This is Bird Note.

Powerful currents and rocky terrain make for a dangerous place to swim.

But for some birds, whitewater rapids have all the comforts of home.

This American dipper thrives in fast-flowing streams.

It's a plump steel-gray songbird about the size of a rabbit that's constantly bouncing on its heels as it hops along the bank, kind of like a swimmer ready to make a splash.

Propeled by its wings, the American Dipper walks

underwater as it picks out insect larvae from the stream bed. The harlequin duck is no stranger

to treacherous waves either. Named for their theatrical markings, Harlequin ducks spend the cold winter months

crashing through the surf along rocky coastlines, but they migrate inland near swift streams

for the breeding season to build their nests in cliff ledges and natural hollows.

One of the most elusive white water specialists is the aptly named Torrent Duck of the Andes Mountains.

The male has bold black and white facial patterns, and the female is mostly slate gray and

chestnut brown. These waterfowl are so exquisitely suited to their extreme lifestyle

that even their downy chicks look almost gleeful

as they plunge into the frigid, frothing flow of the raging rivers they call home.

For Bird Note, I'm Michael Stein.