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Earth Science

There's a Logic To How Squirrels Bury Their Nuts ( 93

sandbagger shares an announcement from the University of California: Like trick-or-treaters sorting their Halloween candy haul, fox squirrels apparently organize their stashes of nuts by variety, quality and possibly even preference, according to new UC Berkeley research... Fox squirrels stockpile at least 3,000 to 10,000 nuts a year and, under certain conditions, separate each cache into quasi "subfolders," one for each type of nut, researchers said... Over a two-year period, the research team tracked the caching patterns of 45 male and female fox squirrels as the reddish gray, bushy-tailed rodents buried almonds, pecans, hazelnuts and walnuts in various wooded locations on the UC Berkeley campus...

Using hand-held GPS navigators, researchers tracked the squirrels from their starting location to their caching location, then mapped the distribution of nut types and caching locations to detect patterns. They found that the squirrels who foraged at a single location frequently organized their caches by nut species, returning to, say, the almond area, if that was the type of nut they were gathering, and keeping each category of nut that they buried separate. Meanwhile, the squirrels foraging in multiple locations deliberately avoided caching in areas where they had already buried nuts, rather than organizing nuts by type.

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There's a Logic To How Squirrels Bury Their Nuts

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  • by DontBeAMoran ( 4843879 ) on Sunday September 17, 2017 @06:49PM (#55215957)

    That's a really interesting resea - SQUIRREL!

  • Surely worthy of an Ig Nobel prize.
  • by Anonymous Coward on Sunday September 17, 2017 @07:16PM (#55216053)

    Cant cite a reference, but a local university where I live actually studied squirrels burying their nuts when they knew they were being observed vs. the opposite. It turns out squirrels, when knowing they are being watched will fake bury nuts and then move to another location and really bury the nut. Wilkes University- Wilkes Barre PA, Kirby Park squirrel study- an observation.

    • My dog will do the same thing, pretend to bury her bone then retrieve it when she thinks we are not watching and bury it somewhere else. It's pretty funny and cute to watch.

      • Why would this surprise anyone? We've known that animals (and not just mammals, either) can use logic for a while now.

        The notion that animals do not "think" is an artifact from the bad old days when it was widely believed that animals do not feel pain. []

        • I'm not really sure, people tend to underestimate animals. The dog I mentioned is now in her old age, diabetic and almost completely blind and deaf. A boat horn placed a few feet from her head doesn't even get a reaction.

          She's adapted. So long as you don't move any furniture, she gets around perfectly fine. You move something, she will run into it a few times and learn its position and continue to avoid that spot after you move the object. She doesn't even know who I am anymore when I go to visit until she

    • by MangoCats ( 2757129 ) on Sunday September 17, 2017 @10:14PM (#55216589)

      What the researchers did not uncover was the pattern of nut burying that the squirrels use to both store food and propagate the trees that bear the nuts. Over the course of millions of years, the squirrels and various species of trees have co-evolved to achieve an optimal re-seeding pattern by squirrel which protects the trees from both disease and wind damage.

    • Canada's "The Nature Of Things" TV documentary series, hosted by Dr. David Suzuki, covered this very topic of squirrel food hoarding behaviour in a 2012 episode called "Nuts About Squirrels": []

      The show highlights the work of Prof. Mike Steele and team at Wilkes, as well as that of Prof. Joel Brown at the University of Illinois, and Dr. Sarah Parton at Hampshire College.

      This new UC Berkeley research adds to a fascinating topic.

    • I was about to say the exact same thing.

      The even dig out stashes when felt observed by crows or other squirrels and burry them elsewhere.

  • I was feeding a ground squirrel p-nuts when I was camping. He would take them out of the shell and pack the nuts in his cheeks until both sides were full. He ran to his burro under a tree branch and then returned for more. This went on for 30 minutes.
  • For nuts associated with squirrels.
  • Cache Security (Score:5, Insightful)

    by mentil ( 1748130 ) on Sunday September 17, 2017 @07:51PM (#55216181)

    Let's say a competing species is able to smell almonds, but not other nuts. If all the almonds are separated into their own cache, then the competitor would only be able to sniff out the squirrel's almond cache, leaving their other nut caches safe. However, if they mix almonds in at all of their caches, then the competitor will smell the almonds in all of their caches, and thus find (and eat) all of their cached nuts. Separating the nuts thus prevents them from putting all their eggs in one basket, and the squirrel is less likely to starve because all its nuts were stolen. Those who sort their nuts survive and reproduce, those who don't die, et voila evolution.

