Squirrels use sophisticated technique to separate nuts by type, study finds

BERKELEY, Calif. — Some squirrels go a little nuts when it comes to sorting their acorns, a new study finds. Researchers at UC Berkeley observed the behavior of 45 nearby fox squirrels over a two-year period, finding that they use what’s known as a “chunking” behavior — organizing items into various smaller subsets in order to better manage the overall collection — to categorize their various nuts. 

This is notable because humans also use chunking techniques, although generally for storing information, whether the data is of a spatial, linguistic, or mathematical variety. Taking your email, for example, and dividing the messages into various folders could be considered a form of chunking.

Fox squirrels use this strategy to divide the nuts they gather over a year — between 3,000 and 10,000 — into what the researchers term “subfolders,” one for each type of nut.

“This is the first demonstration of chunking in a scatter-hoarding animal, and also suggests that squirrels use flexible strategies to store food depending on how they acquire food,” says lead author Mikel Delgado in a university news release.

The researchers believe that this idiosyncratic behavior allows squirrels to both remember where specific morsels are, and to hide other treats from animals that could steal them.

“Squirrels may use chunking the same way you put away your groceries. You might put fruit on one shelf and vegetables on another. Then, when you’re looking for an onion, you only have to look in one place, not every shelf in the kitchen,” adds Lucia Jacobs, the study’s senior author.

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These findings were discovered through the study’s principal experiment in which the squirrels examined were subjected to a variety of conditions relating to the locations and types of nuts provided. The authors provided the squirrels with almonds, pecans, hazelnuts and walnuts and monitored via GPS tracking where on the university’s campus the critters would bury their bounty during the two-year experiment.

To determine whether the way they were being fed mattered in the experiment, the authors gave some squirrels their nuts in organized rows of fours, while others were given them in a random order. Some were fed the nuts at the site where they last buried a nut, and some were fed at a fixed location.

The rodents, regardless of where they encountered or kept their nuts, were prone to separating them, even if they did so unconsciously.

“These observations suggest that when lacking the cognitive anchor of a central food source, fox squirrels utilize a different and perhaps simpler heuristic (problem-solving approach) to simply avoid the areas where they had previously cached,” the researchers conclude.

The full study was published last month in the journal Royal Society Open Science.

Comments

      1. Sir! Do you doubt the social value of knowledge such as the first name of Mayor McCheese? The home address of the Hamburglar??

        You do a disservice to higher education, sir!

      2. Ahhh you’re right! I need to go to a liberal re-education and sensitivity training center immediately!

      3. Hmmm…I think we need a $30 million study on which had the greater effect, the BO or the halitosis, don’t you?

      4. You just jealous because squirrels did this without having to get a 100K degree that you have and can’t use

      5. You’ve got a big mouth. Too bad your brain doesn’t match. However, I notice you’re a Bernie Sanders fan, an obvious indication that puddles of mush occupy your skull instead of a brain. Socialism sucks, Joe. MAGA.

    1. I’m only surprised if the squirrels aren’t members of ANTIFA, in which case no one at Berkeley would give them a second glance.

      1. AntiFA: Anti (F)irst (A)mendment. AntiFA are violent, book-burning, globalist, communist criminals.

    2. Yes, and cancer is still not cured and fusion power is still a dream and they spend money on this crap. Unreal.

      Bezerkeley.

      1. Bingo! Zillion other life saving uses for this money! How about how to build fireproof homes in tinder box forests? Or why we want to live in and near these forests ignoring the risks? How about helping the homeless get a life? Or pay for university pensions?!

        Or my favorite: Squirrel away some money for the next disaster! (couldn’t resist :-/ Oy vey. Seriously, is there anything we can do differently now that we know that squirrels are smarter than many humans?

      2. Yeah, tinder-dry cedar shakes on the roof – not smart. Maybe try sheet metal next time.

      3. Environmentalists could allow people to clear the brush away from the perimeter of their homes, but they believe the houses should burn.

      4. the homeless dont have to worry about a house fire. most homes burnt in the recent fires are insured, risk mitigated by that, hardly ignored. Many homes were not in nor even near a forest. yet they burned, it was fire storm not simply a forest fire. Umiversity pensions are hardly a life saving thing. Seeing as you dont lkke the university study, why do you want to pay university pensions?

      5. What, go back to compressed earth blocks reinforced with plastered geo mesh so that the structure is earthquake safe.
        With fireproof clay tiles or metal roofing. Never work. Too costly. Too expensive. Not code approved. Too energy efficient.

      6. The people who study the nut-hoarding patterns of squirrels for two entire years aren’t of the same caliber as medical researchers or physicists.

        The “Nut Studies students” are ‘special’.

      7. anyone staying in academia to do a study as a postdoc is “special”. You have to have a special kind of Asperger’s to get to that point to begin with.

