as the male Williamson’s sapsucker should be easily recognized; its general appearance is largely black, with a large white patch in the fore part of the wing, and another on the rump and upper tail coverts; the yellow on the under parts is not so easily seen; neither is the red throat. The female appears mainly pale brown, with a white rump, brown head, and barred back and wings. DISTRIBUTION _Range._--Mountainous regions of the Western United States and southwestern Canada south to west-central Mexico.