Dr. Cooper found them throughout the year near San Francisco. He found one of their nests at San Diego as early as the first of March. The nest is so large, compared with the size of the birds, as to suggest the idea that the flock unite to build it. He gives the measurements as eight inches in length and three in diameter, outside; the cavity five inches long, one and a half in diameter. It was cylindrical, and suspended by one end from a low branch.
When one of these birds is killed, Dr. Cooper says that the others come round it with great show of anxiety, and call plaintively until they find it will not follow them, becoming so fearless as almost to allow of their being taken by the hand.
Psaltriparus minimus, var. plumbeus, Baird.
LEAD-COLORED BUSH-TITMOUSE.
Psaltria plumbea, Baird, Pr. A. N. S. VII, June, 1854, 118 (Little Colorado). Psaltriparus plumbeus, Baird, Birds N. Am. 1858, 398, pl. xxxiii, fig. 2; Review, 84.—Sclater, Catal. 1861, 398, No. 77.—Cooper, Birds Cal. 1, 49.
Sp. Char. Tail long, feathers graduated. Above rather light olivaceous-cinereous. Top of head rather clearer; forehead, chin, and sides of head, pale smoky-brown. Beneath brownish-white, scarcely darker on the sides. Length about 4.20 inches; wing, 2.15; tail, 2.50.
Hab. Southern Rocky Mountain region of United States, from mountains of West Arizona to Green River, Wyoming; west to Carson City, Nevada (Ridgway).
This variety is very similar to the Psaltriparus minimus of the west coast, which it represents in the Rocky Mountain region. It is, however, appreciably larger, the wings and tail proportionally longer. The top of the head is plumbeous, uniform with the back, instead of smoky-brown. The back is a paler ash, the under parts darker.
Habits. Of the history of this variety but little is known. It is found in the southern portion of the Rocky Mountain regions, within the United States, in Arizona and New Mexico. The extent of its area of distribution remains to be ascertained. Dr. Kennerly met with it on Little Colorado River, where he observed it among the scattered bushes along the banks of the river, occurring in large flocks. These passed rapidly from place to place, uttering their short, quick notes. He afterward met with them along the head waters of Bill Williams Fork, inhabiting the tops of the cotton-wood trees. When attracted to them by their notes, they could only be seen after a very careful search. He obtained no knowledge as to their mode of nesting, and no information, so far as we are aware, has been obtained in regard to their eggs. It may, however, be safely conjectured that they are white, and hardly distinguishable from those of the minimus. Dr. Coues found them common near Fort Whipple, Arizona.
Mr. Ridgway met with this bird in especial abundance among the cañons of West Humboldt Mountains in September. He found it also in all suitable places westward to the very base of the Sierra Nevada Mountains. It was met with principally in the thick brushwood bordering the streams, in ever-restless companies, continually twittering as they flew from bush to bush, in single rows. Mr. Ridgway describes these birds as remarkably active in their movements. If unmolested, they were exceedingly unsuspicious and familiar. During November he found them inhabiting the cedars, always associating in scattered flocks.