May, 1918 117 THE DISTRIBUTION OF THE SUBSPECIES OF THE BROWN TOWHEE (PIPILO CRISSALIS) By H. S. SWARTH %VITH MAP AND FIGURES (Contribution from the Museum of Vertebrate Zoology of the University of California) HE RECENT acquisition by the Museran of Vertebrate Zoology of series of Brown Towbees /Pipilo crissalis) from sections not previously repre- sented in the collection, notably from many points in the Sierra Nevada, suggested the desirability of an examination of the entire group. The revision of the ranges of the three recognized subspecies, as here set forth, is based
mainly upon the collection of the California Museum of Vertebrate Zoology, to-
gether with the,Grinnell, Morcom and Swarth collections, deposited in that institution. In addition the writer is 'indebted for the use of specimens from Oregon, loaned by the University of Oregon Museum, through the courtesy of Dr. John F. Bovard, and for the privilege of examining the extensive series of thcse birds in the collection of J. and J. W. Mailliard, including many speci- u?ens from critical points not represented in the collection of the Museum of Vertebrate Zoology. Altogether, 353 specimens were used in this study. The Brown Towhee is one of several species of birds characterizing the Soho- ran zones in California, that'are so closely restricted in their range as hardly to extend-beyond the confines of the state. While the Brown Towbee /Pipilo cris- salis) of California is obviously similar to the Cafon Towbee (Pipilo uscus) of the southern Rocky Mountain region, the two being doubtless but recently de- rived from a common ancestry, the wide hiatus now existing between their ranges, together with the lack of intergradation between them, is sufficient justification ior their being regarded as distinct species. Indeed, the point is worth empha- sizing that while the range of Pipilo criss?is is comparable to the ranges of cer- tain other Pacific Coast species, such as Psaltr?parus rainlinus, Aphelocoma cali- fornica, and the west Californian' races ?f Pipilo maculatus, all with related ?orms in the Rocky Mountain region comparable to Pipilo fuscus, the Brown Towhee has no representative race in eastern California such as is possessed by each of the other bird species cited. It seems remarkable that no towhees of this group should exist on the east slope of the Sierras and in the Upper Sonoran zone of the desert mountains. The California Brown Towhee was first made known to science through the description by Vigors of Frgngilla crissalis (Zool. Voy. "Blossom", 1839, p. 19). His type specimen is listed in the collection of the British Museum as from Mon- terey (Sharpe, Cat. Birds Brit. Mus., xn, 1888, p. 754). Birds from the vicinity of Monterey belong to the reddish-colored race of the central coast region of Cali- ?ornia (though they do not show the extreme manifestation of the characters of that subspecies), and as there is no question of the migration of individuals to cause confusion, for the Brown Towhees are non-migratory, the name crissalis, applied to a specimen from this region, must, of course, be used for the central coast race. The species, long regarded as a subspecies of Pipilo fuscus, was not further divided until the description by Anthony (Auk, xn, 1895, p. 111) of Pipilo fuscus senicula, from San Fernando, Lower California. In 1899 McGregor (Bull. Coo-
