Dear Bird Folks,
Late one night I was on the roof of my house and I kept hearing birds call overhead. Why were birds up and calling so late at night?”
– Tom, Chatham
I think a more important question should be, what were you doing out on your roof so late at night? Was your wife listening to the opera again? The birds that you were hearing were migrating birds. Many songbirds like to migrate at night. At night they don’t have to worry about becoming a meal for falcons. Also, flying at night allows the birds to rest and feed during the day. Flying at night does have its drawbacks though. Birds can get lost if the weather changes and they can collide with things like radio towers or power lines.
The calls that you hear are calls that birds use only in migration. The birds give off little cheep notes that don’t sound at all like the song that we hear them use on land. That’s why it’s hard to identify them by sound. They seem to like moonlit nights with little or no wind. The moonlight helps them see and they can save energy if there aren’t any strong winds to deal with.
A fun thing to do on the next calm, moonlit night is to set up a spotting scope and focus on the moon. On a good night you can see hundreds of birds zipping past as they head south. But some nights you might be bored and not see any birds at all. However, birds or no birds, it would still be better than listening to the opera.