Sea Duck Secrets

Ranger Rick, March, 1999 by Claire Miller

Follow a scientist to the top of the world as he helps discover the secrets of a mysterious sea duck.

Eyeglasses are sometimes called spectacles, right? Well, this duck is called a "spectacled" eider because the pattern around its eyes looks like glasses.

What's happening to these beautiful ducks? We seem to be seeing fewer and fewer of them! That's what Paul Flint wondered about spectacled eiders (SPEK-tuh-kuld EYE-durz) a few years ago. He's a scientist who studies many kinds of ducks in western Alaska. Paul and other scientists figured that, before they could help the eiders, they'd have to learn all they could about them. But it wasn't going to be easy. "Their nests were hard to find, and we didn't even know where the ducks went in winter," Paul explains. But he and other scientists were prepared to meet the challenges.

Sniff, sniff. It's not easy to find a hidden nest!

SECRET NESTS "Spectacled eiders build their nests in soggy places that are knee-deep in mud," says Paul. "The females snuggle down in the grass, so their nests are almost impossible to see." How does he locate them? He takes along Ursus, a dog that's good at discovering nests (see photo below). By keeping track of the nests, scientists can discover how many of each female's eggs hatch. And they will know if a nest is destroyed by a predator such as an arctic fox. While Ursus searches, Paul gets ready to catch some ducks.

SECRET NETS "We stretch hard-to-see nets near the ponds where the ducks feed on water creatures," Paul explains. "When ducks fly in for a landing, they sometimes fly into a net instead!" Now Paul has caught a duck in the net, and he removes her carefully (right). He writes down the codes from the tag on her bill and her leg band. By keeping track of these codes, scientists have discovered that each female uses the same nesting spot year after year. Next, Paul quickly measures the length of the captured duck's bill (below, right) and writes that number down too.

Ursus has found a nest--but whose eggs are they?

SUPER SENSES Ursus continues to run all around the field looking, listening, and sniffing for signs of a nest. At last he's found one (far left). It belongs to a green-winged teal, which is another kind of duck.

FAKE EGG Now Ursus has found a spectacled eider's nest (left). Paul is planning to put the fake egg (shown below the nest) in with the other eggs. Why? The fake egg contains a thermometer and is attached to a radio. The radio will signal whether the fake egg is warm or cool. Then the scientists can tell whether the duck is on or off her nest. After the scientists leave, the female duck returns to her nest (below left). She's very hard for predators to see, because her feathers match the color of the grass. But the scientists will know she's there, because her fake egg will warm up a little.

NOW WHAT? Spectacled eiders don't have as many secrets as they once had. "We have learned that many of the ducks have been poisoned by the lead in old shotgun pellets," says Paul. "The ducks swallow the pellets accidentally while feeding in small ponds. There may be other problems too, so we'll continue to study the ducks. We want to discover all the problems, so people can do even more to help these very special Ospectacle-wearing' ducks!"

Where DO they go in winter?

Each little dot in the photo below is a spectacled eider. This is just one of the huge flocks of eiders that spend the winter in the middle of the Bering Sea (see map). Scientists were amazed to discover that all of the world's eiders--about 350,000 of them--come to this icy place. The ducks' warm bodies keep ice from forming as they swim around. And that allows them to dive for small clams and other food. There are few predators to worry about, and they don't have to fight over food with other animals. Until a few years ago, this place was the ducks' biggest secret. For years, scientists had put radios on some of the ducks. But the batteries in the radios had always lost power before winter. Then, in 1995, one of the radios sent a weak signal from the middle of the ice. At last the ducks' secret was out! The scientists not only had found the "lost" eiders. They also discovered that there are more spectacled eiders in the world than they once thought.

Nesting Area Wintering Area