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Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,

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Speaker 1: Lauren foc Obam here with another classic episode from our

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Speaker 1: former host, Christian Saga. If you've ever watched squirrels going

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Speaker 1: about their squirrel business, you may have wondered whether there's

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Speaker 1: any method to their for lack of a better term,

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Speaker 1: nut madness. It turns out they're very well. Maybe a

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Speaker 1: brain stuff is Christian Saga here. Despite how common North

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Speaker 1: American tree squirrels are in many cities, neighborhoods and outdoor spaces,

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Speaker 1: a big misconception exists about these little critters. Tree squirrels

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Speaker 1: store their food tree fruit like acorns in their nests

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Speaker 1: or dens to snack on all winter. Here's the thing

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Speaker 1: they actually don't do that. First, it's important to know

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Speaker 1: that both the Eastern gray and Eastern fox squirrels dine

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Speaker 1: on a varying menu of seeds, nuts, ache horns, tree buds, berries, leaves,

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Speaker 1: parts of pine cones, and other food some of us

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Speaker 1: well we don't like to think about, like bird eggs

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Speaker 1: and nestlings, and as well, you know they'll have the

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Speaker 1: occasional slice of found pizza. Some of that stuff they

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Speaker 1: eat right away. The rest they take to the nest

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Speaker 1: or den for later. But when winter approaches, squirrels are

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Speaker 1: faced with a challenge. They know instinctively that food sources

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Speaker 1: will soon be scarce, so they gather all the food

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Speaker 1: they'll need while also keeping themselves fed day today. That's

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Speaker 1: why they're so busy in the fall, when mother nature

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Speaker 1: has made sure that all the acorns have fallen from

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Speaker 1: the trees. Second Eastern gray and Eastern fox squirrels are

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Speaker 1: scatter hoarders, which means pretty much what it sounds like.

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Speaker 1: They hoard their food and then scatter it in locations

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Speaker 1: where they can easily access it. That's usually close to

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Speaker 1: the tree holding their nest or den, but they often

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Speaker 1: expand into areas of set been acres or two point

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Speaker 1: eight hectic ers, and rather than leaving their goods above

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Speaker 1: ground where other squirrels can steal them, they bury them

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Speaker 1: and this is called cashing about an inch maybe two

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Speaker 1: point five centimeters under the soil, and squirrels are known

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Speaker 1: to crack open a nut before burying it so they

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Speaker 1: can keep it from germinating. When it comes time to eat,

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Speaker 1: they forage for the nuts they buried. While squirrels possess

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Speaker 1: a strong sense of smell, which allows them to sniff

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Speaker 1: out nuts from under a blanket of dirt. Researchers have

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Speaker 1: long noticed evidence of strategic intelligence in the placement of

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Speaker 1: their food. For instance, one study in two thousand eight

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Speaker 1: reported that Eastern gray squirrels engage in what's called deceptive cashing.

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Speaker 1: They dig a hole, pretend to throw the acorn in

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Speaker 1: while they hold it in their mouth. Then they cover

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Speaker 1: up the empty hole and run off to another secret

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Speaker 1: stash place. And they do this it was suggest it

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Speaker 1: to fool other squirrels who might be watching them. But

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Speaker 1: a new study from professors in the Department of Psychology

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Speaker 1: at the University of California at Berkeley and published in

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Speaker 1: the September issue of the journal Royal Society of Open Science,

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Speaker 1: claims that tree squirrels use a pneumonic technique called spatial

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Speaker 1: chunking to sort out and bury their nuts scores by size, type,

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Speaker 1: and perhaps nutritional value and taste. Now when they're hungry later,

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Speaker 1: it's theorized they can remember where to find what they want.

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Speaker 1: In other words, the squirrels put specific nuts in similar

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Speaker 1: places to help them remember what nuts were where. I e.

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Speaker 1: Almonds were placed in one general area, hazel nuts in another,

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Speaker 1: and I guess pizza would go in a third area.

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Speaker 1: Thisnemonic strategy has also been seen in rats. The finding

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Speaker 1: researchers right in the studies show that a scatter hoarder

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Speaker 1: could employ spatial chunking during cash distribution as a cognitive

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Speaker 1: strategy to decrease memory load and hence increase accuracy of retrieval.

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Speaker 1: Squirrels have got a lot to think about. In other words,

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Speaker 1: they need all the memory tricks they can get. So

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Speaker 1: the next time you see a squirrel digging up a nut,

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Speaker 1: know that she might have just found the exact one

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Speaker 1: she was looking for. Today's episode was written by Jamie

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Speaker 1: Allen and produced by Tristan Neil and Tyler Clang. For

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Speaker 1: more on this than lots of other topics, visit how

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Speaker 1: stuffworks dot com. Brain Stuff is a production of by

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