Long-tailed Chickadee 505 
Key oF THE SPECIES. 
A. With no white superciliary streak. P. a. septentrionalis, p. 505. 
B. With a white superciliary streak. P. gambeli, p. 506, 
; 
Long-tailed Chickadee. 
Penthestes atricapillus septentrionalis. 
A.O.U. Checklist no 735a—Colorado Records—Allen 72, pp. 155, 
174 ; Aiken 72, p. 195 ; Trippe 74, p. 230 ; Henshaw 75, p. 170; Minot 
80, p. 225; Tresz 81, p. 285; Drew 81, p. 87; 85, p. 15; Allen & 
Brewster 83, p. 154; Beckham 87, p. 123; Morrison 86, p. 153; 88, 
p. 72; Kellogg 90, p. 89 ; Lowe 94, p. 270; McGregor 97, p. 37; Cooke 
97, pp. 122, 222 ; Henderson 03, p. 237 ; 09, p. 241 ; Gilman 07, p. 195 ; 
Rockwell 08, p. 179 ; Richards 08, p. 194; Hersey & Rockwell 09, p. 121. 
Description.—Adult—Crown and nape glossy black; back slaty- 
grey, becoming tinged with pale buffy on the rump and tail-coverts ; 
wings and tail dusky-slate, most of the feathers edged with white; a 
white patch on the sides of the head extending forwards to the bill ; 
below, chin and throat black, rest of the under-parts dull white, 
slightly washed with pale buffy on the flanks ; iris brown, bill black, 
legs dusky. Length 5-0; wing 2-75 ; tail 2-74 ; culmen -30 ; tarsus -70. 
The sexes are alike; in the autumn the colour is a little brighter, 
especially the buffy wash on the lower back and flanks ; the young are 
very similar to the adults. 
Distribution.—Central parts of western North America, from Alaska 
and Mackenzie to New Mexico, east to Kansas, west to Utah. In 
Colorado the Long-tailed Chickadee is a fairly common resident through- 
out the year, chiefly in the foothills and at elevations up to 9,000 feet, 
though occasionally wandering higher ; in winter they are mostly below 
8,000 feet, while in summer they breed from 5,500 to 9,000 feet. 
The following localities show the breeding range in the State: 
Littleton near Denver, 5,500 feet (Richards), near Trinidad, 6,000 feet 
(Cooke), up to 9,000 feet in Boulder co. (Gale); additional records 
are: Estes Park, summer (Kellogg), Fort Garland, October (Henshaw), 
Mesa co. in winter (Rockwell), Barr Lakes in winter (Hersey & Rock- 
well), San Juan co., breeding (Drew), and Fort Lewis, breeding (Gilman). 
Habits.—The Chickadee is a social creature, going 
about in small parties, especially in winter, among the 
cotton-woods along the stream-beds, and very actively 
searching the bark and winter buds for insects, their 
eggs and larvee, which form the bulk of its food all the 
year round ; they are undoubtedly of the greatest value 
