19H J Grinxell, Range of the Mockingbird in California. 295 



being indistinguishable from examples from the San Diegan dis- 

 trict and from the deserts. 



The distribution of the Mockingbird east of the Sierran divide 

 is evidently modified more by season than is the case anywhere 

 on the Pacific slope of California. It would appear from a con- 

 sideration of all the records of the species so far available that it 

 occurs in summer chiefly if not altogether on the slopes of the moun- 

 tains, dropping into the adjacent valleys in winter, and at that 

 season even extending, in small numbers, by a veritable migratory 

 movement, south over the Mojave Desert. 



The northernmost record east of the Sierras is from the heads of 

 Owens River and Owens Valley, about latitude 37° 40' (Fisher, 

 N. Am. Fauna, No. 7, May, 1893, p. 127). Thence south through 

 Owens Valley and along the ranges to the eastward there are a 

 number of summer records. Though observed in Death Valley 

 in January and April, not a single one was found there in June 

 (Fisher, 1. c). 



No positive information is at hand indicating that the species 

 breeds in the lowest and hottest parts of the southwestern deserts, 

 where, however, it occurs in winter. Exploration along the valley 

 of the lower Colorado River by the expedition of the Museum of 

 Vertebrate Zoology in 1910 showed the Mockingbird to be common 

 there from February to April; but there were no indications that 

 the individuals were about to nest in the region. On the contrary 

 everything pointed towards their being winter visitants from a 

 breeding area elsewhere. 



The only record-station in the coast region north of San Fran- 

 cisco Bay is San Geronimo, Marin County. Mailliard (Auk, 

 XV, April, 189S, p. 197) records a male specimen taken there 

 December 30, 1894. In the coast region south of San Francisco 

 Bay, beginning at the north, we have the following records. Red- 

 wood City: specimen taken September 5, 1891; "rarely seen here; 

 I have met with but three others during the past twenty-five years" 

 (Littlejohn, Zoe, III, Jan., 1893, p. 362). Stanford University: 

 male specimen secured February 17, 1893 (Van Denburgh, Proc. 

 Am. Philos. Soc, XXXVIII, Nov., 1899, p. 177); individual seen 

 December 20, 1904, and "for a week or two subsequently " (Fisher, 

 Condor, VII, March, 1905, p. 55). Hay wards, Alameda County: 



