HABITS. The Chestnut-backed Titmouse was first obtained by Townsend on the banks of the Columbia River, and described in the Journal of the Philadelphia Academy. It is a resident, throughout the year, of the forests of the Columbia, and is found throughout California. Like all of this familiar family, they may be seen in small flocks, of all ages, in the autumn and winter, moving briskly about, uttering a number of feeble querulous notes, after the manner of the _atricapillus_, but never joining in anything like the quaint and jingling song of that bird. They occasionally have a confused warbling chatter. These busy little groups may be often seen in company with the _Parus occidentalis_ and the _Regulus satrapa_, moving through the bushes and thickets, carefully collecting insects, their larvæ and eggs, for a few moments, and then flying off for some other place. They are supposed to rear their young in the midst of the densest forests. Mr. Nuttall states that when the gun thins their ranks the survivors display surprising courage and solicitude, following their destroyer with wailing cries, entreating for their companions. Dr. Gambel found the young of this species in great abundance around Monterey in the fall and winter months. Dr. Heermann saw them in June, 1852, feeding their young in the vicinity of San Francisco, where, however, they are rare. In Washington Territory, Dr. Cooper found this the most abundant species. It preferred the dense evergreens, where large parties could be found at all seasons busily seeking food among the leaves and branches, ascending even to the highest tops. They were usually in company with the _Reguli_ and the other Titmice. Mr. Bischoff found them abundant at Sitka. They nest, like all the others of this genus, in holes in soft decayed trunks and large limbs of trees a few feet from the ground. Their eggs are not as yet known. Parus hudsonicus, FORST. HUDSON’S BAY CHICKADEE; BROWN-CAPPED CHICKADEE. _Parus hudsonicus_, FORSTER, Philos. Trans. LXII, 1772, 383, 430.— AUD. Orn. Biog. II, 1834, 543, pl. cxciv.—IB. Birds Am. II, 1841, 155, pl. cxxviii.—BAIRD, Birds N. Am. 1858, 395; Review, 82.—SAMUELS, 185.—DALL & BANNISTER (Alaska). _Parus hudsonicus_ var. _littoralis_, BRYANT, Pr. Bost. Soc. N. H. IX. 1863, 368. SP. CHAR. Above yellowish olivaceous-brown; top of head purer brown, not very different in tint. Chin and throat dark sooty-brown. Sides of head white. Beneath white; sides and anal region light brownish-chestnut. No whitish on wings or tail. Tail nearly even, or slightly emarginate and rounded. Lateral feathers about .20 shortest. Length about 5 inches; wing, 2.40; tail, 2.66. HAB. Northern portions of North America, from Atlantic to Pacific. Specimens from the most northern localities appear larger than those from Maine and Nova Scotia (_P. littoralis_, BRYANT), with proportionally longer tails (3.00 inches, instead of 2.40). We can, however, detect no other difference.