  • by Anonymous Coward on Sunday September 17, 2017 @08:02PM (#55216217)

    They're not squirrels, they're tree rats. I fucking hate tree rat bastards, who are always stealing bird seed, chewing through wires, and making nests in attics. They are useless animals who lack intelligence and spend most of their lives stealing from bird feeders and taunting dogs. Tree rats are evil and deserve to be eaten by dogs or shot on sight. My hate is strong and I'm damned proud of it. In fact, my hate is getting stronger as I talk to you people. However, I'm not racist, and there's nothing racist about this post. I'm sure all the nutty tree rat lovers will use ad hominem attacks to justify their adoration of the disgusting rodents. It will prove that even they can't defend the evils of tree rats. And no, I'm not racist. I hate all colors of tree rats, whether they're gray, red, brown, black, or albino. They're all evil bastards that steal from respectable animals like birds and can carry rabies. They infest our college campuses, rummaging through the trash for scraps of food to sustain their miserable existence while pretending to act friendly around our young people. I hate tree rats with every fiber of my being. Tree rats should be shot on sight.

    Note to moderators: This is a parody of a copy-and-paste racist troll that frequently appears on Slashdot. It's unfortunate that I have to say this, but I intend this post to be funny. There really isn't anything racist about it, just an obsessive hatred of everything about tree rats. The author may or may not actually despise tree rats.

    • by Anonymous Coward
      I hate tree rats too, but the same ecological niche is occupied by monkeys in SE Asia. Those are worse. I fucking despise monkeys, cute as they are.
    • We have squirrels all over, none go in my attic, though they easily could if they wanted to. I guess they're happen enough with the huge ash tree in the back yard. Personally I think they're cute, we've even fed them. The skunks, OTOH, I hate them.

    • by PCM2 ( 4486 )

      Coincidentally, when my sister moved to Texas she was horrified to discover she had a huge colony of rats living under her back porch, and needed to call "the Rat Man" to have them removed. Her neighbors assured her this was all par for the course in that area. The Rat Man concurred ... adding, however, that if the infestation had been squirrels he would have advised her to sell the house. Too damaging, too hard to get rid of for good.

  • What sorting algorithm do they use? Bubble sort?
  • by Zanadou ( 1043400 ) on Sunday September 17, 2017 @09:01PM (#55216399)

    ...male and female fox squirrels...

    Thanks. I'd been wondering how that worked.

  • by hyades1 ( 1149581 ) <> on Sunday September 17, 2017 @09:17PM (#55216453)

    "Like trick-or-treaters sorting their Halloween candy haul, fox squirrels apparently organize their stashes of nuts by variety, quality and possibly even preference..."

    My buddy used to date a girl like that.

    • by Anonymous Coward

      Did she have cute little ears and a bushy tail? If so, I think your buddy and my Buddy are the same dog. He really loved to chase her around the yard, and she'd always wave her tail at him coquettishly and then call to him from the trees. It was a forbidden romance, but Buddy had it bad for her.

      I can't blame him for trying though, since we took his nuts away when he was just a puppy.

    • I'm confused ... she stashed his nuts? At different places?

  • Google will go tree by tree with sonar or even x-ray equipment to categorize every nut and target the squirrels better.

  • the caching patterns of 45 male and female fox squirrels as the reddish gray, bushy-tailed rodents buried almonds, pecans, hazelnuts,walnuts and leftover pizza in various wooded locations on the UC Berkeley campus...

    ftfy. This IS UC Berkeley afterall.

  • by Slugster ( 635830 ) on Sunday September 17, 2017 @10:34PM (#55216645)
    In the midwest-US, the gray squirrels are,,,,,, uh,,,, not that sophisticated about things.

    1. When they bury a nut, they immediately urinate on the spot. IF they ever managed to find the [whatever] again, this would be the way I would have guessed that they were doing it. And-

    2. Often a blue jay or other larger bird will follow a squirrel around, wait until it buries a nut and takes a couple hops away, and then the bird will dig up the nut and eat it. As the squirrel watches. And the squirrel (standing literally a foot away) doesn't seem to be able to mentally connect the significance of these two sequential events.

    I've seen the local squirrels in the yard "feeding the birds" lots of times.
    There's not always a bird--but even so, I don't know that I've ever seen any squirrel recover anything it buried.
  • I studied wildlife biology at UC Berkeley, and even had to do some work with squirrels. This study is interesting, but I'm very glad to have not been responsible for tracking those squirrels and studying their caches of nuts.
  • Knowing this information. Who the hell cares!
  • Sometimes you feel like a nut, sometimes you don't []

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