    3. I don’t know about where they specifically store their nuts but as a person who has raised many squirrels I can without any tax payer funding tell you that squirrels can usually smell when acorns and hickory nuts have worms or bad meat in them even without cracking them open. And people often assume that because they have small brains they are stupid animals, they are actually extremely intelligent and just like every other living animal they each have their own personality.

      1. Many animals are intelligent. Probably more intelligent than the humans who believe they are products of evolution.

    1. This probably only got approved for grant money, because the researchers promised to deliver some tenous link to climate change. It’s the biggest running scam in the science research community.

      1. I will hereby end the climate change controversy: The climate changes. It always has, and always will. As for evidence of the contribution of human activities to climate change, the DFOM (Data Falsification And Obfuscation Machine) has yet to produce the hoped-for results.

        We are switching from 120 to 240 Volts to rev up the output before the world catches on to the hoax.

    2. Yes, and cancer is still not cured and fusion power is still a dream and they spend money on this crap. Unreal.

      1. I don’t care how much they spend on whatever they want as long is it isn’t my tax dollars. All research should be 100% privately funded with the lone exception of possibly related to national defense. If research is worth doing a private company will fund it, including medical research.

      1. Until cities made it illegal to hunt inside city limits people ate squirrels quite frequently. You haven’t ate until you try my grandma’s squirrel meat gravy and home made biscuits. Some restaurants still do: https://youtu.be/qBu4OqXG1tk

      2. Gordon Ramsay . A true butt faced tu rd who don’t give a s ht and will eat ANYTHING just because he can.

      3. Rats are perfectly clean/delicious if you raise and prepare them properly. Lobster was once considered ‘scum’, and look what people think of that now.

  1. So these observers think they’ve discovered something? Hey guys, it’s called SORTING, and people and animals have been sorting forever. Calling it “Chunking” doesn’t make it new, or clever, or even news-worthy for that matter.

      1. Licensed to kill squirrels by the government of the United Nations. A man, free to kill squirrels at will. To kill, you must know your enemy, and in this case my enemy is a varmint. And a varmint will never quit – ever. They’re like the Viet Cong – Varmint Cong. So you have to fall back on superior intelligence and superior firepower. And that’s all she wrote.

    1. We have a ton of squirrels in my yard, they sit in that Pecan tree and Chuck the shells at us. I wonder if they know that they chunk and chuck at the same time!

      1. Steve, don’t give them any new ideas. Another 600,000 thousand dollar study to study why squirrels throw empty nut shells at people. When I was a kid 40 years ago in my backyard a squirrel dropped or threw a bone fragment at me out of a full size maple tree. I always wondered if the bone was from another squirrel or something a squirrel brought up to its squirrel nest for the purpose of throwing a people or other animals. I promise to not go over 500,000 thousand with my tax payer study..

      2. I’m kind of a junk hoarder myself and kept the bone fragment. Where do I send it to find out what animal it came from?

  2. “The rodents, regardless of where they encountered or kept their nuts, were prone to separating them, even if they did so unconsciously.”
    How did they determine that the squirrels did this unconsciously?? Hope no tax money went into this “study”.

      1. I’m surprised the squirrels haven’t dragged off and buried half the student body. After all, a nut is a nut.

      2. Yes but squirrels can tell which are good and which are rotten inside with no hope of recovery. Vastly superior to liberal voters.

    1. Yeah exactly how do they know that squirrels don’t normally just hide the specific nut around the tree that it comes from and in this case they had to just default to a best guess of where their little squirrel imaginations thought each tree had to be?

  3. Has anyone studied the brains of those who engage in these utterly inconsequential studies? They claim, of course, that all knowledge is inherently valuable, but what price the present location of the fly on my window sill? To an entomologist, no doubt worthy of a $1 million government grant. Whoops! It moved. Need another $million to examine the stimulus-response. (I’ll take the $million. It was a fly swatter.)

  4. This is precisely why Willy Wonka used them to determine which nuts were perfect. Nothing new here.

  5. Wow! Berkley… How do you gather all of the squirrel info AND still have time to PROTEST as much as you do… I see the educational system isn’t wasted! LOL – LOL – LOSERS!

  6. This study was RACIST! Black squirrels should have been given twice as many nuts to make up for a lifetime of oppression by white squirrels!

    1. When I was a kid growing up in Bloomington MN 40 years ago we only had grey squirrels. 40 years later we now have full white and full black squirrels and I when I got home from work today I had several black, white, and grey squirrels in my yard jumping around and chasing and playing with each other. I love watching diversity in nature. If a full black and a full white squirrel were to mate would the offspring be grey? Another million dollar tax payer study?

      1. Well your neighborhood must be racist because there are no yellow squirrels with slanty eyes, nor are there brown squirrels that like to eat burritos.


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