Vail Daily column: Dippers dance into the water
Behind binoculars, I often bemoan my ignorance as I struggle to identify birds. Sometimes, though, lack of knowledge leaves room for the delight of discovery. Take, for example, my first sighting of an American dipper, but stop reading right here if you want to discover the dipper for yourself. Just go sit by a tumbling area of a mountain creek. You will probably see a little gray bird that looks like a fat wren poking around at the edge of the water. Be patient and he will do something you don’t expect.
My first dipper was scratching around the rocks in Bighorn Creek in East Vail where the water tumbles out under I-70. I knew he wasn’t a junco, another little gray bird who pokes around on dryer ground, because he was fatter, with short, stubby wings, a short cocky tail and no rusty wash on his back. And his eyelids flashed white every time he blinked. He also bobbed up and down rhythmically on longer legs than a junco’s. His little dance looked like the motion of a child bouncing at the end of a diving board, getting up the courage for a headfirst plunge. Just as that analogy crossed my mind, the little bird jumped, feet first into the deeper water rushing by his rock. He disappeared from sight and I thought I had witnessed a bird suicide.
About 15 seconds later the little gray guy popped out of the water, upstream of his entry point, a seemingly impossible feat for a human who had jumped into such a strong current, let alone a 6-inch bird that looked nothing like any proper waterfowl. By the time I gave up watching him about an hour later, he had performed many jumps, had been visible walking around on the bottom stirring up the sediment with his beak, and also swimming against the current like a mini-penguin. Even I could figure out that he was foraging for food.
My excited Minnesotan description of the bird’s behavior to a Colorado native was met with, “Oh yeah, a dipper. That’s what they do.” I thought he meant that they dip into the water, but the name actually refers to the bird’s bobbing onshore dance.
American dippers reside along running streams and especially mountain streams along North America’s west coast, inland to the continental divide, north as far as the Arctic Circle, and south into Central America. Dippers travel up and downstream with freeze and thaw cycles, and are the only songbirds to subsist on bugs, larvae and tiny crustaceans dredged up from flowing streams. They are also the only ones to get eaten occasionally by trout or to be caught by fishermen. The American dipper, drab gray all over with minor brownish head tones, differs from the flashier European version which has a strongly contrasting white neck and breast.
Dippers are specially adapted for life in their unique niche. High hemoglobin levels enable them to carry enough oxygen to stay underwater for up to 30 seconds at a time. A third eyelid called a nictitating membrane protects the eye under water. The birds preen frequently, waterproofing their feathers with oil from an oversized uropygial gland under the tail. Their oil-coated outer feathers act like Gore-Tex, covering a dense down layer next to the skin. Air flight with such a heavy jacket and short wings requires every feather, so molting happens all at once, rendering the dipper flightless for 4 -14 days after the breeding season, until the new feathers are all in place. In this respect the dipper is like other waterfowl.
Dippers also shed their families. After singing long, complicated and loud songs to find each other over the noise of rushing water, a dipper pair builds or reuses a dome shaped nest under a stream side cliff or bridges. They raise their young, send them out to find their own streams, and then strip the cozy linings from nest interiors to discourage the children from coming back to the same territory. No cosseting the kids in the dipper world.
Betsy Holter is a medical writer (byline Elizabeth A. Reid, MD) and a volunteer at Walking Mountains Science Center.