^62 BULLETIN 197, UNITED STATES NATIONAL MUSEUM 



tral Mexico (Jacala) ; central Durango (Rio Nazas) ; central Sonora 

 (Ures) ; and northern Lower California (San Fernando). West to 

 western Lower California (San Fernando and San Telmo) ; and south- 

 western and central California (San Diego, Santa Barbara, Sargent, 

 Sacramento, Marysville, and Red Bluff). 



Winter range. — The winter range of the races of the Bell's vireo is 

 discontinuous, but present information is inadequate to assign the 

 range of each race. The species occurs in winter in the Cape region 

 of Lower California as far north as Santa Margarita Island ; in the 

 tropical region of southern Sonora as far north as Ures and probably 

 in northern Sinaloa. It is found from southern Guerrero (Coguca 

 and Chilpancingo) through Oaxaca (Chivela and Tehuantepec) to 

 Guatemala (Ocos, Sacapulas, and Gualam) ; and in El Salvador 

 (Barra de Santiago and Divisadero). The species has been reported 

 to reach northern Nicaragua, but no records of specimens are at pres- 

 ent available. 



The range as outlined includes the entire species, which has been 

 divided into four subspecies or geographic races. Bell's vireo, the 

 typical race (F. h. helli), breeds from Colorado to Illinois south 

 through eastern Texas to Tamaulipas; the Texas vireo (F. h. medius) 

 breeds from southwestern Texas to central Mexico; the Arizona 

 vireo (F. b. arizonae) breeds from southeastern California to south- 

 western New Mexico south to Sonora and Chihauhua ; the least vireo 

 (F. h. pusillus) breeds in central and southwestern California south 

 to about latitude 30° in Lower California. 



Migrations. — Early dates of spring arrival are : Texas — Austin, 

 March 26. Oklahoma — Tulsa, April 15. Missouri — Concordia, 

 April 13. Illinois — Quincy, April 18. Iowa — Ames, April 30. 

 Kansas — Manhattan, April 22. Nebraska — Stapleton, April 24. 

 South Dakota — Dell Rapids, April 24. Arizona — Tucson, March 21. 

 California — Santa Barbara, March 7. 



Late dates of fall departure are: California — Azusa, October 3. 

 Arizona — Tombstone, October 20. Colorado — Fort Morgan, Octo- 

 ber 6. New Mexico — Chloride, September 20. South Dakota — Sep- 

 tember 5. Nebraska — Red Cloud, October 1. Kansas — Onaga, 

 September 27. Iowa — Grinnell, September 12. Missouri — Columbia, 

 October 3. Oklahoma — Oklahoma City, October 18. Texas — Cove, 

 October 15. 



Casual records. — A specimen was collected in Durham, N. H., on 

 November 19, 1897 ; a specimen has been recorded as taken at Detroit, 

 Mich., on May 26, 1885, but the original label has been lost and the 

 correctness of the locality has been questioned; a specimen in fall 

 migration was collected on Deer Island, Miss., September 18, 1939. 



Egg dates. — Arizona : 35 records, April 24 to July 1 ; 18 records, 

 April 29 to May 29, indicating the height of the season. 



