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5 Surprising Facts About Squirrels (Hint: They Make Jerky)

Right now, across much of the Northern Hemisphere, squirrels are doing what they do best: squirreling away seeds and nuts for the approaching winter. 

But there’s a lot more about these rodents that you might not realize. So we talked to Richard Thorington, curator of mammals at the Smithsonian Museum of Natural History, who presides over one of the world’s largest collections of the squirrel family, or Sciuridae. In all, the Smithsonian is home to more than 30,000 squirrel specimens.

A ground squirrel surveys its surroundings in the autumn tundra.
A ground squirrel surveys the autumn tundra in Denali National Park. Photograph by John Eastcott and Yva Momatiuk, National Geographic

Thorington started studying squirrels almost 50 years ago as a boy who just wanted to keep the varmints off his bird feeder. Since then, he’s co-authored two books on the subject, Squirrels: The Animal Answer Guide and Squirrels of the World, each of which probes the hidden lives of these seemingly everyday creatures and investigates their myriad roles across ecosystems. (See National Geographic’s squirrel pictures.)

Here are some of Thorington’s surprising squirrel facts:

Squirrels exist in nearly every habitat on Earth.

There are 285 species scattered across the globe, ranging from the half-ounce pygmy tree squirrels of western Africa to the nearly 20-pound (9-kilogram) gray marmots of Kazakhstan.

You’d basically have to venture to the planet’s Poles to escape them. (See video: “World’s Weirdest: Flying Squirrels.”)

Squirrels can help trees. 

Take the gray squirrel (Sciurus carolinensis) and its penchant for burying acorns for later use. A single gray squirrel can create several thousand buried caches of food each season, not all of which it can hope to rediscover. This is called scatter hoarding.

“In some cases the burying of nuts is good for the trees,” said Thorington.

“You have squirrels taking the acorns from directly underneath an oak tree and burying them somewhere else. That gives the trees more of a dispersal.”

Squirrels can hurt trees. 

In other cases, the relationship between squirrels and trees is less harmonious.

North American red squirrels (Tamiasciurus hudsonicus) and Douglas squirrels (T. douglasii) are seed predators that live almost entirely on the cones of conifer trees. They either eat the seeds immediately or store pine cones by the score in secret larders where the seeds remain moist and have little chance of germinating.

Obviously, this is great for the squirrels, because the preserved food supply allows them to survive the winter. The trees, on the other hand, lose their chance at reproducing.

Interestingly, a study published in 1995 in the International Journal of Organic Evolution showed that the trees may have ways of fighting back. The research revealed that in the Rocky Mountains, where red squirrels were prominent, the cones of limber pine trees had thicker seed coats and more resin.

“This makes it difficult for the squirrels to get between the pine cone’s scales,” said Thorington.

Watch video: “Squirrel vs. Hawk.”

But that’s not all. The researchers also found the cones had fewer seeds than normal and less energy per seed. So not only do the squirrels have to put in more work to access the pine cone’s innards, but they also got less of a reward for doing so.

Squirrels make mushroom jerky.

Perhaps one of the most intriguing things you’ll find in Thorington’s books are the lengths to which some squirrels will go to take advantage of a food source. (Also see “Squirrel Birth Control: To Stop Invasion, Science Gets Seedy.”)

For instance, did you know that some squirrels eat mushrooms? Not only that, but red squirrels will hang fungi out to dry between tree branches so that it keeps better over the winter.

Mushroom jerky is also less likely to infect their larder with insect larvae and nematodes.

Squirrels can “garden”—and know their food sources well.

Gray squirrels have also evolved a few rather impressive storage strategies. Thorington explained that the squirrels can tell the difference between red oak acorns and white oak acorns and store them accordingly.

Whites germinate quickly, almost as soon as they hit the ground, said Thorington, and the squirrels tend to eat them immediately since a germinated acorn loses nutritional value. Conversely, reds don’t germinate until spring, so the squirrels prefer to bury those for winter snacking. (See “No Nuts, No Problem: Squirrels Harvest Maple Syrup.”)

And now for the twist. A 1996 study in the journal Animal Behavior observed some squirrels biting through the embryo of white oak acorns, essentially paralyzing the seed’s ability to sprout. The squirrels then buried the modified white oak acorns as they would have with the reds.

