Seriously, though, this is the time of the year when birds start to migrate. They migrate because it gets too cold or too hard to find food. The answer depends on the bird.
Most field guides have maps showing where to see a particular kind of bird.
The map usually shows where the bird nests in the summer and where it lives in the winter. If the map doesn t show where the bird is in the winter, the chances are that it leaves North America and heads for South America where the seasons are reversed, and it is spring during our fall, and summer during our winter. Some maps don't show where the birds go along the way, but if they nest on the East Coast, chances are good that you can see them as they head south. More good questions. Some people think birds know when the hours of daylight begin to get noticeably shorter, but no one knows for sure.