Acorns and squirrels just seem to go together, but do you know much about acorns themselves? There are a few good reasons that squirrels eat these particular nuts, and they even have a specific way to eat them.
Acorns are a great source of nutrients for both red and grey squirrels. Many squirrels prefer white oak acorns and eat them immediately while burying red oak acorns. This is because red oak acorns contain a higher tannin content than white oaks do, resulting in a slightly more bitter taste.
Below, we are going to dive into the important facts about acorns, why squirrels love them, how they eat them, and more! Curious to find out the difference between acorn varieties, or maybe why squirrels bury nuts? Stay awhile; we’ll get there.
What Is An Acorn?
So, what exactly is an acorn, really?
Known as both an oak nut and, more commonly, an acorn, this is a nut that has a single seed kept safe by a shell that is most often associated with the appearance of an acorn.
Made complete by the cap-like top, acorns are easily distinguishable and a common source of food for many woodland creatures. Not only squirrels enjoy this food source. In fact, acorns are edible for humans if processed properly.
More on that later, though.
Let’s first talk about the tannins that are in acorns by covering both what they are and how their implications are seen.
What Are Tannins in Acorns?
The word ‘tannin’ or ‘tannic’ is one you may have heard before, but not necessarily in relation to acorns. These terms are commonly referenced when it comes to wine and tastings.
In reality, tannins can be found in a wide variety of plants and nuts. For example, they are found in the skin of grapes, which then turn into wine. Have you ever eaten a grape that was extra bitter? The skin probably had above-average tannin levels.
The same goes for acorns, but on a scale that is much higher and can be dangerous. Whereas tannins might make wine unpleasantly strong in flavor, they also help to preserve the alcohol as it ages. Acorns do not have the same boozy advantage, and too many tannins will just result in poor flavor.
If these nuts are unpredictable, then why would squirrels want to eat them?
Why Do Squirrels Eat Acorns?
There are many types of nuts, berries, and other foods on trees in the areas that squirrels are typically located, so why acorns?
● Nutrition. Acorns are very nutrient-dense, notably a great source of potassium, vitamin A, and iron. They prove to be a great source of food for animals that do not eat large quantities.
● Abundance. Oak trees are incredibly widespread throughout many different environments, making acorns abundance through association. Where there is an oak, there is a food source.
● Easy to Procure. Acorns are small nuts, meaning that they are easy to gather and then carry among the branches of the tree. On the other hand, squirrels may wait for them to fall from the tree for an even easier procurement.
● Relatively Safe. While there are tannins in acorns, squirrels are experts when it comes to this common food source. Acorns are a relatively safe source of food due to their familiarity.
Do Squirrels Eat The Top of Acorns?
Squirrels do not tend to eat the cap of an acorn. In fact, the shell is not used for much either. When it comes down to it, the shell and cap of an acorn do not have nutrients that compare to that of the actual nut.
So, if a squirrel were to eat the shell and cap first before getting to the inside, actual source of food, it will fill itself up with empty plant material that does not supply it with the nutrients it needs.
How Many Acorns Does a Squirrel Eat Per Day?
Well, this one is a doozy. Just how many acorns do squirrels eat per day?
Squirrels have quite a process to go through when it comes to eating these acorns, so it is no wonder that they do not eat more than 2 or 3 nuts per day. This is not typically all they will eat, but acorns combine with other nuts, mushrooms, and berries as a source of food for squirrels.
Whereas berries and fungi are easily consumed, a squirrel must crack through the shell, remove the cap, and de-shell the acorn before it gets its meal. While this is worth the effort, thanks to the nutritional quality of acorns, it is certainly time-consuming for a squirrel.
The North Carolina Wildlife Resources Commission explains that when acorns and other tree nuts are plentiful in the winter months, more young will be born in the spring.
In years with less access to these food sources, fewer young will be able to be born because the female squirrels will not be as strong. Those who manage to survive the winter will often produce smaller litters.
It is for this reason, among many others, that squirrels bury nuts to store up for the cold, barren winter months.
Why Do Squirrels Bury Nuts?
