2 



NORTH AMERICAN FAUNA 65 



1940 through 1960. Other specimens were borrowed from the principal 

 museums and from several universities and individuals. When the 

 breeding specimens were sorted out and their distribution studied, 

 there appeared to be several undescribed races. A statistical analysis 

 of the measurements of specimens was made to determine whether 

 this method would substantiate the presence of new subspecies. 



It is very significant that more than 450 Z. a. asidtica banded in 

 Texas have been reported from localities in Latin America south 

 of their breeding places and on wintering grounds as far away as 

 Costa Rica. More than 250 banded Z. a. mearnsi from Arizona have 

 been reported from western Mexico. The patterns of these recoveries 

 are an invaluable aid to understanding racial distribution of this 

 species. 



The extent of migration of the races that breed in Central America 

 is not yet adequately known. Some subspecies appear to be mostly 

 sedentary, such as alticola in the Altos of Guatemala (Saunders, 1951) . 

 Skutch (1964, p. 224) reported that they nested in March and April 

 in the Sierra de Tecpan, Guatemala, up to 9,000 feet above sea level, 

 but after the rainy season began in mid-May they disappeared until 

 late in the following November. This indicates that in part of their 

 range there is a seasonal movement, perhaps mostly altitudinal. But 

 we lack specimens of this race to show its distribution south of 

 Guatemala. 



Members of the Bureau of Sport Fisheries and Wildlife to whom 

 I am especially indebted include John W. Aldrich for advice on taxo- 

 nomic questions, Ralph Andrews for field assistance on our Mexican 

 survey in 1960, Richard C. Banks for advice on taxonomy. Earl Bay- 

 singer for tabulations of banding and recoveries, Thomas D. Burleigh, 

 formerly with the Bureau and now retired, for skins for study, Allen 

 Duvall for suggestions in studies of banding, Aelred D. Geis and 

 Robert G. Heath for statistical assistance, Mary W. Mann, artist, 

 Bird and Mammal Laboratories, for the distribution map and figures, 

 and Lester L. Short, Jr., formerly with the Bureau and now with the 

 American Museum of Natural History, for help with taxonomic 

 questions. 



On the surveys in Guatemala in 1947, Charles O. Handley, Jr., 

 U. S. National Museum, aided in obtaining specimens, as did Clarence 

 Cottam, Director, Welder Wildlife Foundation, on the 1957 survey 

 in Mexico. 



I also wish to thank the following institutions and individuals for 

 lending specimens essential for this study and for assistance when I 

 visited and studied some of the collections: Academy of Natural 

 Sciences of Philadelphia (R. M. deSchauensee and James Bond) ; 

 American Museum of Natural History (Dean Amadon) ; British 

 Museum (J. D. MacDonald) ; Carnegie Museum (Arthur C. Twomey 

 and Kenneth C. Parkes) ; Field Museum of Natural History (E. R. 

 Blake and the late Boardman Conover) ; Colorado Museum of Natural 

 History (Alfred M. Bailey and Robert Niedrach) ; Louisiana State 



