The Chestnut-backed Chickadees 
of a fortnight I started to my feet thinking I heard the song of the 
Sierra Hermit Thrush—only to find that it was a nearer Chickadee who 
had stolen his voice and accent. This type of song was constant, so 
far as observation went, and may possibly serve to distinguish a sep¬ 
arate race of Mountain Chickadee in the San Jacintos. 
No. 124 
Chestnut-backed Chickadee 
A. 0 . U. No. 741. Penthestes rufescens rufescens (J. K. Townsend). 
Synonym.— Chestnut-sided Chickadee. 
Description. — Adults: Crown and nape dull sepia brown, becoming sooty 
toward lateral border—black before and behind eye, separated from sooty black 
throat-patch by large white area, broadening posteriorly on sides of neck; back, scapu¬ 
lars, rump, and sides of body bright chestnut (nearer auburn); lesser wing-coverts 
grayish brown; upper tail-coverts hair-brown or more or less tinged with chestnut; 
wings and tail deeper grayish brown, edged with paler gray; remaining upperparts 
(centrally) white; under tail-coverts washed with brownish. Bill black; feet brownish 
dusky; iris brown. The brown of crown and hind-neck deepens in winter. Young 
birds are duller in coloration, especially as to the chestnut of back and sides. Length 
about 120.6 (4.75); wing 60 (2.35); tail 48.3 (1.90); bill 9.5 (.37); tarsus 16.5 (.65). 
Recognition Marks. —Pygmy size; chestnut of back and sides distinctive— 
otherwise not easily distinguished in the treetops from P. a. occidentalis. Frequents 
thicker timber, and usually drier situations. 
Nesting. — Nest: In hole in dead stub, usually some natural cavity enlarged, 
and customarily at moderate heights, 10-20 feet; a couch of fine bark-shreds, green 
moss, etc.; heavily felted with squirrel-, rabbit-, or cow-hair, and other soft sub¬ 
stances. Eggs: In California 5 or 6; 9 of record in the North; pure white as to ground, 
and sparingly sprinkled with reddish brown dots (sayal brown to snuff-brown), chiefly 
about larger end. Av. of 47 eggs from Eureka, 15.2 x 11.7 (.60 x .46). Season: April 25 
-June 15 (according to altitude); one brood. 
Range of Penthestes rufescens. —Pacific Coast district of North America from 
Prince William Sound, Alaska, south to Monterey County, California. 
Range of P. r. rufescens. —The Pacific Coast district from southeastern Alaska, 
south to Sonoma County, California; east (centrally) to western Montana. 
Distribution in California. —Common resident in Canadian and Transition 
zones of the northwest humid coastal region, east regularly to the Siskiyou Mountains, 
casually to west base of Mt. Shasta, south on coast to Freestone, in Sonoma County, and 
interiorly to Mount Saint Helena. 
Authorities.—Audubon (Parus rufescens), Birds of America, vol. ii ., 1841, 
p. 158 (Upper California); Fisher, Condor, vol. iv., 1902, p. 135 (redwood belt of 
Humboldt and Del Norte counties); Grinnell, Auk, vol. xxi., 1904, p. 364, 3 maps 
(origin, distr., etc.); Beal, U. S. Dept. Agric., Biol. Surv. Bull. no. 30, 1907, p. 70 
(food); Bowles, Condor, vol. xi., 1909, p. 55 (nesting habits, etc.; in Washington). 
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