NOCTURNAL BIRD MIGRATION

We’re all more or less familiar with the songs that birds sing by day. but tonight, if you live along the flight path of birds migrating south for the winter, you could listen for a different kind of bird call. I’m Jim Metzner and this is the Pulse of the Planet, presented by the American Museum of Natural History.

“What you want to listen for are short little call notes. Very high pitched. They sound sort of like a single cricket chirp. But these are little birds in migration.”

Bill Evans is a research associate at the Cornell Laboratory of Ornithology. Some years ago, late at night while on a camping trip, he heard migrating birds making these chirping sounds at night – something no one had apparently noticed or documented before. This accidental discovery launched Mr. Evans on a quest to learn more about the phenomenon.

“I have this passion for studying the night flight calls of migratory birds and birds give calls at night because when they are making a long migration, say a songbird is going to fly down from Canada or northern US and fly down to South America, say Peru or Brazil, if they fly at night, that allows them to rest and feed during the day. If they do make that long journey they may want to go with a couple buddies instead of just flying alone and how are they going to keep in touch? They can’t see each other, they’re flying at night. And the way they keep in touch is by giving little call notes. This is not full song like we hear during the day but this is just short little call notes. Or chip. And this is what most of the sparrows and warblers and thrushes and a lot of our little songbirds give in night migration.”

“For instance in New York State on a good night in fall migration. You know, maybe a light northerly wind, a lot of birds are leaving the breeding grounds and heading toward the tropics, if you got up on a hilltop and listened very carefully up in the sky you might hear ten thousand birds calls in a night.”

More on nocturnal bird migration in future programs. Pulse of the Planet is presented by the American Museum of Natural History. I’m Jim Metzner.

NOCTURNAL BIRD MIGRATION

The sounds that migrating birds make at night are quite different from those that they make by day.
Air Date:10/08/1997
Scientist:
Transcript:

We're all more or less familiar with the songs that birds sing by day. but tonight, if you live along the flight path of birds migrating south for the winter, you could listen for a different kind of bird call. I'm Jim Metzner and this is the Pulse of the Planet, presented by the American Museum of Natural History.

"What you want to listen for are short little call notes. Very high pitched. They sound sort of like a single cricket chirp. But these are little birds in migration."

Bill Evans is a research associate at the Cornell Laboratory of Ornithology. Some years ago, late at night while on a camping trip, he heard migrating birds making these chirping sounds at night - something no one had apparently noticed or documented before. This accidental discovery launched Mr. Evans on a quest to learn more about the phenomenon.

"I have this passion for studying the night flight calls of migratory birds and birds give calls at night because when they are making a long migration, say a songbird is going to fly down from Canada or northern US and fly down to South America, say Peru or Brazil, if they fly at night, that allows them to rest and feed during the day. If they do make that long journey they may want to go with a couple buddies instead of just flying alone and how are they going to keep in touch? They can't see each other, they're flying at night. And the way they keep in touch is by giving little call notes. This is not full song like we hear during the day but this is just short little call notes. Or chip. And this is what most of the sparrows and warblers and thrushes and a lot of our little songbirds give in night migration."

"For instance in New York State on a good night in fall migration. You know, maybe a light northerly wind, a lot of birds are leaving the breeding grounds and heading toward the tropics, if you got up on a hilltop and listened very carefully up in the sky you might hear ten thousand birds calls in a night."

More on nocturnal bird migration in future programs. Pulse of the Planet is presented by the American Museum of Natural History. I'm Jim Metzner.