OBSERVATIONS ON THE BIRDS OF ARGENTINA, PARAGUAY, 

 URUGUAY, AND CHILE 



By Alexander Wetmore 

 Assistant Secretary, Smithsonian Institution^ 



INTRODUCTION 



The successful operation of the Federal Migratory Bird Treaty 

 in according protection, hitherto uncertain, to migratory game and 

 insectivorous birds, with resultant increase in many species, led 

 naturally to inquiries regarding the present status of birds that 

 migrate in winter beyond our borders. Particularly was this the 

 case with those species, mainly shore birds, that pass south into the 

 southern portion of the South American Continent. To gather first 

 hand information on the questions involved the Biological Survey, 

 United States Department of Agriculture, in May, 1920, dispatched 

 the writer to Argentina with instructions to carry on the desired 

 observations. During the extended period of field work incident to 

 such a task there was abundant opportunity to make representative 

 collections of native birds and to record many points of interest 

 concerning their distribution and habits. 



Since observation of shore birds was the main object in mind, 

 travel was restricted largely to the level sections where suitable 

 shores and marshes were available, so that collections were made in 

 the main in the lowlands. The area covered extended from north- 

 ern Paraguay south to northern Patagonia, and from the eastern 

 border of Uruguay west to the foothills of the Andes in Mendoza, 

 and included a limited section near Valparaiso, Chile. Points for 

 work were chosen carefully to allow comprehensive survey of as 

 large an area as practicable. Studies of the specimens secured to- 

 gether with field observations, where pertinent, are presented here- 

 with in as much detail as is warranted. 



For assistance while in South America, thanks are due especially 

 to Dr. Roberto Dabbene of the Museo Nacional in Buenos Aires, 



^ The investigations covered in the following pages were made when the author was 

 on the staff of the Bureau of Biological Survey, U. S. Department of Agriculture. The 

 report has been brought to completion since he became Assistant Secretary of the 

 Smithsonian Institution. 



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