November 20, 2023
As a green, high-school aged bowhunter growing up in the hilly farm country of Pennsylvania, I quickly learned that oak trees, and the succulent whitetail candy that rained from them each fall, were a key component to successfully filling my tag. Acorns contain critical nutritive and attractive components that lead to more daytime deer observations. It eventually dawned on me that if I scouted out the better acorn-producing trees, I would find something else scattered all over the ground: deer droppings!
Fruit of the Forest
The tree fruit (not a nut) is known as an acorn, pronounced “akern” if you grew up in the South. Acorns, also known as “hard mast,” are relished by many woodland wildlife species. Depending on the conditions Mother Nature throws at us, acorn production can be inconsistent, unreliable and cyclical. While astute bowhunters are aware of this, they also recognize that it’s a mistake to ignore acorns altogether.
If acorns had nutrition labels, they would disclose that the main reason for the attraction relates to the fact that they boast a high fat content that equates to maximum digestible energy. White oak acorns, widely considered the most attractive to whitetails, offer 8 calories per acorn, which is very high! Highly palatable and digestible, acorns are also very high in total digestible nutrients, a measure of food quality. In fact, acorns have more digestible nutrients than native browse and even corn and soybeans! Considering that, it’s no wonder even the ag fields can suddenly become devoid of deer when the oak trees are raining acorns onto the forest floor. That is exactly the kind of high-calorie diet deer need to prepare for the grueling breeding season and harsh winter weather that will follow.
Interestingly, some research has reported that red oak acorns have a higher fat content than white oak acorns. So, don’t write them off as a great location to hang a stand! It has been widely accepted that the acorns from the red oak species contain higher tannin contents, a phenolic compound that is bitter to the taste. However, it is important to keep in mind that there are many variables at play in nature.
While this all sounds great, just like anything in nature, relying on acorn production has its downfalls. It can take an oak tree roughly 30 years to produce acorns, depending on the species and stand quality. While all good deer managers and hunters understand the importance of offering diverse food sources, it’s hard not to think about the fact that your food plots can be productive in 30 days, not 30 years!
As a bowhunter, it’s important to capitalize on a good mast production year from oak trees. Research has shown that with white oaks, on average, you can expect to see two good mast crops out of a five-year period, whereas with the red oaks you can expect a good mast crop one year out of three or four years. Again, the key to maximizing habitat conditions for whitetails is to maintain diversity so your bowhunting success is never a function of a cyclical event that nature throws our way.
Red vs. White
As a bowhunter, you must learn to distinguish the two main groups of oak trees, red and white, and gain a little understanding about how they operate. You certainly don’t need to be a dendrologist (tree biologist), but there are a few basic principles that are easy to remember, and understanding them will help you become a better bowhunter.
There are many species of red and white oaks in the U.S., and the common species on the property you hunt will vary greatly with your geographic location. Start with basic tree identification by looking at the leaves. The leaves from white oak species have smooth, rounded lobes, while red oak leaves have pointed bristle tips.
Another distinguishing characteristic between red and white oak species is the time it takes each individual acorn to develop. This is a key distinction I find a lot of confusion around, even among fellow biologists. It takes two years for an individual (key distinction here) red oak acorn to develop but only one year for white oak acorns to develop.
While both red and white oaks flower in the spring, a red oak acorn forms and grows but doesn’t mature until the following summer. Red oak acorns drop during their second fall of development. On the other hand, all the acorns produced on a white oak flower mature and fall in the same year. Interestingly, red oak species can have two acorn crops, at different maturity levels, on the same tree at any one time. There is a fallacy that red oaks only produce every other year.
This is NOT accurate, and it implies that a red oak tree that drops its acorns in the fall of 2023 won’t be productive again until the fall of 2025. This is simply not true. The important point is that individual acorns from red oak species take two years to develop but an individual tree may have mature acorns dropping in the fall of 2023, with other acorns on the same tree developing and set to drop in the fall of 2024. If you’re a tree, living in a cyclical and unpredictable environment, this is a great way to spread out your exposure to less than desirable environmental conditions such as summer drought or late-spring frost.
Another interesting fact, and one I will discuss more in my October column, is that white oak acorns drop in the fall (October) and germinate that same fall, whereas the acorns of red oak species do not germinate until the spring or summer. Since white oak acorns germinate the same fall they drop, they are less available in the late winter and spring. A red oak acorn that drops in the fall and lays on the forest floor all winter, awaiting spring to germinate, is available as food for a much longer time.
Whether you know them as a-corns or a-kerns, we can all agree that when conditions are right for a boom year, a keen bowhunter can capitalize if he or she understands some basic oak ecology. Whitetails are imprinted on acorns during their first fall as fawns and, as a result, they are very aware of their high fat content and unbeatable digestible energy. The nutritional content of acorns can send whitetails into winter in peak condition, ready to take on the perils of a stressful breeding season and winter.
Next month, I’ll discuss the latest research on acorn production, how to scout your best-producing oaks and tie all the information in with how you, a bowhunter/deer manager, can enhance acorn production in your hunting area.