But it is in withstanding the force of heavy rapids that his strength of wing in this respect is most strikingly manifested.

The following may be regarded as a fair illustration of his power of sub-aquatic flight.

One stormy morning in winter when the Merced River was blue and green with unmelted snow, I observed one of my ouzels perched on a snag out in the midst of a swift-rushing rapid, singing cheerily, as if everything was just to his mind; and while I stood on the bank admiring him, he suddenly plunged into the sludgy current, leaving his song abruptly broken off.

After feeding a minute or two at the bottom, and when one would suppose that he must inevitably be swept far down-stream, he emerged just where he went down, alighted on the same snag, showered the water-beads from his feathers, and continued his unfinished song, seemingly in tranquil ease as if it had suffered no interruption.
[Illustration: OUZEL ENTERING A WHITE CURRENT.] The Ouzel alone of all birds dares to enter a white torrent.

And though strictly terrestrial in structure, no other is so inseparably related to water, not even the duck, or the bold ocean albatross, or the stormy-petrel.