Range.--Pacific coast from California to Alaska. The habits and eggs of this slightly darker variety are just the same as those of the common Chickadee of the east. 736. CAROLINA CHICKADEE. _Penthestes carolinensis carolinensis._ Range.--Southern United States from the Gulf to New Jersey and Illinois. The southern Chickadee is smaller than the northern and the wing coverts and feathers have little or no white edgings. Their nesting habits are in every particular the same as those of _atricapillus_ and the eggs cannot be distinguished with certainty, but average smaller; size .53 × .43. 736a. PLUMBEOUS CHICKADEE. _Penthestes carolinensis agilis._ Range.--Eastern and central Texas. This variety is said to be more plumbeous above and much whiter below than the preceding. No differences can be found in the eggs of the two varieties and the nesting habits are the same. 737. MEXICAN CHICKADEE. _Penthestes sclateri._ Range.--Mountains of western Mexico north to southern Arizona. This species has the black more extended on the throat and the under parts are grayish of a lighter shade than the upper, the cheeks, however, remaining white. Their nests are in hollow stubs and the eggs are indistinguishable from those of the foregoing Chickadees. 738. MOUNTAIN CHICKADEE. _Penthestes gambeli gambeli._ Range.--Rocky Mountain region and west to the Pacific; north to British Columbia chiefly in higher ranges. This handsome little Titmouse has a white superciliary line, leaving a black stripe through the eye. Their habits are like those of the other Chickadees and they are equally confiding and inquisitive. Their eggs range from five to eight in number and are either pure white or faintly marked with reddish brown; size .60 × .45. Data.--Estes Park, Colorado, June 8, 1803. Nest in an old Sapsucker's hole in a live aspen tree, 28 feet from the ground; cavity lined with hair and fur. [Illustration 437: 735b--737--738.] [Illustration: White.] [Illustration: White.] [Illustration: right hand margin.] Page 436 739. ALASKA CHICKADEE. _Penthestes cinctus alascensis._ Range.--Northern Alaska and eastern Siberia. This bird, which is most like the Hudsonian Chickadee, nests in the usual manner and its eggs are like those of the common Chickadee of the east. 740. HUDSONIAN CHICKADEE. _Penthestes hudsonicus hudsonicus._ Range.--Western half of British America. These brown capped Chickadees are very abundant throughout the northwest and are even tamer than our United States varieties. They usually make their nests at low elevations in dead and decayed stumps and line the bottom of the cavity, which varies from three to eight inches in depth, with moss and fur. Their eggs, which they lay in May, June or July, are white, specked with reddish brown and cannot with any certainty be distinguished from those of the Black-capped Chickadees, the eggs of all the species showing considerable variations; size .60 × .45.