A Radar and Direct Visual Study of Passerine Spring Migration in Southern Louisiana

RADAR studies of bird migration have been restricted to latitudes north of 32? N. These studies have contributed greatly to our knowledge of migration, but have examined only a portion of the long-distance migrations made by many bird species. No radar studies of migration have been published for regions nearer the equator where environmental conditions are more constant. This paper reports on a radar and telescopic study of spring migration on the Louisiana coast of the Gulf of Mexico between 29? and 310 N, one of the first landfalls that migrants reach after leaving the tropics and crossing the Gulf (Figure 1).