• ljmarkson

The Squirrel and Acorn Connection

Updated: Dec 11, 2021

I wish I spoke Eastern grey squirrel on a warm day a couple weeks ago when I saw an industrious young squirrel think he was cleverly burying prized acorns in the planters on my deck. A wily chipmunk was following him and a few minutes later dug them up and stuffed them in his cheeks to bring back to his den. I watched this scenario play out multiple times throughout the day for a few days in a row. Out of curiosity I did a bit of surfing on squirrels and acorns and found out a few fun tidbits that I didn’t know, including a visually adult one about a part of the male anatomy that was named after the acorn.

These photos were taken just minutes apart! The squirrel buried the acorns and the chipmunk dug them up!

Not All Acorns are Equal There are 32 species of oaks in North America, but squirrels are fairly picky about what acorns they like and how they bury them. There are many complex contributing factors! The acorns from the white oak family (white oak, swamp white oak, chestnut oak, bur oak, chinquapin oak…) are the tastiest. The red oak acorns (red oak, scarlet oak, pin oak, willow oak, black oak…) are nutritious but intensely bitter even to wildlife not because they have more tannin in them which they do, but because the tannin in red oak acorns breaks down in saliva so the bitterness is more obvious. This does not happen with white oak acorns where the bitterness is not as noticeable. Squirrels will eat about 85% of the white acorns and bury 60% of the red acorns they find. The white acorns also sprout in the fall and are more perishable if buried. Red acorns are keepers because other animals don’t like them much so there’s less chance of pilfering, and they don’t germinate until the following spring. Grey squirrels breed in late winter (and late summer) and their ability to conceive and raise young is dependent on food resources. Having a well-stocked supply of buried acorns in winter is essential for the next generation of squirrels.

The baby squirrels in this nest from early last spring became the parents of the baby squirrels in the nests made in late summer...and their babies are the young squirrels I've been "helping" a bit with foraged nuts this fall. Only 25% of squirrels make it the first year.

Acorns are Not Just Food for Squirrels There is evidence humans have practiced balanophagy, or the practice of eating acorns, since the stone age. Acorns are becoming increasingly popular with survivalists, urban foragers, sustainable food advocates, and as a gluten-free alternative to wheat flour. They need to first go through a process of being soaked in water to remove the bitter tannins before using for food though. Once I became more focused on acorns, I noticed very pricy packages of acorn flour at the farmers market.

I don't have many overstory trees, including mature oaks, so I'm an urban forager not for myself but for the squirrels and wildlife in my yard! During fall dog walks I fill empty dog bags with sidewalk nuts.

Squirrels Shake Each Nut They Find Like the “eggdicator” in Willy Wonka, squirrels are “nutdicators” and can decide if a nut is a good or bad one. They prioritize after carefully shaking them. Researchers found this out by slowing down footage of squirrels with nuts! If nuts have weevils in them or are damaged in some way, squirrels immediately eat them.

These cracked and holey nuts wouldn't pass muster to be buried by squirrels. They would undoubtedly be eaten on the spot, bugs and all!

Squirrels bury the "good" nuts they find because they are more likely to be viable food sources later in the winter.

These hickory nuts and acorns appear flawless to me, but I'm not capable of knowing if they would be worthy of being buried by picky squirrels!

Squirrels are Intentional About Where Their Nuts are Buried

It’s amazing how many studies have been done about the nut collecting and burying behavior of squirrels! In general, how abundant the nuts are dictate the location of the nuts buried, with multiple variations on the subject. When other squirrels are around even if there are plenty of nuts or if there is a scarcity of nuts, squirrels bury the nuts farther away. The interconnected relationship between squirrels and the oak tree is just as fascinating. Squirrels burying nuts farther away will also increase the survival rate of the oak species because they are less likely to be eaten and any oak seedlings that sprout won’t be shaded out by the parent tree. To keep the two sets of young squirrel siblings visiting my front and back yard close to home where it is safer for them, this fall I collected and scattered half a dozen heavy brown lawn bags full of acorns from a friend who can't keep up with the acorns dropping on her patio and porch from a 100-year-old oak overhanging her home.

So many acorns leave my neighborhood for landfills that when I scattered six lawn bags full of acorns around my yard they disappeared within a week thanks to busy squirrels and chipmunks.

Squirrels Really Do Know Where They Bury and Rebury their Nuts Squirrels ensure food for when they need it by “scatter hoarding” thousands of nuts in various locations. If other squirrels are around, they have been observed to cleverly fake them out by pretending to bury nuts, then scampering off somewhere else to really bury them. They will also dig up and rebury their nuts. Different studies don’t always come to the same conclusion, but recent research indicates squirrels have a 95% nut retrieval rate and use spatial memory and not necessarily smell to remember where they bury nuts.

This energetic young squirrel spends his days burying thousands of nuts, and apparently remembers where most of them are!

Squirrels Need LOTS of Nuts to Survive Squirrels needs to eat the equivalent of their own weight weekly. They will work relentlessly to make sure they have nuts in lean times and can collect and bury up to 50 nuts an hour during high nut season! There is a natural and complex relationship between the yearly acorn crop and ebb and flow of the squirrel population, particularly in the years following an overabundance of acorns in what is called a mast year. Wildlife, including chipmunks, rabbits, opossums, blue jays, and more than 100 U.S. vertebrate species also rely on acorns as a food source. I can’t help wondering how disruptive it is to the ecosystem of my semi-urban area to have tons of acorns bagged and taken away as yard litter.

If I look around my yard in the evening, I'm likely to find squirrels eating nuts. I like to imagine this is their way of finishing off a long day of burying nuts!

Eastern Chipmunks Are as Common and Mysterious as Squirrels

The wily chipmunk digging up the unobservant squirrel’s nuts on my patio was preparing for semi-hibernation by stockpiling nuts in his den to eat if needed throughout the winter. The hibernating behavior of chipmunks in Georgia seems as complex as the collecting and burying of nuts by squirrels. Chipmunks don’t hibernate all winter but go in and out of hibernation which is why I may not see them for weeks then might see them scampering around collecting food on a sunny warm winter day.

This little guy left the planter with his cheeks full of acorns!

Squirrels are not as concerned about others taking their nuts as they are about competing for the nuts they gather, which is why the squirrel wasn’t focusing on the chipmunk following him. He obviously thought burying his best nuts in my planters, which are a bit of a distance from where he found them, would ensure he’d have them later in the winter. I’ve said before that I try my best not to interfere with backyard wildlife unless to compensate for what is going on in my neighborhood. Again, I wish that I spoke Eastern grey squirrel because I would tell the ones visiting my yard not to panic too much about food sources in late winter when they’re ravenous and starting their family. I’ll supplement them a bit to get them through to the spring to make up for all the acorns that have been carted away to a landfill by the truckload.

This dirt covered squirrel just finished furiously burying acorns in my planter. He seemed more focused on the task at hand than looking around for the acorn stealing chipmunk that was following him!

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