Why are tall buildings a trap for migrant birds?
Lighted structures are dangerous to migrants. Some buildings intrude into their flying space, such as skyscrapers or communication towers. For reasons that are not well understood, birds are attracted to lights on these structures, circling them until exhausted and unfit for the remainder of their migratory journey. These birds may crash into buildings or windows, or become easy prey for crows, hawks and gulls at sunrise.
