PIGMY NUTHATCH. Sitta pygmaea pygmaea Vigors

Field characters.—About half size of Junco; tail short, about half length of body. Top and sides of head grayish brown; back bluish slate gray; under surface of body pale buff. (See pl. 10f). Goes about in flocks, individual birds clinging to small branches and foliage like Chickadees. Voice: An irregular series of light 'chattering' notes, sup, sup'-up, sup'-up, etc., uttered by members of a flock, especially when on the move.

Occurrence.—Rather sparse resident at middle altitudes. Recorded around rim of Yosemite Valley (Gentrys, Glacier Point, Nevada Falls, Wawona Road at Grouse Creek, Yosemite Falls trail near top), and at Bean Creek, four miles east of Coulterville; also east of mountains near Walker Lake and on Mono Craters. Lives chiefly in yellow and Jeffrey pines. In flocks except when nesting.

The Pigmy Nuthatch is much less common in the Yosemite region than the other two species of nuthatches. We saw nothing of it ourselves during the summertime. But it came to our attention several times during the fall and early winter months (September 1 to December 30), when flocks appeared in localities around the margin of the Yosemite gorge. The birds seen were foraging chiefly in coniferous trees and of these the yellow and Jeffrey pines seem to be preferred, although sugar pines and the firs were visited as well. Mr. Donald D. McLean has found the species in summer near his home (Dudley) on Smith Creek, east of Coulterville. A full-grown young bird was captured by him on Bean Creek, July 29, 1919.

The Pigmy Nuthatch is small, about the same size as the Red-breasted Nuthatch, and so of about half the size of the Slender-billed. Its color features are chiefly of a negative sort. (See pl. 10f). The head is always grayish brown with neither the white cheeks of the Slender-bill nor the white stripe over the eye of the Red-breasted Nuthatch. The under surface of the body is pale buff, appearing dull white at a distance.

Unlike its relatives, the Pigmy Nuthatch is a persistently flocking species. The bands of Pigmies seen by us in the Yosemite region were all small, the largest comprising about ten individuals and the smallest four; elsewhere larger flocks have been observed. The general behavior of a flock of these birds is suggestive of that of bush-tits. These nuthatches, clinging inverted or upright as circumstances require, work over the smaller twigs and even the foliage at the top and periphery of a tree, rather than the trunk or larger limbs. When absorbed in foraging they are usually quiet; only now and then is a note to be heard. But when the flock is moving through the tree tops, a babel of small voices is heard. These notes remind one of the contented peepings of a brood of chickens when hovered beneath a hen.