BRAINERD, MINN. — Last week's cool, cloudy and windy weather discouraged fishing activities around the state. However, the rough weather that kept anglers off the lake sent some deer hunters into the woods, or at least got them thinking about it.

I spent part of one of those blustery days last week scouting for acorns. Already the red acorns are easily visible, and the bur oak acorns -- although smaller than the red oaks -- are noticeable, too. At least in central Minnesota it appears a bumper crop of red oak acorns will greet hunters this fall. Bur oak acorns are less abundant but still above average in quantity.

I used binoculars to scan the tree tops to determine which oaks produced the most acorns. I was also able to determine the oak ridges and oak flats that held the most prolific oak trees. That information was stashed away so when those red oak acorns drop this fall -- usually in late September to mid-October -- I'll already know the deer hunting hot spots.

Observant hunters know that red oak acorns were scarce the past few years. Yes, there were scattered areas with average acorn crops, but overall the nuts have been scarce. Since I know oak trees bearing abundant crops of acorns can be spotty, I checked my favorite oak ridges and flats carefully. Usually the oak trees with the large crowns, those receiving optimum sunlight, bear increased mast.

It's difficult to overemphasize the importance of acorns to wildlife. Deer will abandon nearly all other food sources when the nuts begin to drop. Black bears sometimes can't wait for the bounty and climb the oaks to feast on green acorns. Squirrels often do the same thing. Acorns are also a favorite food of wild turkeys. Find a woodland pond with oaks limbs overhanging the water and when acorns are abundant, so too will be wood ducks, waiting for a meal to splash into the pool. Ruffed grouse eat acorns, too. I've seldom found whole acorns in the crops of harvested grouse, but ruffs will gather along country roads and readily eat acorns bits produced when the nuts are crushed by passing vehicles.

There has been some confusion about the biology of acorns. Some hunters claim red oaks produce acorns only every other year, which is not true. To those hunters' defense I've seen that falsehood written in hunting magazines a number of times over the years. The truth is red oak acorns take two years to develop from flower to mature nut. Red oaks can, however, produce acorns every year. The acorns of white oaks (bur oaks are in the white oak family) form in the spring, mature during the summer and are shed in the autumn of the same year.

This difference in fruiting habits creates a sort of nutritional safety factor for wildlife. If a late freeze kills all the oak flowers in a certain area red oak acorns that began growing the previous year will be unaffected. Red oak acorns are missing the year after the freeze, but white oaks (bur oaks) fill the gap as long as freezing weather does not strike during the critical flowering period for two years running.

Acorn production is dependent on weather, overall health of the tree and other environmental factors. A viable tree will produce acorns every year, but on average an abundant crop will occur every two or three years depending on the tree and local weather conditions.

Remember that the abundant red oak acorns I observed last week were "set" the previous summer, so they were virtually unaffected by the late arrival of spring and this summer's cool temperatures.

If it seems too early to be thinking about acorns and hunting consider this: There will be roughly one minute less daylight tomorrow than there was today.

Bill Marchel, an outdoors photographer and columnist, lives near Brainerd, Minn.