THE CHESTNUT-BACKED CHICKADEE. _ 281 
feature of the interior construction was a knot, which had persisted as a hard 
core when the surrounding punk had been removed. This had evidently been 
no end of amusement to the young birds and of service to the parents as well, 
for its surface was polished by the friction of many Penthestine 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 border—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; wings 
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 hind-neck deepens in 
winter. Young birds are duller in coloration, especially as to the chestnut of back 
and sides. Length about 4.75 (120.6) ; wing 2.35 (60) ; tail 1.90 (48.3) ; bill .37 
(9.5); tarsus .65 (16.5). 
Recognition Marks.—Pyegmy size; chestnut of back and sides distinctive 
otherwise not easily distinguished in the tree-tops from P. a. occidentalis. 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 xX .47 (15.5 X II.Q). 
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 Lynn 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, Journ. Ac. Nat. Sci. Phila. VII. 
ie 7a OOwe ee Gkan bt. Rh Kb, Ra. iB. E. 
Specimens.—U. of W. P. Prov. B. E. 
WHAT busy little midgets these are as they go trooping thru the tree- 
tops intent on plunder! And what a merry war they wage on beetle and nit 
as they scrutinize every crevice of bark and bract! The bird eats insects at 
