This is Scientific Americans 60 Second Science. I'm Steve Mursky.

We humans sometimes use a memory technique called chunking.

For example, with phone numbers, we usually remember the three-digit chunk and the four-digit chunk, two items instead of seven.

Well, the way I think about chunking is it's any short-cutting strategy or

mnemonic device that would allow an animal be it human or otherwise to

increase their memory capacity and improve recall.

Michael Delgado, an animal behaviorist now at UC Davis.

And so in the case of the research I was doing in this study, I wanted to know if squirrels

would basically arrange their nuts in a way that might

facilitate either recall of the location or recashing and redistribution of those nuts later, like making it more convenient for them to remember where nuts were stored because they stored nuts of a similar type or value in similar locations spatially.

Delgado looked for this spatial chunking among 45 fox squirrels on the campus of UC Berkeley,

where she got her doctorate in August.

So we gave each squirrel 16 nuts for each of four different types.

So the types were almonds, hazelnuts, walnuts, and pecans.

And so we'd give the squirrel the first nut.

They'd go bury it. We would follow them from a distance until they had finished

caching or burying it. We recorded the GPS location where they'd buried the nut.

And then we lured them back to the original location

where they received the first nut

to give them the second nut.

And so we did that every single time.

And so the other location condition was basically a lot faster and easier where we gave the squirrel the first nut.

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