410 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



rufous in the crissal. In the California and LeConte's thrashers, the 

 iris is always brown; in the crissal it is usually represented as light 

 yellow, though Ridgway (1907) described it as brown; in other species 

 of the genus the iris is yellow or orange. 



Enemies. — Hearing a succession of frenzied shrieks in the yard one 

 day, I hastened out to find a thrasher in the grip of a sharp-shinned 

 hawk. Upon seeing me the hawk immediately flew away, leaving its 

 intended victim apparently little the worse for the encounter. In 

 this instance the thrasher's vocal chords had proved its best de- 

 fensive weapon. 



From the nature of its habits the thrasher would seem to be especially 

 vulnerable to terrestrial enemies, but it is undoubtedly a bird of more 

 than average sagacity, and I have seen no indication that many of the 

 adults fall victim to cats or other prowlers. Because of the scant 

 height at which the nest is usually placed, there must be a considerable 

 loss from semiterrestrial nest-robbers, such as skunks, banded racers, 

 and perhaps alligator lizards, as well as from the California jay. 



Dr. Grinnell (1917) surmises that in view of the thrasher's dull 

 brown coloration, swiftness of foot, and poor flight, the chaparral cover 

 may be quite as valuable in its protective effect as it is in furnishing a 

 suitable foraging groimd. 



DISTRIBUTION 



Range. — California and northwestern Baja California; nonmigra- 

 tory. 



The California thrasher is found north in California to extreme 

 southern Humboldt County (Thorn) ; central Trinity County (Hay- 

 fork) ; Shasta County (Baird) ; and Tehama County (Manton). 

 East to Tehama County (Manton) ; the western slope of the Sierra 

 Nevada (Grass Valley, Placerville, Murphy, El Portal, and Walker 

 Pass) ; western San Bernardino County (Hesperia and Redlands) ; 

 Riverside County (Palm Springs) ; eastern San Diego County 

 (Jacumba) ; and northwestern Baja California (Hanson Laguna, 

 Sierra San Pedro Martir, and San Fernando) . South to northwest- 

 ern Baja California (San Fernando and Rosario). West to the 

 Pacific Ocean in Baja California (Rosario, San Quintin, and En- 

 senada) ; and California (San Diego, Los Angeles, Santa Barbara, 

 Monterey, Nicasio, Ukiah, Cummings, and Thorn). 



The range as given for the entire species is divided into two sub- 

 species. The Sonoma thrasher {T. r. sonomae) occurs in the northern 

 part of the range south to Eldorado, San Joaquin, and Santa Cruz 

 Counties; the California thrasher {T. r. redivwicm) occupies the 

 range from there southward. 



Egg dates. — California: 132 records, December 15 to June 27; 72 

 records, March 20 to May 8, indicating the height of the season. 



