This is Bird Note. As darkness descends on a May evening, the voices of many birds go quiet.

But for some birds, especially those known as night jars, the music is just beginning.

In the moonlit shadows of an eastern hardwood forest, an eastern whipper will shouts out its name.

The same evening, in a southeastern woodland, we hear the loud calls of a chuckwills widow.

West of the Rockies, the voice of a common four-wheel echoes across a canyon.

Along the Rio Grande River, at the southern tip of Texas, a common perake calls from the thorns grub.

And in the desert night on the Arizona-Mexico border, a buff-colored night jar repeats its Spanish nickname Tuku Chio.

You can hear all the calls again, and again, at birdnote.org. I'm Mary McCann, and today's show is brought to you by the Bobbling Foundation.