Speaker 1: Welcome to brain stuff from how stuff works. A brain
Speaker 1: stuff is Christian zagger. Here. Despite how common North American
Speaker 1: tree squirrels are in many cities, neighborhoods, and outdoor spaces,
Speaker 1: a big misconception exists about these little critters. Tree squirrels
Speaker 1: store their food tree fruit like acorns in their nests
Speaker 1: or dens to snack on all winter. Here's the thing
Speaker 1: they actually don't do that. First, it's important to know
Speaker 1: that both the Eastern gray and Eastern fox squirrels dine
Speaker 1: on a varying menu of seeds, nuts, acorns, tree buds, berries, leaves,
Speaker 1: parts of pine cones, and other food some of us
Speaker 1: well we don't like to think about, like bird eggs
Speaker 1: and nestlings, and as well. You know they'll have the
Speaker 1: occasional slice of found pizza. Some of that stuff they
Speaker 1: eat right away, the rest they take to the nest
Speaker 1: or den for later. But when winter approaches, squirrels are
Speaker 1: faced with a challenge. They know instinctively that food sources
Speaker 1: will soon be scarce, so they gather all the food
Speaker 1: they'll need while also keeping themselves fed day today. That's
Speaker 1: why they're so busy in the fall. When Mother nature
Speaker 1: has made sure that all the acorns have fallen from
Speaker 1: the trees. Second, Eastern gray and Eastern fox squirrels are
Speaker 1: scatter hoarders, which means pretty much what it sounds like.
Speaker 1: They hoard their food and then scatter it in locations
Speaker 1: where they can easily access it. That's usually close to
Speaker 1: the tree holding their nest or den, but they often
Speaker 1: expand into areas of seven acres or two point eight
Speaker 1: hectic ers, and rather than leaving their goods above ground
Speaker 1: where other squirrels can steal them, they bury them, and
Speaker 1: this is called cashing about an inch maybe two point
Speaker 1: five centimeters under the soil, and squirrels are known to
Speaker 1: crack open a nut before burying it so they can
Speaker 1: keep it from germinating. When it comes time to eat,
Speaker 1: they forage for the nuts they buried. While squirrels possess
Speaker 1: a strong sense of smell, which allows them to sniff
Speaker 1: out nuts from under a blanket of dirt, researchers have
Speaker 1: long noticed evidence of strategic intelligence in the placement of
Speaker 1: their food. For instance, one study in two thousand eight
Speaker 1: reported that Eastern gray squirrels engage in what's called deceptive cashing.
Speaker 1: They dig a hole pretend to throw the acorn in
Speaker 1: while they hold it in their mouth. Then they cover
Speaker 1: up the empty hole and run off to another secret
Speaker 1: stash place. And they do this it was suggested to
Speaker 1: fool other squirrels who might be watching them. But a
Speaker 1: new study from professors in the Department of Psychology at
Speaker 1: the University of California at Berkeley and published in the
Speaker 1: September issue of the journal Royal Society of Open Science,
Speaker 1: claims that tree squirrels use a pneumonic technique called spatial
Speaker 1: chunking to sort out and bury their nuts scores by size, type,
Speaker 1: and perhaps nutritional value and taste now when they're hungry later,
Speaker 1: it's theorized they can remember where to find what they want.
Speaker 1: In other words, the squirrels put specific nuts in similar
Speaker 1: places to help them remember what nuts were where. I e.
Speaker 1: Almonds were placed in one general area, hazel nuts in another,
Speaker 1: and I guess pizza would go in a third area.
Speaker 1: This neumonic strategy has also been seen in rats. The
Speaker 1: finding researchers right in. The studies show that a scatter
Speaker 1: hoarder could employ spatial chunking during cash distribution as a
Speaker 1: cognitive strategy to decrease memory load and hence increase accuracy
Speaker 1: of retrieval. Squirrels have got a lot to think about.
Speaker 1: In other words, they need all the memory tricks they
Speaker 1: can get, so the next time you see a squirrel
Speaker 1: digging up a nut, know that she might have just
Speaker 1: found the exact one she was hoping for. Today's episode
Speaker 1: was written by Jamie Allen, produced by Tristan McNeil and
Speaker 1: For more on this and other topics, please visit us
Speaker 1: at how stuff works dot com.