Groundhog Day represents something far more significant than a rodent predicting the weather: it's the half-way point between the vernal equinox and the winter solstice. No matter what that hapless critter does-goes back in or stays out-it still means winter is half over.

Every couple of days, I snowshoe out into my yard to feed the birds. Yes, snowshoe. That’s how deep the snow has been here in northern Grafton County. The suet has disappeared quickly, and I've replenished the supplies a couple of times.

I’ve even made my own suet "pies" to help fill the birds’ need for insulating quantities of fat by mixing the suet with black sunflower seeds. One reward for putting out hulled sunflower seeds has been the appearance of a brilliant red cardinal.

After several years’ absence, the bluejays have come back to my feeders in groups of five or six. They love the cracked corn and oyster-shell grit I put out for them. I started putting out the oyster shells after I discovered that the rat-a-tat-tat I heard coming from the front of our house wasn't a woodpecker looking for insects, but a bluejay trying to find calcium in paint.

Like all female birds, the lady jays need calcium to strengthen their eggshells, and, as it turns out, calcium is an ingredient in most house paints. I also put out eggshells from hard-boiled eggs and from raw eggs, boiling the discarded shells first in hot water to make sure they won't pass along any diseases.

In my travels around the house and garden, I've noticed tracks on top of and tunnels into and beneath the snow. These tunnels into the “subnivean” (under-the-snow) zone intrigued me. The insulating snow traps heat from the earth below, so the temperature at the interface of soil and snow remains stable, hovering just around 32 degrees, no matter how cold it is above. Often I see a little head pop up from beneath, grab some seeds and vanish back under the snow.

Mice, red squirrels, weasels, voles, moles and shrews remain active in the subnivean zone. The weasel is the predator from within, living among the creatures he will prey on. Owls and hawks watch from branches above hoping to make a meal. Patterns made by the tunnels emanate on top of the snow; try looking down to see them from a window or higher ground. Predators such as coyotes, foxes, and the owls and hawks can often sense motion under the snow and make their strikes before actually seeing the animal below.

Sometimes, I even see where tiny tracks lead across the snow surface and then just stop. Evidence of an animal airlifted by an owl or hawk and quickly eaten. No trail of blood and feathers left to tell a gruesome story, just air and snow.

Another creature that benefits from the insulating qualities of snow: the Ruffed Grouse, Bonasa umbellus. Grouse often burrow into deep snow to spend the night. When fresh snowfall hides the entry hole, an unsuspecting snowshoer may get the surprise of her trip as the grouse suddenly bursts from the unmarked snow beneath her feet.

Not only mammals, but also insects and arthropods live below our line of vision under the snow. The Snow Fly, Chionea valga, and the Elongated Crab Spider, Tibellus oblongus, not only live in subnivean airspaces, but also mate and raise their young there, often providing nutrition for other creatures under the snow. Their sources for food are often the Springtails, Hypogastrura nivicola, which New Englanders refer to as snowfleas.

Harmless to humans, these tiny members of the order Collembola exist all over the world, but here in New Hampshire they remain subnivean most of the winter and come up into the daylight, scientists speculate, to mate. They usually appear on top of the snow only when the air starts to warm a bit in late February, and then resemble black pepper sprinkled over the snow.

Winter animals don't grumble about the snow and ice, they persevere or die. The myriad ways they’ve adapted to life beneath and above the snow testify to the web of life as simultaneously wonderful, awful and surreal.

Recent research in the Antarctic has revealed prolific life existing even beneath icebergs. When icebergs “calve” from glaciers, they carry with them minerals and nutrients from the soil encased within the glacier from whence it came. This enriches the waters below the ice, providing sustenance for microscopic and larger life forms, which in turn provide food for animals in a wide radius.

Some research evolving from this source of life may help solve problems caused by global warming. There are theories that the deep oceans of our polar areas may actually serve as carbon repositories.

Whether spring returns in six weeks or less, all that life below and out of our sight may prove to be more important than we realized.

By Helen Downing, Master Gardener