Radar imagery from the Buffalo, New York NEXRAD location during spring migration, May 23, 2001. The radar device is located at the center of the screen, surrounded by bright colors showing migratory bird activity. The relative number of birds in each pixel on the radar screen is indicated by the color coded scale on the left side of the screen. In this case, deep reds and purples indicate larger numbers of birds. Notice that Lake Ontario and Lake Erie are outlined by bird activity. Since the image is showing migratory landbirds that are taking flight at the onset of nocturnal migration, we would not expect to see any migrant activity over the lakes. However, as the night goes on, we can see that the birds fly over the lake. Note that the line of colors running north-south through Lake Erie to the west of the radar location is a line of rain storms, and not bird activity.