The second and third installments of this Squirrel Series told us that squirrels are methodical in nut caching. The selection of which nuts to eat in the present and which to cache for the future is not random. They put thought into caching the nuts, considering factors like competition and the resource magnitude. Impressive work, squirrels.
Now, not to rain on the squirrels’ parade or anything, we ask are these skills actually useful? What good are these selection and cache processes if the caches go forgotten? This bring us to the question of the week:
To what degree do squirrels remember the location of their caches?
Well, talk about an age-old question. This definitely makes the list. For centuries people have sought an answer to such a burning question. For those of you in a rush, here’s the abstract: a squirrel’s memory depends on its surroundings.
A 1990 study by Lucia Jacobs and Emily Liman of Princeton University examined the accuracy of a squirrel’s memory in locating its cache of 10 hazelnuts within an area that held fellow squirrels’ caches, too. After delays of 2, 4 or l2 days, each squirrel was returned to the area and tested for its ability to retrieve nuts from its own cache site, which was amongst l0 cache sites used by other squirrels. Despite the caches being close, squirrels primarily retrieved nuts from their own caches. The study concludes that squirrels have a notable ability to remember their own caches, though they may also use their sense of smell to find nuts not from a specific cache.
A 2017 study by Mikel Delgado of UC Berkeley identifies a link between a squirrel’s cache memory and its competition. As competition increases, a squirrel’s ability to remember the location of its caches decreases. This makes sense. A squirrel will put less thought into (lol) remembering its caches if they are constantly pilfered. Alternately, less neighbors makes for a better memory for squirrels. These results are interesting in how they show that competition actually inhibits cognitive evolution rather than the perhaps expected opposite.
That’s some of the basic literature. I’m simply trying to convey that squirrels are not stupid. They are smart. Even when they forget their caches, they are doing it because they are smart.
