And by analyzing radar images, Benjamin van Doren showed that the Tribute in Light, across seven nights of operation, waylaid around 1.1 million birds. The beams reach so high that even at altitudes of several miles, passing birds are drawn into them. Warblers and other small species congregate within the light at densities up to 150 times their normal levels. They circle slowly, as if trapped within an incorporeal cage.
