Squirrels have been spotted organising their nuts by variety, quality, and even by their favourites, according to new research.
The study found the first evidence of squirrels arranging their nutty nibble booty using “chunking”.
“Chunking” is a cognitive strategy in which humans and other animals organise information into manageable categories, similarly to subfolders on a computer.
Fox squirrels can stockpile up to 10,000 nuts a year and can separate their caches by the types of nut they are storing.
“This is the first demonstration of chunking in a scatter-hoarding animal, and also suggests that squirrels use flexible strategies to store food depending on how they acquire food,” said study lead author Dr Mikel Delgado, along with psychology professor Dr Lucia Jacobs.
Presumably, sophisticated caching techniques maximise the squirrels’ ability to remember where they have stored their most prized treats while at the same time hiding them from potential pilferers, the researchers said.
“Squirrels may use chunking the same way you put away your groceries. You might put fruit on one shelf and vegetables on another. Then, when you’re looking for an onion, you only have to look in one place, not every shelf in the kitchen,” said Dr Jacobs.
The researchers gave squirrels 16 nuts in rows of four, for instance four almonds followed by four pecans, then hazelnuts and walnuts.
They gave other squirrels the same 16 nuts but in a random order.
Using hand-held GPS navigators, researchers mapped how the squirrels stored their caches of nuts.
They found that squirrels who foraged at a single location frequently organised their caches by nut species, and would keep each category of nut separately.
Squirrels that foraged in multiple locations deliberately avoided caching in areas where they had already buried nuts, rather than organising them by type.
“These observations suggest that when lacking the cognitive anchor of a central food source, fox squirrels utilise a different and perhaps simpler heuristic (problem-solving approach) to simply avoid the areas where they had previously cached,” the study concluded.