Nov., 1905 | 
ATRATUS VERSUS MEGALONYX 
173 
colored, and with white markings on tail, wing coverts and scapulars, more extensive; rump 
grayish; wing and tail longer than in megalonyx . 
Types — £ adult; no 3972, coll. H. S. S.; Miller Canyon, Huaehuea Mountains, Arizona; 
May 20, 1903; collected by H. S. Swarth. 
Description — Head and neck all around, black; lower breast and abdomen, white; sides, 
chestnut, paler than in megalonyx , with a few partly concealed black markings on the edge, be- 
tween the chestnut of the sides and the white belly; under tail coverts, pale fulvous. Wings, 
black; greater and middle coverts broadly tipped with white, forming two bars across wing; outer 
web of scapulars, white, except for an almost imperceptible edging of black; interscapulars with 
white spot on outer web; size of spots decreasing toward middle of back, but very few feathers on 
the back not showing some white markings. Rump, grayish, in marked contrast to the back. 
Three outer tail feathers tipped with white; lateral ones with outer web white for about terminal 
third. Length 224. «Alar expanse 290. aWing 91. Tail 109. White spot on lateral tail feathers 35. 
5 adult; no. 3875, coll. H. S. 3 .; Miller Canyon, Huaehuea Mountains, Arizona; May 5, 
1903; collected by H, S. Swarth. 
Description — Generally similar to the male, but black of head, neck, back, etc., paler, 
more slaty. Chestnut of sides, paler. As compared with female megalonyx the chestnut sides 
are appreciably paler; white areas on wings, scapulars, etc., much more extensive; and the inter- 
scapulars are nearly all with white markings on the outer web. Length 215. «Alar expanse 270. 
« Wing 86. Tail 101. White spot on lateral tail feather 27. 
Young — The only two juveniles of 7 non t anus in my possession are not sexed, but compared 
with juveniles of megalonyx of both sexes, from Fort Tejon and Pasadena, all in the streaked 
plumage, they are appreciably paler, with wing bars broader, and white spot on tip of lateral tail 
feather, much longer. 
Measurements — 
Wing 
Tail 
White spot 011 
outer tail feather 
50 £ £ Los Angeles Co., Cal. 
86.2 
97-1 
24. 
7 £ £ Mt. Pinos, Cal. 
85.4 
97-7 
25.6 
3 £ £ Monterey, Cal. 
83.6 
96.6 
23.3 
10 £ £ Palo Alto, Cal. (P. m. falcifer) 
83.8 
93 -i 
21.4 
17 £ & S. Arizona and New Mexico (P. m . montanus ) 
92.2 
106.5 
31.2 
25 $ 5 Los Angeles Co., Cal. 
81.3 
91.6 
22.1 
4 5 $ Mt. Pinos, Cal. 
81.2 
91.2 
20.5 
2 $ j Monterey, Cal. 
80.5 
96.5 
19 . 
9 $ $ Arizona and New Mexico (P. m. montanus) 
84.6 
97.2 
28.6 
Range — The higher mountains of eastern Arizona, eastern California ? central and southern 
Nevada and Utah, western Colorado and New Mexico, south into northern Mexico. The western- 
most extension of the species in Arizone might be indicated by a line drawn from the Santa Rita 
to the Hualapai Mountains. Specimens of montanus were examined from the following locali- 
ties: Huaehuea Mountains and Fort Verde, Arizona; Rincon and Fort Union, New Mexico; Fort 
Loveland, Colorado; Provo, Utah; and West Minaca, Chihuahua, Mexico. 
Besides the easily appreciable difference in color and proportion between 
megalonyx and montanus , there is a remarkable difference in the habits of the two 
races. Megalonyx is resident throughout its range in California, where it is found 
from the sea level well up into the mountains; “up to the limit of the undergrowth” 
(Grinnell, Pub. No. 1. Pasadena Acad. Sci., 40); “observed only below 6,500 feet” 
on Mt. Pinos (Grinnell, Auk, XXII, 1905, 389). It is probably more abundant in 
the willow thickets of the lowlands and along the streams in the lower foothills 
than anywhere else, and is strictly resident, the only migratory movement what- 
ever being a partial descent from the higher parts of its range in midwinter. 
Montanus is found in the mountains only , of Arizona, New Mexico, etc., where 
it is resident; and I have never seen it below 5,000 and but seldom below 5,500 
feet. In the ranges I visited I found it equally distributed from 5,500 to 10,000 
feet, and even when the snow was deep on the ground the birds did not descend 
into the foothills. I can find no record of the occurrence of this bird anywhere in 
Arizona or New Mexico except in the mountains, nor does it seem to have ever 
a Measurements from freshly killed specimen in millimeters. 