What’s more, the scientists witnessed the squirrels digging up red oak acorns that they didn’t need to eat over the winter, nipping off their embryos, and re-burying the food for later use.

“It’s really interesting,” said Thorington. “If you watch squirrels, they are actually doing so much more than you might anticipate.”

If only humans were half as efficient with our leftovers.

Follow Jason Bittel on Twitter and  Facebook.

Comments

  1. Gary Oxford
    Jacksonville, Arkansas
    July 29, 1:23 pm

    How do knock a captured squirrel out so you can band him. Trying to Handel one, even with heavy gloves, will still get you bit several times.
    Gary Oxford

  2. Mary Connolly
    Florida ~~aka from Ny
    April 16, 9:30 am

    Hi
    I have lived with squirrels all my life = I was even Terrorized in my own home when he fell down the chimney and was trapped.
    Question
    How do I feed the birds and them together? They eat all the food and leave little for the birds.
    Thx
    Mary

  3. Elizabeth
    NE
    April 15, 10:20 pm

    Rodents (squirrels) and lagomorphs (rabbits) do NOT become infected with rabies. Opossums also cannot contract rabies. Their body temperatures are too low for the rabies virus to divide and multiple. If you don’t want squirrels on your roof, then trim your trees so they can’t jump onto your roof.

  4. Dawn
    Nova Scotia, Canada
    November 20, 2015, 6:33 pm

    This was so informative. Thank you.
    We found three mushrooms up in a tree while hiking today. It was peculiar and we thought maybe squirrels were drying them out but really had no idea. This help solve the mystery!

  5. Lucy
    September 14, 2015, 6:43 pm

    Cool, 1 I didn’t know that there was such thing as mushroom jerky and 2, I certainly didn’t know that the squirrels make it!!!!

  6. Wanda
    Portland, Oregon
    July 21, 2015, 11:29 pm

    Since March, One of our property trees was trimmed. I have been raising 4 boy squirrels from about 3 days old the Rehab people said. Currently this is month 5 and they all are successfully living in our backyard trees. A lot of work, but so worth it. I made a book with almost daily pictures of them and our food plan and the release into back yard. I was looking for any information on how to prepare for winter for them, just incase needed.

  7. Lauren
    Germany
    February 11, 2015, 11:27 am

    Thank you that was really intresting!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!=)

  8. John Schwendler
    Carlyle, IL United States
    January 31, 2015, 1:32 pm

    Several in our front yard trees, scurrying like crazy, faster than lightning, leaping from tree to tree.
    We scattered corn kernels by hand out of a bag, and they remain in the same spot two months later. We put out corn kobs we bought, and they get stripped within 24 hours. go figure.
    Funniest part is watching them clutch a vob to their chest and watch them roll around on the ground, like it is a toy.
    They take the largest leaves back up the tree for them.
    We had a spot of warm weather and an influx of probably confused birds, so I re-filled the bird feeder, which the squirrels won’t leave alone most of the year. They haven’t touched it. Interesting.

  9. Glen
    US
    December 13, 2014, 8:30 pm

    Christine – Squirrels can not carry rabies.

    They can bite and chew as you mentioned, so you shouldn’t try to pet or get too close to a squirrel you don’t know. Their claws are like tiny little razors, so even a friendly squirrel can unintentionally claw your skin up. They can also be sweet, gentle and playful and are incredibly soft.

    I certainly hope they don’t ruin the entire solar system though! 🙂

  10. Jason Bittel
    December 1, 2014, 11:12 am

    @Merlene: There are indeed white squirrels! Learn all about them! http://video.nationalgeographic.com/video/squirrel_white

  11. Merlene
    N.B. Canada
    November 26, 2014, 4:25 pm

    Mine is a question. are there any white squirrels?

  12. Susan Teays
    United States
    November 25, 2014, 4:53 pm

    I raised a squirrel from brand-new, blind baby. Murphy was a hoot. He was adopted by my sister and a year later recognized “mom” when I went for a visit. This, of course, was way before it was consiered illegal and immoral to raise abandoned baby critters.

  13. Lance Cole
    Rockies
    November 21, 2014, 3:06 pm

    American Gray and Fox Squirrels: Best served battered-and-fried, with buttermilk biscuits and milk gravy.

