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Volume XV September-October, 1913 Number 3 
A REVISION OF THE CALIFORNIA FORMS OF PJPILO MACUIATUS 
SWAINSON, WITH DESCRIPTION OF A NEW SUBSPECIES 
By H. S. SWARTH 
with one map 
(Contribution from the Museum of Vertebrate Zoology of the University of California) 
T he SPOTTED TOWHEE {Pipilo viaculatus) is a common and character- 
istic bird over a large part of California. Its range is included almost alto- 
gether in the Upper Sonoran and Transition zones. Its absence from nearlv 
all parts of Lower Sonoran is probably chiefly due to the lack of suitable associa 
tional conditions over most of the arid regions comprising this zone ; for in some 
places, as in the Lower Sonoran San Joaquin Valley, this towhee is found, though 
in small numbers, in the limited portion of the region which is adapted to its needs. 
Six geographic races of this species are here recognized as occurring within 
the state. Five of them permanently occupy definite and fairly well-defined areas 
within the state ; the sixth occurs only as the merest straggler. On the accompany- 
ing map (fig. 47) is shown the distribution in California of the five resident suh- 
species, platted from specimens and data in the Museum of V ertebrate Zoology. 
A comparison of this with Grinnell’s (1902) map of the faunal areas of the state 
shows a close paralleling of the outlines of the ranges of the various subspecies 
with those of certain of the faunal areas. This, of course, is what is to be expected 
in a non-migratory and somewhat variable species, and occurs in this towhee as in 
Melospiza, Thryomanes, and certain other birds. Where there are striking differ- 
ences in the two maps they can in most cases be explained satisfactorily by the 
towhee’s known manner of zonal distribution. 
In California the species is restricted substantially to the Upper Sonoran and 
Transition zones, debarred from the extremes of Lower Sonoran and Boreal, but 
otherwise not affected by zonal changes. Thus the Colorado Desert (taking the 
term as it is used on Grinnell’s map), lying wholly within the Lower Sonoran 
Zone, has no representative of the species, except P. m. curtains as a winter visit- 
ant in a restricted portion of the region. 