So, why else do squirrels bury nuts if the ability to produce a new litter is not the sole concern?
The competition for acorns can be fierce, and burying (and then reburying, and then reburying again) acorns is a good way to keep their food safe from other squirrels and animals that might also be vying for some extra food.
Not only do they rebury acorns to keep other animals off their track, but they also do this for their own memories.
A well-hidden treasure trove of nuts is great, but if they don’t continuously shift locations, a squirrel might forget where its own stash is buried, let alone the stash of another squirrel.
Not to worry, though! If a squirrel loses its stash, those are just more oak tree seeds that are well dispersed and ready to grow into trees that are new sources of acorns! The circle of life, if you will.
What Kind of Acorns Do Squirrels Eat?
We always hear about squirrels eating acorns, but they must have a preference…right?
Right! Squirrels eat a variety of different acorns that come from different species of oak trees. So, which types of acorns do squirrels eat, and which of those are their favorite?
Squirrels Prefer White Oak Acorns
While different species of squirrels may prefer one type of acorn over another, white oak acorns and red oak acorns are the ones that come up most frequently.
In fact, research from the University of Maine shows that many squirrels tend to eat the white oak acorns right away while burying the red oak acorns that they find in similar areas. This is because red oaks contain a higher tannin content than white oaks do, resulting in a slightly more bitter taste.
By storing the red oak acorns for a later date, squirrels still ensure that they utilize the nutrition that the large red oak acorns provide while allowing some of the tannic acid to dissipate before they consume them.
However, white oak acorns also germinate faster, which leaves squirrels a shorter period of time to eat them before they go bad.
This indicates that maybe white acorns being the first choice has even less to do with preference and more to do with the sheer maximization of food sources.
Pros of White Oak Acorns For Squirrels
● Low levels of tannins, creating a less bitter taste
● Widespread and easy to find
● More nutritious than peanuts or other tree nuts
Cons of White Oak Acorns For Squirrels
● A bit smaller than red oak acorns
● Germinate quickly, so less time to be able to safely eat white oak acorns
Squirrels Bury Red Oak Acorns
So, squirrels have tastebuds, after all.
Squirrels prefer red oak acorns, just after white oak acorns, because they tend to be a bit larger and have fewer tannins than some other varieties. Essentially, this means that they inherit less of a bitter taste that characterizes some of the other acorns, even if white acorns happen to have even fewer tannins.
While these might be a second choice next to white oak acorns, they are still at the top of the list.
As we mentioned above, it might have to do more with survival instincts of eating the species that go bad more quickly and saving the ones that can survive until the winter.
If you’re interested in learning more, check out our piece on 29 Incredible Facts About Red Oak Tree here.
Pros of Red Oak Acorns For Squirrels
● Larger sized acorns for the same amount of de-shelling
● Widespread and easy to find
● More nutritious than peanuts or other tree nuts
Cons of Red Oak Acorns For Squirrels
● Higher levels of tannins, creating a more bitter taste
● The size of red oak acorns are larger than that of other species
All Other Acorns
While all acorns fall into two categories, red oak and white oak, there are so many different species within these distinctions.
Different species of squirrels may prefer different species of acorns that fall under the white oak acorn group when they need some food right away.
In the same vein, different species of squirrels may opt for specific species of red oak acorns to bury for winter in order to have their preferred source of food.
In a way, squirrels and their acorns are like humans who drink tea.
Someone may love green tea while another may enjoy black tea, but think that green tea tastes too earthy. Though both types of tea are relatively similar, we all have our preferences, and so do squirrels.
Are Green Acorns Bad For Squirrels?
Green acorns are a great source of extra tannins for any squirrels looking to bulk up. The flavor may not be great, in the same way, that acorns from other tree species than red oak are more bitter, but they will do the job when needed.
Green acorns are, in fact, not poisonous to squirrels. They will, however, create a negative mood shift in squirrels that consume a lot of them, thanks to the extra tannins messing with their typically amicable personalities.
