Real-time analysis maps show intensities of actual bird migration as detected by the US weather surveillance radar network. Migration traffic rate is defined as the number of birds that fly across a 1 km transect line per hour, with transect line running over the earth’s surface perpendicular to the direction of movement of the birds. All graphics are relative to the Eastern time zone. When present, the red line moving east to west represents the timing of local sunset, the yellow line represents the timing of local sunrise. Areas with lighter colors experienced more intense bird migration. Orange arrows show directions to which birds flew. Green dots represent radar locations for which data are available; red dots represent radar locations with no data available. Note that many radars in mountainous areas (e.g. the Rockies) have obstructions that restrict radar coverage, providing the appearance of no migration where migration may be occurring.
Support for this research comes from from Leon Levy Foundation, NASA, Edward W. Rose Postdoctoral Fellowship, and Amazon Web Services. The BirdCast project, a collaboration among Cornell, Colorado State University, University of Massachusetts Amherst, and Oregon State Univeristy, was funded by grants from the National Science Foundation and Leon Levy Foundation.
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