科學研究告訴你松鼠是如何找到埋藏的堅果的?

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.

我們人類有時會採用一種叫做“分塊記憶”的方法來記住某些東西。比如記電話號碼，我們通常會三位三位或者四位四位的去記。把七個數分成兩段來。

"Well, the way I think about chunking is it's any shortcutting strategy or mnemonic device that would allow an animal, be it human or otherwise, to increase their memory capacity and improve recall." Mikel Delgado, an animal behaviorist now at U.C. Davis.

米克爾·德爾加多是加州大學戴維斯分校的一名動物行爲學家。他表示：“我認爲分塊記憶是一種記憶捷徑或者說是幫助記憶的策略，這種方法可以讓動物和人類增加記憶的容量，並能提高記憶的能力。”

"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 recaching and redistribution of those nuts later, 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."

“我通過做研究，想驗證一下，松鼠是否會按照某種方法來收藏堅果類東西，這種方法有助於它們回憶起堅果放在哪裏或者對堅果進行分配或再分配，這有利於松鼠記憶堅果放的位置--因爲松鼠將相似類型或者相似價值的堅果存儲在差不多的位置。”

Delgado looked for this spatial chunking among 45 fox squirrels on the campus of U.C. Berkeley.

在加州大學伯克利分校，德爾加多嘗試在45只黑松鼠中探尋這種“空間分塊”。

"So we gave each squirrel 16 nuts…four each of four different types…so the types were almonds, hazelnuts, walnuts and pecans."

“我們給每隻松鼠16個堅果……每四個堅果爲一種類型……堅果的類型分別是杏仁、榛子、核桃和胡桃。”

"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."

“我們給松鼠第一個堅果後，它們會埋起來。我們會遠遠地跟蹤直到它不再跑，或者將堅果埋起來。我們記錄了松鼠埋藏堅果的位置。之後，我們將松鼠引到給它們第一個堅果的位置，並給它們第二個堅果，之後我們每一次都這樣做。”

"And so the other location condition was basically a lot faster and easier where we gave the squirrel the first nut, they buried it, and then we gave them the second nut right where they buried the first one."

“另外一種定位條件非常簡單快捷，我們給松鼠第一個堅果，埋掉堅果以後，我們就在它埋第一個堅果的位置那裏給它們第二個堅果。”

And when the squirrels got all their nuts from a central location, they spatially chunked them: "So they would actually cache nuts that were the same species in distinct areas from nuts of a different species…so the take home message I think for me is really that just like physical traits have evolved, I believe that cognitive traits have evolved as well. And a memory process that's very common in humans, this chunking, is a strategy that works for other species."

當松鼠獲得所有堅果時，它們已經對這些堅果進行了分塊的記憶：“松鼠會將同種類型的堅果和不同類型的堅果放在不同的地方。所以我覺得，就像身體特徵的進化過程一樣，松鼠的認知特徵也跟着進化了。分塊記憶--這種人類很常見的記憶策略，對其他物種也是適用的。”

The study is in the journal Royal Society Open Science.

該研究結果發表在《皇家協會開放科學》雜誌上。