On a cool day last week I took a stroll through the oak flats in several of my favorite local hunting spots. The temperature was in the 70s, the dew point was low and a moderate breeze kept the bugs from being a nuisance.

A comfortable day for man or beast.

I was scouting for deer, but not really expecting to see the deer themselves. Instead I went to survey the acorn crop, all the better for predicting where deer might materialize in the coming weeks and months when the mast begins to fall.

I used binoculars to scan the tree tops, which enabled me to determine which oak trees are producing the most acorns this year. Red acorns and bur oak acorns are easily visible this late in summer.

I found that most red oaks were barren of acorns, at least here in central Minnesota. This is a repeat of last year. Sure, some bur oak trees were heavy with mast, but most contained few or no acorns. I was also able to determine which oak ridges and oak flats held the most prolific trees. I've stashed away these observations for now, but when the bur oak acorns begin to drop — usually in late August through mid-September, depending on where in Minnesota a person lives or hunts — I'll use the information to identify deer-hunting hot spots.

I know that oaks bearing abundant crops of acorns can be spotty, so I checked the oak ridges and flats extra carefully. Usually the oak trees with the largest crowns bear increased mast, because they enjoy optimal sunlight.

It's difficult to overemphasize the importance of acorns to wildlife. I'm continually amazed by the number of hunters who don't understand the connection. Deer will abandon nearly all other food sources when the nuts begin to drop.

Other woodland creatures feast on acorns, too. Black bears sometimes can't wait for the bounty and climb the oaks to devour green acorns. Squirrels often do the same. Acorns are also a favorite food of wild turkeys, ruffed grouse and ducks. Find a woodland pond with oak limbs overhanging the water and you'll often find wood ducks waiting for their meals to splash.

There has been some confusion about the biology of acorns. Some hunters claim red oaks produce acorns only ever other year, a falsehood that has been repeated by several hunting magazines. The truth is that red oak acorns take two years to develop from flower to mature nut. However, white oaks produce an annual acorn crop. The acorns of white oaks (bur oaks are in the white oak family) form in the spring, mature during the summer, and are shed every autumn.

This pattern provides wildlife with a nutritional safety net. If a late freeze or other environmental factors kill all the oak flowers in a certain area, there's no need to worry about the red oak acorns. They began growing the previous year, so they probably won't be affected. Red oak acorns are missing the year after the freeze, but white oaks (bur oaks) can fill the gap as long as unfavorable weather doesn't strike for two consecutive years.

If it seems too early to be thinking about acorns and deer hunting, consider this: Minnesota's archery deer season is less than a month away. Find acorns now and be there when they fall. Deer and other wildlife certainly will be.

Bill Marchel, an outdoors writer and photographer, lives near Brainerd.