Some species, such as purple martins, orchard orioles and ruby throated hummingbirds, began departing in late July to winter quarters in Central and South America and the Caribbean. Some waterfowl, though, may still be southbound as late as December.
More birds also migrate in the fall, when birds born in spring join older birds for the trek south.
You can see some of this great natural pageant this fall during free, open-to-the public bird walks led by Atlanta Audubon Society experts. More information: atlantaaudubon.org.
IN THE SKY: From David Dundee, Tellus Science Museum astronomer: The moon will be last quarter on Wednesday. Mercury is low in the east at dawn; Venus and Mars rise in the east about an hour before dawn. Jupiter is low in the west at dusk and sets about two hours later. Saturn is low in the southwest just after dark and sets around midnight.