BRAINERD — Last week’s cooler weather beckoned those who lean toward the outdoors, or at least got them thinking about it.

I took advantage of the comfortable temperatures to scout for acorns. What? Yep, with binoculars in hand I analyzed oak trees in a few of my hunting and photography locations. What I found was an average crop of red oak acorns will greet hunters — and the many critters that love to eat them — this fall, at least in central Minnesota. I discovered bur oak acorns are less abundant. Some bur oaks are bearing a fair number of acorns while others are barren.

During my forays I used binoculars to scan the tree tops to establish which oaks produced the most acorns as the acorns are still tiny. Thus, I was also able to determine which oak ridges and oak flats held the most prolific mast. 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 wildlife hot spots. Bur oak acorns drop earlier, the peak occurring in early September.

Observant hunters recognize red oak acorns were scarce last fall. Actually, they were basically nonexistent. Yet, last fall, bur oak acorns were extremely abundant.

It’s difficult to overemphasize the importance of acorns to wildlife, and I continue to see deer hunters who seem oblivious to that. 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 oak 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 occasionally find whole acorns in the crops of harvested grouse, but ruffs also will gather along country roads and readily eat acorn bits produced when the nuts are crushed by passing vehicles.

There has been lots of confusion about the biology of acorns. Some hunters claim red oaks produce acorns only every other year. That’s not true. To those hunters’ defense I’ve seen that false statement written in hunting magazines and talked about on hunting TV shows a number of times over the years. The truth is red oaks acorns take two years to develop from flower to mature nut. For example, the good red oak acorn this year was set last spring, but didn’t mature until this year (a two-year cycle). So, yes red oaks can produce acorns every year as long as the previous spring weather was favorable. 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 autumn of the same year (a one-year cycle).

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 kills the flowers, but white oaks (bur oaks) help fill the gap as long as inclement weather does not strike during the critical flowering period for two years running.

Acorn production is dependent on weather (a freeze during flowering is the worst), overall health of the tree and other environmental factors, such as humidity and even wind. A viable tree can 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, the relatively abundant red oak acorns I observed a few days ago were “set” the previous spring (2021) so they were virtually unaffected by the late arrival of favorable spring weather this year.

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

BILL MARCHEL is a wildlife and outdoors photographer and writer whose work appears in many regional and national publications as well as the Brainerd Dispatch. He may be reached at bill@billmarchel.com. You also can visit his website at BillMARCHEL.com.