364 BULLETIN 19 6, UNITED STATES NATIONAL MUSEUM 



Some early dates of fall arrival in the winter home are: Cuba — 

 Habana, August 13. Guatemala— Remote, Peten, July 30, Panaja- 

 chel, September 7. 



Egg dates. — Lower California: 12 records, May 8 to July 23; 7 

 records, June 25 to July 19. 



California: 108 records, April 5 to July 12; 58 records, May 16 to 

 June 12, indicating the height of the season. 



South Carolina: 11 records, April 19 to May 22; 7 records, May 7 

 to May 22. 



Texas: 11 records, April 15 to May 25; 6 records, April 23 and April 

 24. 



POLIOPTILA CAEKULEA AMOENISSIMA Grinnell 



WESTERN GNATCATCHER 



HABITS 



Under the name western gnatcatcher (Polioptila caerulea obscura) 

 Mr. Ridgway (1904) described the blue-gray gnatcatchers of the 

 Southwestern United States, from the interior of northern California 

 to northern Mexico and Lower California, as far south as Cape San 

 Lucas, as "similar to P. c. caerulea, but gray of upper parts slightly 

 duller and black at base of inner web of outermost rectrix more 

 extended, usually showing beyond tip of under tail-coverts." His 

 type came from San Jose del Cabo, and he evidently thought it 

 might be only a winter visitor, for he said of its occurrence there "in 

 winter only?". He therefore applied the name obscura to all the 

 western gnatcatchers. 



Subsequently, Dr. Joseph Grinnell (1926) discovered that "the 

 materials now accessible in sufficient amount show that there is a 

 separately recognizable race of Blue-gray Gnatcatcher resident in the 

 restricted faunal area known as the Cape San Lucas district of Lower 

 California." He therefore restricted the name obscura to the Lower 

 California race and proposed the name amoenissima for the birds of 

 the west outside of the southern tip of Lower California. He charac- 

 terized amoenissima as "similar to P. c. obscura Ridgway, of the Cape 

 San Lucas region, but wing and tail (especially the tail) longer, bill 

 slightly slenderer, and median lower surface less clearly white, more 

 imbued with very pale gray." 



The 1931 Check-list gives the breeding range of this form as "from 

 northern interior California (Shasta County), southern Nevada, 

 southern Utah, and Colorado (El Paso County) south to northern 

 Lower California, Chihuahua, Sonora, and Colima." 



In California the favorite haunts of the western gnatcatcher are 

 the warm, dry foothills covered with chaparral, small oaks, and other 

 small trees and underbrush, as well as the groves of cottonwoods in 



