Wylie Barrow Gregory J. Smith 2005 <p>Because of its geographic position, Louisiana plays an important role in the hemispheric-scale phenomenon known as the Nearctic-Neotropical bird migration system. Each year millions of landbirds migrate across or near to the coast of the Gulf of Mexico. Birds migrate in large, broad fronts that sometimes exceed 2 million individuals, and there is an advantage for them to take a direct north-south route (the shortest distance).</p><ul><li>During migration seasons, nearly all of the migratory landbird species of the eastern United States, as well as many western species, use the coastal plains of the western gulf.</li><li>Spring migrants arrive with depleted energy reserves and depend on Louisiana's coastal habitats to provide food and cover after long gulf crossings.</li><li>Fall migrants depend on Louisiana’s coastal habitats for food to store fat reserves just prior to gulf crossings in autumn.</li><li>Mortality during the migratory period can be high. Recent research on the black-throated blue warbler (<i>Dendroica caerulescens</i>) indicates that more than 85% of the annual mortality for the species occurs during migration.<br></li></ul><p>Migrants en route tend to concentrate in habitats adjacent to ecological barriers; DOI land managers need to identify key coastal landscape features that are important to these birds.</p><p>Because of the vastness of the North American continent, it is nearly impossible to delineate movement patterns and migration pathways by using traditional ground-based surveys.</p> application/pdf 10.3133/fs20053069 en U.S. Geological Survey Migratory bird pathways and the Gulf of Mexico: Importance of Louisiana's coast reports