Even during the quiet of winter, the region's back yards and parks swarm with signals from resident or transient animals. Each sign has a story to tell for those who know how to read what they see: blue jay feathers on the ground, a two-toed hoofprint in the snow or white specks in a pressed-down circle of grass.

The blue jay feathers probably are remnants of a fight with a cat. The position of the hoofprints can reveal whether the animal was male or female, large or small, running or walking. And the white specks likely are eggshells from a duckling born last spring.

Take a walk in the woods in Reston with Douglas B. Inkley, and clues start jumping out. Despite his elevated title -- senior science adviser at the National Wildlife Federation -- Inkley also is a close-to-the-ground naturalist.

One cold December day, he heads out the door of the federation's headquarters, which backs up to Fairfax County parkland. Within a few minutes, he spots a vertical slice of scraped-off bark about two feet up the trunk of a small bush. It is a "buck rub."

Male deer grow antlers each year. During the fall mating season, they rub the antlers against a hard surface to scour off the soft velvet that cover them.

"He probably did it in the early morning or at dusk, right here, not 20 feet off the road," Inkley says.

Along the edge of the woods, he spots two deer prints. One is probably that of a fawn; it is the width of his two thumbs. Judging by size, he thinks the other came from a doe. (Skilled trackers also can distinguish adult male prints from female prints based on the relative position of the front and rear hooves. If the rear track is to the inside of the front track, it is a male, because males have wider shoulders; if on the outside, it is a wider-hipped female. The pointed end of the heart-shaped track is the direction in which the animal is headed.)

Other signs that white-tailed deer have been here include a circle of flattened grass that is about the size of a sleeping animal, and small bushes with densely growing, bitten-off branches. There even is a small pile of white and brown hair, with bits of brown attached -- deer hide, perhaps left by an animal that had been hit by a car.

The woods are scattered with fallen logs, a good place to look for animal traces because wild creatures often use them as highways. Several in these woods are littered with cracked acorns -- squirrel food. On top of one is something that resembles a dog dropping; Inkley guesses it is from a fox. He sometimes finds logs covered with raccoon scat, which is crammed with seeds and berry skins.

There also are several shallow mounds, covered with leaves. They are likely animal dens -- "you don't just find a mountain of soil in the woods," Inkley says. Sure enough, when he pushes aside the leaves atop one, there is a hole. He suspects a fox or woodchuck lived there.

(A cautionary note: Do not handle scat without gloves, and do not reach into an animal's den because something might be in there.)

Inkley's worldview includes the idea that your success in tracking does not depend merely on having fresh snow or mud that reveals recent footprints. His advice is to get to know the animal you are looking for. Study what it eats, where it likes to live, how it moves around. In this, he is a hunter, but without a rifle. "I'm paying attention to the whole landscape," Inkley says.

-- D'Vera Cohn

Deer leave lots of evidence of their presence, including areas of flattened grass, where they may have lain, and nibbled bushes.