BLANE KLEMEK: The American Dipper is no dip of a songbird
The American dipper is classified as a songbird. A stocky little species at about 7.5 inches long, this short-tailed bird is rather ordinary looking in many respects, save for the bird's very unordinary, un-songbird-like behavior. After all, its common name, "dipper," is for a very good reason.
Of the Minnesota records that I've been able to uncover through quick Internet searches, verified, documented observations have been recorded along the North Shore within the fast flowing, cold water streams and rivers flowing into Lake 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.
In October, I received an email from retired biologist Mary Jane Gall from Woodbury, Minn., who reported observing a single dipper in her yard while she was doing some lawn work. She told me that the bird allowed her to get quite close, too, as the bird seemed to be foraging in a pile of day lilies that she had just recently cut down. Lucky her!
Indeed, 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.
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 songbird that regularly swims 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.
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 covers their eyes while underwater. Moreover, dippers have movable nasal flaps of skin that close shut so water cannot enter their nasal passages. Also interesting, and rare among songbirds, is that dippers molt both their wing and tail feathers all at once, becoming flightless for a period of time just like ducks and geese do.
I hope to observe the delightful American dipper for myself in its natural habitat someday. I know I could spend countless mesmerized moments watching the dipper bobbing its body and diving and swimming for its food. And while the species does show up from time to time along fast moving streams of the North Shore, our best opportunities to observe this fascinating water songbird will occur much further west as we get out and enjoy the great outdoors.
Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at firstname.lastname@example.org.