THE CHESTNUT-BACKED CHICKADEE. 281 



feature ui the interior constructidii was a km it, which had persisted as a hard 

 core when the surnjunding punk had been removed. This had evidently been 

 no end of amusement to tiie }-oung birds and of service to tlie parents as well, 

 for its surface was polished by the friction of many Pentliestine toes. 



No. 109. 



CHESTNUT-BACKED CHICKADEE. 



A. O. U. No. 741. Penthestes rufescens Towns. 



Description. — Adults: Crown and nape dull sepia brown becoming sooty 

 toward lateral Ixirder — black before and behind eye. separated from sooty black 

 throat patch by large white area broadening posteriorly on sides of neck; back, 

 scapulars, rump, and sides of body rich chestnut ; lesser wing-coverts grayish 

 brown; upper tail-coverts hair-brown or more or less tinged with chestnut; wmgs 

 and tail deeper grayish brown edged with paler gray ; remaining underparts 

 (centrally) white; under tail-coverts washed with brownish; bill black; feet 

 brownish dusky; iris brown. The brown of crown and hmd-neck deepens in 

 winter. Young birds are duller in coloration, especially as to the chestnut of back 

 and sides. Length about 4.75 ( i20.h) ; wing 2.35 (60) ; tail 1.90 (48.3) ; bill .37 

 (9.5) ; tarsus .65 ( 16.5 ). 



Recognition Marivs. — I'ygmy size; chestnut of back and sides distinctive — 

 otherwise not easily distinguished in the tree-tojis from P. a. occidcntalis. Fre- 

 quents thicker timber and, usually, drier situations. 



Nesting. — Nest: in hole of 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 

 substances. Eggs: 7-9, pure white as to ground and sparingly sprinkled with 

 reddish brown dots, chiefly about larger end. Av. size, .61 x .47 ( 15.5 x 11.9). 

 Season: April 25-June 15 (according to altitude) ; one brood. 



General Range. — Pacific Coast district, from northern California to Alaska 

 ( Prince William Sound and head of L}'nn Canal), east to Montana. 



Range in Washington. — Resident; abundant and thoroly distributed thru 

 forests of Olympic Peninsula and Puget Sound region, decreasing in numbers 

 from Cascade divide eastward (in heavier coniferous timber only). (We have 

 no records of its occurrence east of Stehekin.) 



Authorities. — Parus rufescens Townsend, lourn. Ac. Nat. Sci. Phila. YH. 

 1837, 190. T. C&S. L'. Rh. Kb. Ra. B. E. 



Specimens.— U. of W . P. Prov. B. E. 



WHAT bus\- little midgets these are as thev go trooping thru the tree- 

 tops intent on plunder! And what a merry war they wage on beetle and nit 

 as thev scrutinize every crevice of bark and bract ! The bird eats insects at 