4 Reasons Why Squirrels Eat Acorns
There are plenty of reasons that squirrels eat acorns, but here are four of the main draws of these oak tree nuts:
Acorns Provide Squirrels With Nutrition
Compared to some other types of nuts, acorns are extra high in nutrients—namely vitamins A and E, potassium, and iron.
Not only do these oak tree nuts have great vitamin and mineral content, but they are also a source of fat and protein. Acorns tend to be on the larger end of the scale when it comes to tree nuts, so the extra nutrients come in a large bundle.
Acorns Are In Abundance For Squirrels
Not only are oak trees the most well-known deciduous tree, but they are also one of the most abundant. If you are in an area full of deciduous trees, oak is most likely going to be the majority species, alongside others like maple, birch, and aspen.
So, take a moment to imagine you’re a squirrel. If you’re in a forest full of trees and need a meal, acorns will likely be one of, if not the very, most available type of tree nut you would find without putting much work in.
Acorns Are Easy To Procure For Squirrels
Speaking of not putting much work into gathering acorns, squirrels tend to have it easy when looking for these nuts.
While other animals might provide some steep competition, the acorns themselves are easy to locate.
Whether the acorns remain on the tree branches or they have fallen to the ground, they are easy pickings for a squirrel on the hunt.
Acorns Are Relatively Safe For Squirrels
Acorns may have tannins, but those are more of an issue to humans than they are to animals.
Squirrels may come across the inconvenience of a bitter taste or the unpleasantness of a negative mood swing, but that is the worst of it for these furry critters.
When all is said and done, acorns really are quite a safe bet for squirrels- from the knowledge that they are a secure food source to the ease of procurement and the benefit of the nutrients.
Can Humans Eat Acorns?
If prepared correctly, humans can, in fact, eat acorns!
You can take a look at our guide on 9 Amazing Fallen Acorn Uses here.
Acorns can be quite a useful resource, as seen in archeological studies, historical records, and practices of eating acorns that continue even today.
As far spread as oak trees are across not only North America but also other continents, it is no surprise that acorns have been utilized throughout history.
When it comes to processing acorns so that they are safe to eat, you’ll be surprised to find that the preparation is not as difficult as you might be expecting.
Before the processing truly begins, you’ll want to take a note from The Harvard Crimson and conduct a ‘float test.’ Essentially, acorns that float are either diseased or hollow due to rot, and those that sink are ready to move onto the preparation process.
First, you will make sure to remove the shell that gives acorns their well-known appearance, to find the nut that lies inside.
Following the de-shelling of the nut, you will want to break up the acorn into pieces so that it is not left as a whole nut.
Once the nut is broken up, the tannins inside will be more easily released. To release these tannins (or bitter plant compounds), soak the acorn pieces in water until the color darkens to look like a very dark tea (or a very light coffee.)
The process should take at least a week of changing the water numerous times to allow as much of the tannic acid as possible to be released.
Soaking acorns helps to release the tannic acid, which tastes bitter but can also be harmful.
Boiling is a commonly referenced practice but can actually trap in some of the bitter flavors. So, it is instead recommended to soak your acorns in any temperature water that is lower than boiling (yes, even hot water that is not quite at its boiling point.)
Once your acorns are processed, they can be ground into flour, roasted as a snack, or pounded into mush to produce oil.
There are even some recipes out there that you can try!
You can find acorn flour in the form of this Acorn Starch Powder, showing that this is not a practice reserved for those in remote areas or difficult situations.
Acorns happen to have many nutrients, good flavor once processed, and are abundant. Oh, another bonus, they are free if you harvest them yourself!
Hooray for Acorns!
Squirrels eat so much more than just acorns, but they get associated with these specific oak tree nuts so commonly because of the fact that squirrels do tend to favor them.
We hope this piece helps you to understand why exactly squirrels love acorns, how they choose them, and what they do with them.
Thanks for reading!
Mason, S. L. R. (1992). Acorns in human subsistence. University of London, University College London (United Kingdom).
Rakić, S., Povrenović, D., Tešević, V., Simić, M., & Maletić, R. (2006). Oak acorn, polyphenols and antioxidant activity in functional food. Journal of Food Engineering, 74(3), 416-423.