February 17, 2009

Little Dipper

For those of you who have sat in meetings with me, watching as I nervously break one pen lid (and necklace) after another, I bring you a bird that seems to share my issue with holding still. It's actually a bird with talents that would wow even you non-birding folks, but for some reason it was named for its odd habit of bobbing up and down.

Well, a coworker was lucky enough to see one of these avian nervous Nellies recently, and I decided it was time to give it its due on this blog. Ladies and gentleman, I present to you Your BOTW, the American dipper.

Fact: The American dipper is a chunky, dark gray songbird with short wings and tail and a large head. It has white eyelids that are quite obvious when it blinks.

Fact: The American dipper is named for its habit of dipping—basically bending its legs and bouncing its body up and down. Now whether this is a nervous tic like my pen tapping or necklace twisting, scientists really aren’t sure. But dippers do tend to dip more when disturbed, approached by humans, or even aroused.

Fact: Don’t be fooled by its anxious habits or monastic garb. The American dipper has extreme skills for a little songbird. It makes its life in rushing mountain streams, literally riding the rapids and walking along icy streambeds to find food.

Fact: Dippers can dive and swim under water by flapping their wings. They can even walk along the bottoms of streams using their long toes to grasp rocks.

Fact: I probably don’t have to tell you that mountain streams are cold (refreshingly cold, if you believe Coors commercials). But the American dipper is well-equipped to handle icy waters even in the winter with its thick coat of feathers (including a layer of down, much like that on ducks) and its ability to decrease blood flow to vital organs.

Fact: The American dipper has nasal flaps to help prevent water from entering its nostrils, large glands that produce its very own waterproofing oil, and strong eye muscles that help it see underwater. This is a great video to show you what the dipper does underwater. (It's professionally produced by National Geographic.) Twenty or 30 seconds should give you a good idea.

Fact: Just what is the American dipper seeking at the bottom of those icy streams? Mostly insects and insect larvae, and occasionally tiny fish and fish eggs.

Fact: Streams plays a major role even in the dipper’s sexual and nesting habits. They copulate on rocks in the middle of streams. And, according to The Birds of North America Online, one dipper couple was even observed having aerial sex a few meters above the stream, tumbling into the water, and continuing to copulate as they floated downstream. Is that an extreme bird or what?!

Fact: American dippers build nests of moss and grass right alongside streams, but they need places that aren’t threatened by flooding, are inaccessible to predation, and have some sort of horizontal support. The undersides of bridges are a popular spot.

Fact: Both parents usually feed the nestlings after they hatch. Within 16 days, nestlings can dive, swim, and pull themselves out of the water.

Fact: Perhaps in an attempt to utilize limited resources, parents will sometimes split up, each taking half of the nestlings to establish their own territory. No weekend visitations, here. Once territories are established, the once happy family will rarely cross any unmarked borders.

Fact: I’ve gone on too long about the American dipper (because it's so cool). But, if you’ve read all the way to the end, congratulations!

This has been Your BOTW!

1 comment:

Jill said...

What an amazing little bird. Me and the kids loved the video showing the American dipper swimming.

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