Nighttime Flights Of Songbirds

  Some cloudless night in September, when the air is clear, you may see birds flying across the yellow face of the moon! September is peak migration time for millions of songbirds heading south from North America to more tropical latitudes. Nocturnal migrants of the same species, such as orioles, warblers, sparrows, and tanagers, call as they fly, enabling flock-mates to stick together. Many of these flight calls are distinctive, enabling those with an excellent ear to identify them as they pass.