American Ornithologists' Unionis collaborating with JSTOR to digitize, preserve and extend access toThe Auk.The Niche-Relationships of the California Thrasher Author(s): Joseph Grinnell Source: The Auk,Vol. 34, No. 4 (Oct., 1917), pp. 427-433Published by: American Ornithologists' UnionStable URL: Accessed: 27-09-2015 15:40 UTCYour use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at info/about/policies/terms.jspJSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]This content downloaded from 184.108.40.206 on Sun, 27 Sep 2015 15:40:23 UTCAll use subject to JSTOR Terms and Conditions
1917 ] GRINNELL, The California Thrasher. 427 into the body of the partly eaten bantam and replaced it in the same spot where he found it. Next morning the seemingly im- possible was made a practical certainty, for he found the body of a screech owl with the claws of one foot firmly imbedded in the body of the bantam. He very kindly presented me with the owl which, upon dissection, proved to be a female, its stomach containing a very considerable amount of bantam flesh and feathers, together with a great deal of wheat. (It seems probable that the wheat was accidentally swallowed with the crop of the bantam during the feast, but there was so much that it seems strange the owl did not discard it while eating). How a bird only 9.12 inches in length could have dealt out such havoc in so short a time is almost in- credible, but, 'although purely circumstantial, the evidence against the owl appeared altogether too strong for even a reasonable doubt. The doctor and I wished to make as certain as possible, however, so the poisoned bantam was replaced and left for several days, but without any further results. For the above mentioned reasons I am rather doubtful as to the net value of this owl from an economic standpoint, although birds in a wild state would not give them such opportunities for such wanton killing as birds enclosed in pens. THE NICHE-RELATIONSHIPS OF THE CALIFORNIA THRASHER.' BY JOSEPH GRINNELL. THE California Thrasher (Tozostoma redivivum) is one of the several distinct bird types which characterize the so-called "Cali- fornian Fauna." Its range is notably restricted, even more so than that of the Wren-Tit. Only at the south does the California Thrasher occur beyond the limits of the state of California, and in that direction only as far as the San Pedro Martir Mountains and 1 Contribution from the Museum of Vertebrate Zoology of the University of California.