THE BIRDS OF THE REPUBLIC OF PANAMA, 



PART 1: TINAMIDAE (TINAMOUS) TO 



RYNCHOPIDAE (SKIMMERS) 



By Alexander Wetmore 

 Research Associate, Smithsonian Institution 



INTRODUCTION 



The long, narrow Isthmus of Panama, which unites North America 

 on the one hand and South America on the other, is a geographic area 

 outstanding in its interest to biologists in the systematic field as the 

 land connection between these two regions of the Northern and 

 Southern Hemispheres. Present understanding of geologic history 

 indicates that the two areas were separated by open sea in the Tertiary 

 period for a vast space of time that began in the Paleocene epoch 

 and extended toward the end of the Pliocene. For 50 million years 

 South America remained isolated from other lands, while North 

 America had periodic union with Asia through land connections in the 

 present region of Bering Sea. The great diversity in plant and animal 

 life that now marks the Panamanian land bridge is a reflection of 

 invasions from the two adjacent continental areas. Study of present- 

 day distribution, variation, and relationship in any group is of deep 

 interest and valuable in details of scientific information. 



The present account is the first installment of a summary of what is 

 known of the birdlife of the area. My personal studies in the field 

 began in 1944 and have continued annually for approximately three 

 months each year since 1946, with laboratory investigation of speci- 

 mens and a survey of the published works of others who have made 

 contributions in this region. 



The number of kinds of birds known from the isthmus is so large, 

 and materials available are so extensive, that completion of the report 

 has required more time than originally contemplated. As there is in- 

 creasing demand for information on this subject, especially from those 

 engaged in investigation of diseases where species of birds may be 

 suspected as carriers, it has become desirable to present the summary 

 accounts family by family as they are completed in order that the 

 information may be available. This first installment covers the 

 families in systematic sequence from the tinamous, family Tinamidae, 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 150 (WHOLE VOLUME) 



