Excerpt from The Birds of the Republic of Panama, Vol. 1: Tinamidae (Tinamous) To Rynchopidae (Skimmers) 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. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.