September 28, 2023
A cold, blustery wind tears through the hollow, soars up the hillside and cuts straight to the bone. Piles of fluffy, drifted snow blanket the landscape. It’s been a long deer season, but I’m still packing an Ohio buck tag, and deer are still traveling through the oaks. It’s been months since the acorn drop, but that’s just how vitally important these nuggets of nutrition can be.
The day wears on, and the sun dips below the horizon. Deer come out of the woodworks and begin moving all around my tree stand. First, some does. Then, a promising buck. After that, a great deer makes its presence known and walks right into bow range. A well-placed arrow later, the big 10-pointer with a split brow tumbles down through the oaks into the valley below. The 2021-22 hunting season comes to an end.
A TASTY TREAT
Acorns are among the most nutritious and tasty food sources in the woods. While they only have 6-8 percent protein, acorns are packed with nutrients, including 40-45 percent carbohydrates and 50-55 percent fats. These are very digestible for deer, making them an excellent food selection. There are lots of acorns produced, too. With mature trees, red oaks tend to produce an average of 20 acorns per branch, and white oaks produce about 15. Of course, these numbers vary by year, and range widely between mast crop failures and bumper crops. Factors affecting the acorn crop are rainfall, tree age, tree health and more.
Interestingly, massive mast crops tend to occur every three to five years. When these happen, average whitetail body weights can increase by 5-10 pounds. The opposite takes place during years of mast crop failure. As for timing, hot weather can cause an early acorn drop. Trees lose their acorns sooner in an attempt to conserve water. It’s also believed that extended droughts sometimes produce larger mast crops. Because trees are stressed, they produce more acorns as a species survival response.
High winds also cause trees to let loose of their prized nuts. If they fall too soon, and aren’t ripened, deer might not target them. That said, the tree species is more of a decider on the timing of the acorn drop than anything else. Each one tends to drop slightly earlier, or later, depending on its name.
THE VARIOUS SPECIES
All acorns fall into one of two groups: red and white oaks. These two families include approximately 90 subspecies in America alone, with hundreds existing worldwide. Nut production is the common thread between them, but even that varies. While white oaks produce a mature acorn every year, red oaks take two years to complete the same cycle.
As for the most common and important oaks, the red oak family includes black, cherry bark, live, nuttall, pin, red (northern and southern), sawtooth, scarlet, shingle, shumard, water and willow oak trees. The white oak family includes bur, chinquapin, overcup, post, swamp chestnut, swamp white and white oak trees.
There are numerous ways to identify oak trees, and to know which line of the family tree they belong to. Leaves are the easiest identifiers. While a few exceptions apply, members of the red oak family have pointed lobes with stringy, tasseled endings. White oak members have rounded ones without tassels. Bark composition can vary due to several things, including tree age, soil quality and more. Still, red oak subspecies commonly have darker, smoother bark. In contrast, white oak subspecies have lighter, rougher bark.
Acorns are also useful for identification. Generally, red oak acorns are shorter and broader, while white oak acorns are longer and narrower. Size and shape can also be influenced by environmental factors, though. There are other more subtle characteristics to look for as well. Canopy shape, tree height, branch structure and other things can help distinguish what subspecies it is, too.
Every oak species produces acorns, but these aren’t all the same. In fact, varying levels of tannic acid create a ranking of attraction to deer. Those with less tannic acid are sweeter and more targeted by whitetails. Species with higher levels are more bitter. White oak acorns have lower levels of tannic acid, making them sweeter. Red oak acorns are higher in tannic acid, which increases bitterness. Therefore, deer tend to target white oaks until these are depleted, and then move on to red oak subspecies.
Still, deer oftentimes target specific trees, even preferring one tree over another that’s of the same subspecies. While scientists don’t know for sure, there are several potential explanations. First, better soil quality might produce a sweeter, more desirable acorn. Secondly, the age of the tree might do the same. Also, other circumstances might apply, such as proximity to bedding cover, water sources or deer- to-deer social reasons. Some land managers also believe we have the power to boost attractiveness and output. Some think that, by fertilizing specific trees, deer are more likely to target these over other nearby options. All oaks considered, acorns can comprise more than 30 percent of a deer’s diet under normal conditions. However, when nuts are in great supply, that number can jump to as high as 75 percent. Deer are opportunistic, but still prefer variety in their diet.