    This is just as environmental as the modern ‘insect diet’, but relies on rodents instead of insects (before someone screams ‘pity for the pretty little creature’, face it, it’s a tree rat).

  14. Christine
    Lakewood CO
    November 18, 2014, 9:22 am

    Squirrels can carry rabies, and they will bite.
    They can also ruin an entire solar system by chewing through the pipes and wires, chew through your roof, damage gutters.
    On the other hand, I’ve read that they are quite smart.

  15. Ikaika
    Virginia
    November 16, 2014, 6:45 pm

    Does anyone know what happens to the squirrels’ home and food storage when their tree gets cut down? I presume they look elsewhere, but I would think they would be surprised (hopefully not sad) and how would they eat in the winter if their hard work gathering acorns is gone?

  16. Tahoetraveller
    California
    November 14, 2014, 1:19 pm

    My daughter saved a newborn squirrel. Searched everywhere for into, got up every 2 hrs for weeks to feed. Taught Chi Chi to eat, poop, pee, and climb in trees. Had his first outdoor experience this week. She plans on releasing him after winter. I’m happy to have a grandsquirrel !

  17. Sam Ivory
    Grand Rapids, MI
    November 13, 2014, 11:30 am

    I LOVE SQUIRRELS!!!!!!
    (more then Katrina)

  18. Katrina Emory
    I can not say because I am 10 years old
    October 22, 2014, 5:35 pm

    I LOVE SQUIRRELS!!!!!!!!!!
    Are squirrels dangers

  19. Jasmine Syedda
    October 17, 2014, 9:16 pm

    intresting article! I never knew the little furry guys were so complicated!

  20. Israel Salvador Paucar Hernandez
    Lima Peru
    October 16, 2014, 1:34 am

    Congratulaciones.

  21. Israel Salvador Paucar Hernandez
    Lima Peru
    October 16, 2014, 1:33 am

    Hermoso Video. Y bellas publicaciones. Felicitaciones Mrs.

  22. Vincent
    China
    October 15, 2014, 6:06 am

    I haven’ t seen any squirrels before because I live in the city. I do met some squirrels in the zoo but there is a cage between me and the little guys. Thus, I have no idea that how bothering ther are.

  23. Anonymous
    October 15, 2014, 3:08 am

    This is really cool!

  24. Lynn Weiss
    Dallas, TX
    October 13, 2014, 11:13 am

    I trust nature. I’mini awe of nature, and I feel strongly that humans can learn skills, values, and balance from squirrels as well as many other animals. I’ve come to know these “truths” in my life through experience. It is good to become old with awareness.

  25. Harry B Brown
    October 1, 2014, 10:09 am

    They also will destroy a pecan crop. They can be very destructive!

  26. Janice D.Donnelly
    Manchester, NH
    September 28, 2014, 9:19 am

    I would think that red squirrels do not harm the potential new trees when they eat seeds because it passes through their digestive system and gets eliminated with fertilizer, as many wild animals do.
    Perhaps more of a study would be helpful.

  27. Jocelyne chambers
    frankford, ontario
    September 27, 2014, 7:44 pm

    We have learned to co-exist with our furry friends. When we first started to put out bird feeders, we thought that it was an “either or” situation. We`ve learned to allow the different species to coexist. Although I truly love all the bird species that abound in our area, I felt completely devastated this past spring when our “reds” disappeared. Come to find out that fishers were reintroduced in our area. Their effect was immediate and catastrophic. Luckily, our squirrel population has rebounded. We need to let “Mother Nature” do her own thing.

  28. Ima Ryma
    September 27, 2014, 4:47 am

    The most famous squirrel in the world,
    Rocket (Rocky) J. Squirrel, flyer.
    Through the T.V. air waves he hurled
    In flights of fancy not to tire.
    From Minnesota – Frostbite Falls,
    Snare drum major at Juilliard,
    Degreed at Calvin (Cal) Tech halls –
    Supermarket tech – ’twas quite hard.
    So highly educated, he
    Devoted life and limb and joke
    To warming hearts where cold war be,
    Shouting his tag line, “Hokey smoke!”

    Rocky liked collecting nuts, so
    Bullwinkle cracked up on the show.