This is Bird Note.

There are two species of American dowagers,

the long-billed and the short-billed.

These plump brownish shorebirds are maddeningly similar,

but if you listen to them, you'll be able to tell them apart.

Here's the high-pitched call of the long-billed Dowager.

And now, the low, mellow call of the short-billed.

These calls might seem unimpressive,

but take a listen to the short-billed Dowager's breeding songs.

The birds fly 150 feet above ground and then glide slowly earthward. Their beaks wide open as they're

making these calls. You can hear they're bubbling and trilling from up to a quarter mile away.

At the end of the glide, the birds suddenly fall through the air and then sometimes rise again for another round of musical airborne acrobatics.

For Bird Note, I'm Mary McCann.