BENNETT'S WHITE-TAILED HAWK 221 



Thayer's view of protective coloration, has been worked out to the undoing of 

 its prey, the small mammals that look up at it against the light of the sky 

 into which its whiteness enables it to fade ; while on the other hand the small 

 mammals have become colored like the prairie to protect them from furred 

 and feathered hunters that look earthward. 



DISTRIBUTION 



Range. — Southern Texas south through Central America and 

 through South America from the Colombian Andes, east to Trinidad 

 and Surinam, and south through Brazil, Uruguay, and Argentina to 

 the Rio Negro. Accidental in Arizona. 



The range of the white-tailed hawk extends north to southern Texas 

 (Marfa, Boquillas, Bee County, and Calhoun County) . East to Texas 

 (Calhoun County, Rockport, and Brownsville) ; Vera Cruz (Jalapa) ; 

 probably Yucatan (Merida) ; Trinidad (Port of Spain) ; Dutcli 

 Guiana (Surinam) ; eastern Brazil (Matto Grosso, Baliia, Minas 

 Geraes, Sao Paulo, and Parana) ; Uruguay; and Argentina (Buenos 

 Aires, Cape San Antonio, and the Rio Negro ) . South to Argentina 

 (Rio Negro). West to Argentina (Rio Negro, Mendoza, Tucuman, 

 and Formosa) ; eastern Bolivia; Colombia (Rio Negro and Bonda) ; 

 Panama; Costa Rica (San Jose, Cerro de Santa Maria, and Laguna 

 de Ochomogo) ; Guatemala (San Geronimo and Duenas) ; western 

 Mexico (Oaxaca, Puebla, Colima, and Zacatecas) ; and southwestern 

 Texas (Marfa). 



The white-tailed liawk has been separated into three geographical 

 races, all of which are included in the outline presented above. Sen- 

 nett's white-tailed hawk {Buteo a. hypospodius) is found from the 

 Lower Rio Grande Valley in the United States south through Mexico 

 and other Central American countries to the Andes of Colombia 

 and Venezuela; B. a. colonus occurs from Colombia to Surinam in 

 Dutch Guiana, including also the islands off the north coast of South 

 America, as Aruba, Bonaire, Curagao, and Trinidad; B. a. alhicau- 

 datus is found in southern Brazil, Uruguay, and in Argentina south 

 to the Rio Negro. 



Casual records. — In the spring of 1897, betAveen Florence and Red- 

 rock, Ariz., G. F. Breninger collected an Qgg that he reported to be of 

 this species. The adult was flushed from the nest but was not ob- 

 tained. Two years later (January 15, 1899) he collected a male at 

 Phoenix, Ariz. If no mistake was made in the identification of these 

 specimens they remain unique as being the only records for the United 

 States outside of Texas. 



Egg dates. — Texas and Mexico : 69 records, February 1 to July 4 : 

 34 records, March 30 to April 24. 



