Air Date: Week of December 31, 1999

Living On Earth commentator Sy Montgomery walks on the frozen ponds near her home in New Hampshire, following in Thoreau's footsteps to search for life through the "icy window."

Transcript

MONTGOMERY: It seems we oughtn't be able to do this: to walk on water.

CURWOOD: Commentator Sy Montgomery spends a lot of time each winter on the frozen ponds near her home in New Hampshire.

MONTGOMERY: But as I walk out onto the surface of the ponds I canoe and swim in each summer, I, too, experience a miracle. The ice serves as a window into lives both above and below it, now vastly different than in warmer seasons.
Some pond creatures spend the winter hovering, coma-like, between life and death. A carp can survive embedded in a block of ice. A natural antifreeze keeps its cells from freezing and bursting. On the soft mud of pond bottoms, frogs, toads, and salamanders overwinter in a sort of suspended animation, living without drawing a breath or eating a meal. The mud is always a few degrees warmer than water, so these animals don't freeze. Like the carp, they subsist on oxygen dissolved in the water, absorbed directly through the skin.

But not all is still beneath the ice. Sometimes, when a slow freeze creates ice that's clear and free of bubbles, I can see down through the ice as clear as looking through a glass-bottomed boat. I've seen fish swimming under my feet. A friend once looked down and saw a muskrat swimming beneath him, holding his front feet under his chin and trailing a stream of pea-sized bubbles. If you're lucky, you might get to see a mink swimming down there, too. He's probably looking for the muskrat.

Even when the ice is thick and clouded, you can still use it as a window into other lives. Look at the surface. Especially after a light snow, tracks show up brilliantly on the ice of a pond. You might see the webbed prints of beavers. They leave their warm stick-and-mud lodges to harvest more trees and then drag them back under the ice to their underwater passageway into the lodge. You might see the neat tracks of foxes by February, often in pairs as they find mates, who can now take the shortcut across the pond instead of around it.

You'll notice the absence of hoof tracks here. A slick surface is no good if you have feet permanently encased in high heels. Predators know this and sometimes try to drive deer across frozen ponds. If this has happened, you can read the whole story in the snow over the ice.

The ice at Walden Pond inspired one of Thoreau's most moving realizations. "Heaven," he wrote, "is under our feet as well as over our heads." Or, as Paul Simon put it, "One man's ceiling is another man's floor."

(Music up and under)

CURWOOD: Commentator Sy Montgomery writes to us from her home in Hancock, New Hampshire, and comes to us from New Hampshire Public Radio.