No-^274. THREE NEW BIRDS— MEARNS. 923 
SITTA CAROLINENSIS NELSONI, new subspecies. 
ROCKY MOUNTAIN NUTHATCH. 
Type.—^o. 131242, U.S.N.M. collection. Adult male, taken October 
17, 1893, in the Huachuca Mountains, Arizona, by Edgar A. Mearns. 
Original number, 9725. 
Characters. — Largest known form of Sitta caroUrienMs. Bill large 
and rather stout, with contour of maxilla convex rather than straight 
above. Coloration dark. Under parts washed with gray and fulvous 
or fawn color, but less strongly so than in Sitta caroUnensis mexicana 
Nelson and Palmer.^ Measurements of type: Length, 151 mm.; alar 
expanse, 282; wing, 9-1; tail, 55; culmen (chord), 22; tarsus, 17.5; 
middle toe, with claw, 20. 
Geographic range. — Wooded mountains of northern Chihuahua and 
Sonora, Arizona, New Mexico, Colorado, and northward. 
Hemarl's. — In addition to its larger size, this form may be separated 
from the eastern bird b}^ its darker coloration, the back being more 
nearly slate color than plumbeous, and the color pattern of the tertials 
as in Sitta carol hiensis acideata, from which latter its larger size, 
stouter and differently shaped bill, and the gray and fawn color instead 
of pure white under parts distinguish it. In nelsoni the white of the 
tail-feathers is more extended than in other forms, and, excepting 
mexicana.^ the fawn color of the sides and abdomen of the young is 
more intense than in the remaining subspecies of Sitta carolinensis. 
It is resident, in the interior, on both sides of the Mexican border. If 
any migration occurs in winter, the migrants are the same as the resi- 
dent form, the bird of Colorado and the southern Rocky Mountain 
region being practicalh'^ identical. Comparative measurements are 
given below (pp. 924-926). 
^The Auk, XI, Jan., 1894, p. 45 (Mt. Orizaba, State of Puebla, Mexico). 
