Blane Klemek column for June 27: Dippers are unique birds
I don't have a "Life List," so to speak, of birds I wish to observe before I'm long gone. My favorite field guidebook, "Golden Book's Birds of North America," is scribbled with entries of first-time observations, complete with dates and locations, next to the birds' illustrations. But even this form of personal record is incomplete. I haven't documented every single first encounter of every bird I've ever observed.
There is one bird, however, that I'd like to add to my so-called life list. It's the American dipper. Here's a bird that I've only seen in various wildlife television programs, films, and in books, articles, and scientific journals. And evidently, at least according to the National Audubon Society's "The Sibley Guide to Birds," the American dipper has occurred in Minnesota. Just how many records of confirmed occurrences are unknown.
Of the Minnesota records that I've been able to uncover through a quick Internet search, the most likely locations - indeed, authenticate observations - are along the North Shore within the fast flowing, cold water streams and rivers flowing into Lake Kitchigami (Superior). Of all places in Minnesota - what with the area's mountain-like landscape and clear running rocky streams - the American dipper would find itself much at home, albeit hundreds of miles east of its normal and preferred range and associated breeding and nesting habitats.
The American dipper is classified as a songbird, or passerine (perching bird). A stocky little fellow about 7.5 inches long, the short-tailed bird is rather ordinary looking in many respects, save for the bird's very unordinary, un-passerine-like behavior. After all, its common name, "dipper," is for a very good reason.
Of all songbirds, there's no other quite like the extraordinary American dipper. In fact, this species of dipper is the only dipper in all of North America. Other species, which include four other dippers, inhabit South America, Europe and Asia. The range of the American dipper includes Alaska and southward through the western continental United States, and south to the mountains of Panama.
American dippers are squat birds with rather long legs for their size. To compare with other common birds, the dipper looks like a gray catbird without much of a tail. Likewise, and because of its short tail, American dippers also resemble wrens.
Not very colorful, (overall dark gray with slightly brownish heads) both sexes' are identical in appearance. They also have white eyelids that can be observed when the birds blink, appearing almost "flashy" when they do so. But what they perhaps lack in visual beauty is more than made up for by the birds' charisma. No other songbird behaves quite like the American dipper does.
As its charming namesake seems to suggest, American dippers not only submerge themselves underwater when hunting for food, they also constantly "dip," or bob, their bodies up and down as they perch on rocks along their fast-flowing riverine habitats. American dippers are also the only songbirds that regularly swim on the surface of the water - their unusually oily feathers are no doubt some of the reason for this amazing ability.
The diving dipper is so suited to its environment, so specialized, that the bird finds itself residing virtually competition-free. Few other birds exploit underwater resources like the American dipper. The astonishing bird is visible one moment bobbing up and down atop river rock, while the next moment it has disappeared into the water; only to resurface on or nearby the same rock a moment later.
Searching for aquatic invertebrates like larvae that hide and crawl on stream bottoms, as well as other aquatic organisms such as tadpoles and small fish, including fish eggs, American dippers are experts at finding and capturing these prey items in the fast moving waters of mountain streams. They even have the ability to "fly" underwater, using their wings to aid in propulsion, maneuvering, and stabilization in swift flowages.
One of the interesting aspects of dipper behavior has to do with the belief that the bird communicates with one another, in part, through their bobbing and blinking actions. As anyone can attest, streams and rivers are often noisy environments complete with cascading waterfalls and turbulent water coursing over and around rocks and woody debris.
Though dippers are vocal birds that sing high-pitched whistles and trills, in addition to emitting high and buzzy call-notes, their aural ability in such environments is frequently compromised. Thus, visual displays are important to dippers that are intent on communicating and keeping track of one another.
Regarding physical attributes for their watery world, American dippers also possess two interesting features that better equips them for underwater foraging. In order to see well, dippers have nictitating, transparent membranes that cover their eyes while underwater. Moreover, dippers have movable nasal flaps of skin that close shut so water cannot enter their nasal passages.
As such, one of these days I hope to observe the delightful American dipper, for myself, in its natural habitat. I have no doubt that I could spend countless mesmerized moments watching the dipper bobbing its body and diving and swimming for its food. And perhaps I will someday; maybe hunting this fall in the Colorado Rockies, or maybe even along a fast moving trout stream on the North Shore, as I get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife. He can be reached at firstname.lastname@example.org