Floating in the summer on an air mattress on the crystal-clear water of the Salmon River, far in the north of California
, far from nothing, I looked up and saw a mud-and-vegetation bird nest - really a hole which led to a jug-shaped vessel - stuck high on a rock wall. I thought, swallow
But that wasn't quite right. First, it was a bit large for a swallow's nest, perhaps a foot in diameter, and included rather more mossy stuff than mud; then again, when have you ever seen one swallow's nest? Swallows always run around and nest in groups.
It was the nest of an ouzel, or American dipper (Cinclus mexicanus). John Muir's favorite bird.
Later I saw the bird itself. Several of them, actually. They are not of impressive appearance, being smallish (perhaps a little smaller than an American robin), unremarkable grey birds who blend in well with the sun and shade of mountain rivers. If you watch one for a bit though you will see him bob rapidly up and down, up and down, in the motion that gives him his popular name. They feed underwater, on aquatic insects, larvae of caddisflies, mayflies, beetles, bugs and mosquitoes; they will eat fish eggs too, and very tiny fish. Worms and snails; like most birds, whatever they can get. Meat eaters, though. They almost fly through the water, and are able to swim against even a swift current.
The bird has a long, sweet warbling song which echoes among the rocks bordering the mountain streams and rivers they love, blending with the sound of falling water. It is so lovely a song that you want to hold your breath to listen.
The American dipper ranges from Alaska down almost to the Mexican border, but only on the west side of the Rocky Mountains. It does not occur in dry southern California. It is found only along swift rocky streams and rivers (like the Salmon), and seems to favor cold water. The nest can be on sheer rock over the river (like the one I saw) or sometimes on concrete bridges over mountain streams.
The bird demands very clean water and its presence is an indicator that all is well on that measure.
John Muir's rather poetic description is well worth reading.
See also Kaufman, Kenn, Lives of North American Birds, Houghton Mifflin Company, Boston, New York, 1996