How Do Squirrels Organize Their Nuts?

A new study suggests squirrels use memory strategies to remember where they put the good nuts. Find out more on BrainStuff.

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:02):
Welcome to brain stuff from how stuff works. A brain
stuff is Christian zagger. Here. Despite how common North American
tree squirrels are in many cities, neighborhoods, and outdoor spaces,
a big misconception exists about these little critters. Tree squirrels
store their food tree fruit like acorns in their nests

(00:24):
or dens to snack on all winter. Here's the thing
they actually don't do that. First, it's important to know
that both the Eastern gray and Eastern fox squirrels dine
on a varying menu of seeds, nuts, acorns, tree buds, berries, leaves,
parts of pine cones, and other food some of us
well we don't like to think about, like bird eggs

(00:46):
and nestlings, and as well. You know they'll have the
occasional slice of found pizza. Some of that stuff they
eat right away, the rest they take to the nest
or den for later. But when winter approaches, squirrels are
faced with a challenge. They know instinctively that food sources
will soon be scarce, so they gather all the food
they'll need while also keeping themselves fed day today. That's

(01:11):
why they're so busy in the fall. When Mother nature
has made sure that all the acorns have fallen from
the trees. Second, Eastern gray and Eastern fox squirrels are
scatter hoarders, which means pretty much what it sounds like.
They hoard their food and then scatter it in locations
where they can easily access it. That's usually close to

(01:32):
the tree holding their nest or den, but they often
expand into areas of seven acres or two point eight
hectic ers, and rather than leaving their goods above ground
where other squirrels can steal them, they bury them, and
this is called cashing about an inch maybe two point
five centimeters under the soil, and squirrels are known to

(01:56):
crack open a nut before burying it so they can
keep it from germinating. When it comes time to eat,
they forage for the nuts they buried. While squirrels possess
a strong sense of smell, which allows them to sniff
out nuts from under a blanket of dirt, researchers have
long noticed evidence of strategic intelligence in the placement of

(02:16):
their food. For instance, one study in two thousand eight
reported that Eastern gray squirrels engage in what's called deceptive cashing.
They dig a hole pretend to throw the acorn in
while they hold it in their mouth. Then they cover
up the empty hole and run off to another secret
stash place. And they do this it was suggested to

(02:38):
fool other squirrels who might be watching them. But a
new study from professors in the Department of Psychology at
the University of California at Berkeley and published in the
September issue of the journal Royal Society of Open Science,
claims that tree squirrels use a pneumonic technique called spatial

(02:59):
chunking to sort out and bury their nuts scores by size, type,
and perhaps nutritional value and taste now when they're hungry later,
it's theorized they can remember where to find what they want.
In other words, the squirrels put specific nuts in similar
places to help them remember what nuts were where. I e.

(03:21):
Almonds were placed in one general area, hazel nuts in another,
and I guess pizza would go in a third area.
This neumonic strategy has also been seen in rats. The
finding researchers right in. The studies show that a scatter
hoarder could employ spatial chunking during cash distribution as a
cognitive strategy to decrease memory load and hence increase accuracy

(03:46):
of retrieval. Squirrels have got a lot to think about.
In other words, they need all the memory tricks they
can get, so the next time you see a squirrel
digging up a nut, know that she might have just
found the exact one she was hoping for. Today's episode

(04:07):
was written by Jamie Allen, produced by Tristan McNeil and
For more on this and other topics, please visit us
at how stuff works dot com.