THE GREAT SHIFT
The initial acorn drop is an excellent time to capitalize on the sudden shift in bed-to-feed patterns. While deer might have been primarily targeting green fields, such as crops and food plots, the woods are suddenly flush with carbs and fat. Deer recognize that and shift their habits accordingly. Rather than walking greater distances to reach destination feed fields, they hold tight to stands of producing oaks instead.
This creates the illusion of what some call the October lull. No, deer don’t move less during this period. Research shows the exact opposite. Whitetail movement (mature bucks included) gradually increases throughout summer and fall, and it peaks during the rut. It begins to taper off only after the post-rut arrives.
The perceived October lull is merely a change in movement, not a cancellation of it. Deer remain inside the timber not primarily because of hunting pressure, but due to changing food sources. Because oaks and acorns are generally closer to deer bedding areas, they don’t need to move as far to find food. So, they make it to open food sources, such as ag fields and food plots, later in the evening. Once acorns are depleted, deer begin hitting other food sources earlier and for longer periods.
HUNTING A BUMPER CROP
Deer hunting is all about intercepting lines of movement. In years of heavy acorn production, filling tags can seem daunting. A vast covering of acorns makes it much more difficult to hunt deer. The huge spread not only creates a massive pile of food, but it literally spreads deer out, too. Rather than being concentrated in fewer locations, they are scattered throughout the landscape, making it difficult to pattern deer or kill specific bucks.
Deer also don’t need to move as far to find food during heavy mast crops. They can rise from their beds, move 50 yards, slurp up some acorns and lay back down. This makes it more difficult to fill tags. During heavy mast crops, it’s crucial to brainstorm ways to get around this. For those who choose to be more aggressive, first consider walking the property while scanning the forest floor and glassing the canopy for the best and most abundant acorns. Keep your ears open for where acorns are falling, too. Then, move closer to bedding areas (if you can do so without alerting most deer).
A more reserved tactic is to focus on terrain, mainly spots that pinch or funnel deer movement. Potential spots include narrow strips of timber, fence gaps, draws, hubs, benches and more. And don’t forget about timing. In some cases, if your target is nowhere around, it might even be best to wait until the rut, so the deer are moving more. Or even the late season, once food sources begin to deplete. Regardless of whether you use passive or aggressive tactics, focus on white oaks first, and then shift to red oaks later in the season after the former nuts are gone.
Nut production aside, where can hunters find the various types of oak trees? It depends. Each subspecies has different environmental, sunlight, moisture level and soil type preferences. Some perform better in dryer conditions, while others do best in wetter soil, such as swamp white oaks. Know what you have on your hunting properties, where they are located, when they tend to drop and how much fruit they bear. Then, hunt accordingly.
HUNTING AN ACORN FAILURE
Some deer seasons produce the opposite of a bumper crop — a complete mast crop failure. During such years, deer don’t starve, but it can be difficult on them if other food sources aren’t abundant. Because the growing season carries deer until acorns drop, this is of little concern from April to September. However, to some extent, deer certainly rely on acorns from October to March.
So, what happens when this food source becomes limited? Fortunately, there likely won’t be a complete mast crop failure to where none are on the landscape. Generally, if a failure occurs, it’s limited to either red or white oaks, and the other continues to produce.
That aside, when acorn tonnage per acre decreases, deer must move on to other things. While it’s important to focus on hard mast, don’t forget about the softer varieties. These contribute to a significant portion of a deer’s diet, especially earlier in the season when soft mast predominantly drops. Focus on apples, crabapples, pears, persimmons and plums, to name a few.
Deer also rely on other food sources when acorns are scarce, such as native browse, agriculture and food plots. Browse is their primary food source during the colder months, and it’s even more critical during years with a decreased acorn crop. Digestible bark, buds, twigs, leaves and other woody foods are the most important category of a whitetail’s fall and winter diet.
So, if you see a limited number of acorns hanging in the canopy and expect a mast crop failure, put in some emergency food plots and pay attention to browse availability. You’ll not only help the deer out, but you’ll also experience some very good deer hunting.
The acorn drop is undoubtedly a very important part of a whitetail’s life. When available, they can live off these for months at a time. Understanding how that impacts deer, where it leads them and how it applies to your hunting efforts is extremely important. Time the acorn drop this season, anticipate sudden changes in whitetail lines of movement, pattern target deer and get it done. If it takes a while, no worries. The acorn drop is short, but the goods generally last throughout much of the season.