Laura Erickson's For the Birds

(Recording of a Trumpeter Swan)

My four-year-old and two-year-old just checked out a videotape of Disney’s version of “The Ugly Duckling” from the library, and I suddenly find myself answering all kinds of unexpected ornithological questions, like: Do swans really lay their eggs in Mallard nests? Well, it’s not likely–but many waterfowl do lay an egg or two in other birds’ nests if their own nest isn’t finished in time–this is called “dumping”–so I guess it’s possible. A swan egg is a lot bigger than a duck egg, so if there was a swan egg in the middle of a clutch of duck eggs, it would hold the mother up a lot higher, away from her own eggs. That means the ducklings would not be very warm, so they would hatch later than normal. It takes Mallard eggs 23-29 days to hatch, and swans 35-40, but with the termperature differential, they might hatch out together.

“Are mommy ducks really that mean–to chase off a little baby swan?” No–a real mallard that sat on a swan egg would probably take care of the baby swan–called a cygnet–just as lovingly as she’d take care of her own ducklings. And the baby swan would think the Mallard was its real mother. All waterfowl key in on the first moving thing they see after they hatch. Not only do they follow it as their mother, but it becomes a permanent imprint of what they will later choose for a mate. So the cygnet will probably never mate with another swan. It might star in a television sitcom, “I Married a Duck.”

Disney’s Ugly Duckling found its way into a robin’s nest, and the mother robin fed it a worm before she discovered that it was not her own baby. Could that really happen? Nope. Baby ducks and swans don’t have the foggiest notion of how to beg for food–their mothers don’t feed them at all–they simply lead them to food. Anyway, even though a mother robin might be tricked into accepting another species of songbird as her own baby, a cygnet looks way too different to fool her.

What kind of swan is the Ugly Duckling? Well, the mother looks like a Mute Swan–the beautiful swan with the “S” shaped neck and the orange markings on the bill seen in story books. Because of its beauty, this is the swan most often kept in captivity, in zoos and parks. The Mute Swan is native to Europe, but was introduced to North America– there’s a wils colony of them living in Ashland, Wisconsin. But Disney’s swans make vocalizations similar to the Trumpeter Swan.

(Recording of a Trumpeter Swan)

The Trumpeter Swan used to nest in Minnesota, until market hunting brought it to the verge of extinction. Now it is being reintroduced to the Midwest after careful management saved it in the western states. Bringing the true story of the Ugly Duckling full circle, one of the ways the DNR is reintroducing the Trumpeter is to sneak its eggs into the nests of Mute Swans. Maybe they’ll drop one by mistake into a Mallard nest.

(Recording of a Mallard)

Maybe I should pack away our VCR and read “The Trumpet of the Swan” to the kids instead. This is Laura Erickson, and this program has been “For the Birds.”