16 
THE CONDOR 
Vol. XVII 
two males, this being most apparent in the heavier markings on the tarsus and 
toes of the former. There is some indication that the arid climatic conditions 
surrounding this form are conducive to rather more .marked fading of plumage 
in the course of months, than is the case with the California bird ; and this too 
despite the fact that the mode of life of the two subspecies is practically the 
same. In the juvenile example of huachucac the newly grown rectrices and 
remiges are noticeably darker than is the case with the adults, taken in April 
and July. In typical occidentalis, taking specimens similarly comparable, the 
difference is inappreciable. 
Careful comparison of the two series, from California and from Arizona, 
respectively, shows the following dissimilarities, aside from the generally 
paler coloration of the latter subspecies. 
Facial discs: In huachucac these are noticeably grayish. The ground color 
of the anterior two-thirds is practically pure white, of the posterior margin, 
light brown. There is little variation in the three specimens. In occidentalis 
this part is quite uniformly dark brown, with a limited grayish area anter- 
iorly. 
White spots on individual body feathers : Careful analysis of patterns of 
separate feathers from any part of the body shows throughout an extension of 
the white areas, with corresponding reduction in brown, in huachucac as com- 
pared with typical occidentalis. This is quite noticeable, for example, in the 
plumage of the upper breast, where a feather that, in occidentalis. is brown 
with two white spots, in huachucac frequently will have the two spots coa- 
lesced, producing a barred feather instead of a spotted one. 
Tail bars : In huachucac the tail bars are broader, and are more nearly pure 
white. The tendency in occidentalis is for them to become broken into spots. 
In both races the number of tail bars varies in different individuals and on 
different feathers, ranging from six to eight in number. 
White spots on outer webs of primaries: In huachucac these are broader, 
more nearly white, and generally more conspicuous. 
Throat and median line of abdomen: The throat patch in huachucac is 
pure white, and covers a relatively large area. In occidentalis the unmarked 
portion is rather more restricted,' and is frequently huffy or grayish in color. 
The center of the abdomen is more nearly pure white in huachucac, as com- 
pared with the duskier hue usually seen in occidentalis. 
Tarsus and toes: In the two adult males of huachucac tarsus and toes are 
almost pure white, sparsely flecked with pale brown. The single adult female 
at hand has these parts much more heavily marked, being in this respect quite 
like certain examples of occidentalis, though in most specimens of the latter 
form the legs are somewhat darker. It is noteworthy that in the juvenile male 
of huachucac tarsus and toes are pure white, unmarked, while the juvenile 
female of occidentalis at hand has these parts heavily marked. The inference 
that might be drawn from these facts is that the observed variation in color 
and markings of toes and tarsus is to some extent due to difference in sex. 
This, however, is not corroborated by conditions in the series of adult occident- 
alis. In the two juvenals described in my previous paper on the species (Univ. 
Calif. Puhl. Zool., vol. 7, 1910, p. 7), toes and tarsus were pale colored and un- 
marked, but unfortunately the sex of these birds had not been ascertained. 
Under tail coverts: These are parti-colored feathers of white and brown. 
In huachucac the white areas are the most extensive, while in occidentalis the 
