452 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



The range of the California bushtit, as now understood, includes the 

 interior valley regions, chiefly in the Lower and Upper Sonoran Zones, 

 exclusive of desert regions, from Jackson County, Oreg., to Kern County, 

 Calif. Mountain ranges and intervening deserts both seem to serve as 

 effective barriers at certain places between the two subspecies. 



I cannot find anything in the literature and have received no con- 

 tributed notes to indicate that any of the habits of this inland race differ 

 materially from those of the coast form. As it lives in a somewhat 

 less humid environment, it probably selects some different species of 

 trees and shrubs for its nesting sites, such as madrones, junipers, and 

 sage on occasions, though it evidently shows a preference for oaks. It 

 apparently builds its nests of similar materials and eats similar kinds of 

 food. In short, practically all that has been written about the coast 

 bushtit would apply equally well to the present form. Their eggs are 

 indistinguishable. The measurements of 40 eggs of californicus average 

 14.1 by 10.5 millimeters; the eggs showing the four extremes measure 

 15.3 by 10.0, 13.0 by 11.1, 12.8 by 10.1. and 14.0 by 9.9 millimeters. 



Enemies. — Dr. Herbert Friedmann (1929) reports the finding of an 

 egg of the dwarf cowbird in a nest of the California bushtit, but, as it 

 was found in Riverside County, it probably refers to the coast bushtit. 

 This seems to be the only known time that the species has been imposed 

 upon. It is a mystery how the cowbird can enter such nests as those of 

 the bushtit and the verdin without so enlarging the entrance as to cause 

 the owners to desert. 



In this connection, the reader is referred to what E. C. Stuart Baker 

 has to say about similar difficulties encountered by the Himalayan 

 cuckoo, in his contribution to my Bulletin 176, page 87. 



FSALTBIPARtrs MINIMITS MELANURUS GrlnneU and Swarth 

 BLACK-TAILED BUSHTIT 



In describing and naming this Baja California subspecies, Grinnell 

 and Swarth (1926) say that it is "as compared with Psaltripartis mini- 

 mus minimus, of southern California, of darker, more plumbeous gen- 

 eral coloration. In minimus there is a brownish tinge to the plumage. 

 above and below, that is lacking in melanurus. This difference is most 

 outstandingly apparent on wings and tail ; melanurus is, comparatively 

 speaking, a 'black-tailed' bushtit. * * ♦ The color differences distin- 

 guishing melanurus and minimus are readily apparent in fresh plumaged 

 birds. Bush-tits change rapidly in appearance with wear and fading of 

 the feathers, and wom-olumaged individuals of these two subspecies no 

 longer exhibit the differences that are so easily seen in early fall. 



