WINTER CAME to the west wood over the weekend. It went away again in a day or two, the way winter does around here, but it reminded the creatures that live there, and one who often visits, that the fair fat days are numbered and the hard lean times are coming.

Good times are hard enough for the west wood's deer and turkeys and rabbits and squirrels -- and those that prey upon them -- because the wood is part of a Virginia Piedmont farm where they must compete with cattle. Cows graze the grass closer than a lawn, browse the evergreens and twigs from ground level to higher than a fawn can reach, and vacuum up the acorns.

But this year there are no acorns. Last year and the year before they showered down so heavily that passing through a grove of oaks was as dicy as walking on marbles; there were so many that the cattle couldn't eat them all. The deer and turkeys prospered, and the squirrels lazed through both winters, basking on branches and seldom having to dig up a stored nut, so many of them still lay on the ground through spring. Even late-season fawns, thin sad things that seldom survive, waxed fat and endured the starving time, late January through early March.

Many of the weaklings reproduced. Never in recent years have there been so many creatures in the west wood, and so little for them to eat. By Thanksgiving there was nothing left. The crash hasn't come yet because the farmer has been in no hurry to finish cutting his corn, several acres of which stand rustling in the upper corner of the east field, the hard heavy ears hanging down.

Even the groundhogs have stayed up late to get in on it. At daylight the deer and field mice who came in the night to feed, and the raccoons and owls that came to feed on the field mice, give way to the dayshift's turkeys and squirrels, and the hawks and foxes that come to feed on the squirrels.

There are both the reddish fox squirrels and gray squirrels in the west wood, and while there will be far fewer of both by spring, the lash of nature's law is falling harder on the grays. Both species make the perilous journey from the wood to the field several times a day, but more of the fox squirrels make it home again.

A fox squirrel will heft as much as several pounds, well over twice the size of a gray, making Big Red just a little too formidable for the resident redtailed hawks. And only a truly hungry fox will try to run his namesake down, because the fox squirrel's teeth and claws can rip like a buzzsaw. The red's way of going shopping for corn is to dash across the open field, grab an ear and rush home all rumble-tumble, sometimes kicking and rolling the corn along.

The gray squirrel sidles along the fence- row, cowering low at the least movement and fleeing for the trees if so much as a crow flies over. This seems to amuse some of the crows, which will alter course to cruise the fenceline as they fly over the field, so that on a single trip a squirrel may cover many times the distance from woods to corn.

And then comes the hard part. Even a stunted ear's quite a burden for a gray squirrel, and if he tries to run, the corn in his jaws will foul his front paws, so that his flight has a spastic quality that would be funnier if the animal's plight weren't so pitiful.

In the late forenoon a red fox that was lying in wait for a gray squirrel looked up sharply at a muffled cough from the visitor, who had been sitting so still so long that the woods had forgotten him. The fox stared long at the unmoving shape beneath the tree, then went back to squirrel watching.

The fox was crouched where the fence meets the wood, flattened down and down in the leaves until his reds and whites and blacks and golds were all of a blend with them. He had seen the squirrel head out to the cornfield and was waiting for its return. Coming crosswind, the ear of corn blocking half his view, the squirrel had no warning and no chance. There was a pounce, a brief flurry, a little shriek. The fox trotted off to its den at the edge of the south field, holding its head just that high that the squirrel's tail did not brush the ground.

Then winter came. Wind began to shudder the tops of the trees, and snow fine as fog and cold as death came smoking through the woods, burning the cheek and stinging the eye and driving from the west wood the only creature that had the choice to stay or go.