ROUTES OF MIGRATION 61 General Considerations 61 Flyways and Corridors 62 Narrow Routes 65 Converging Routes 65 Principal Routes From North America 69 Atlantic Oceanic Route 69 Atlantic Coast Route and Tributaries 70 Mackenzie Valley-Great Lakes-Mississippi Valley Route and Tributaries 73 Great Plains-Rocky Mountain Routes 75 Pacific Coast Route 76 Pacific Oceanic Route 80 Arctic Routes 80 PATTERNS OF MIGRATION 82 Loops 82 Dog-legs 87 Pelagic Wandering 90 Leap-frogging 90 Vertical Migration 91 Pre-migratory Movements 91 Vagrant Migration 92 ORIGIN AND EVOLUTION OF MIGRATION 95 WHERE WE STAND 100 BIBLIOGRAPHY 102 LIST OF BIRD SPECIES MENTIONED IN TEXT 115 =PREFACE= Frederick C. Lincoln's classic work on the "Migration of Birds" first appeared in 1935. It was revised in 1950 and has been out of print for several years, after selling over 140,000 copies. Unfilled requests by many individuals, clubs, and institutions prompted the Office of Conservation Education (now the Office of Public Affairs) in the U.S. Fish and Wildlife Service to petition another update for reissue. This publication incorporates the results gathered by research biologists in the U.S. Fish and Wildlife Service to meet these requests. Lincoln's original intent was to present to the American public a summary of the facts on bird migration as they existed in the early 1930's. He wrote with a style that made the topic fascinating to the young and old, to the educated and uninformed, and to the ardent observer as well as the backyard watcher. An attempt has been made to retain this style, while incorporating material from often highly technical research efforts. Much of the content and organization of the original publication has been maintained, but new sections were added to incorporate recent concepts and techniques. Other concepts, known to be inconsistent with present knowledge, have been deleted. Because graphics are of utmost importance in this type of publication, most of the original figures were preserved and, where appropriate, new illustrations have been added.