Do squirrels forget where they hide their food?

Is it true that squirrels forget where they buried about half of their food? While it’s almost certain that squirrels do indeed forget some subset of the nuts that they bury over a nut-burying season, it’s not clear whether these are truly forgotten or simply abandoned in favor of those that are easier to recover. Food storage is serious business, and squirrels don’t bury nuts randomly; they are organized, and they carry out a plan. This plan comes in one of two forms. Some squirrel species stash all their food in one place, a situation that is likely easier to remember than stashing in multiple places would be, but it is also riskier: the single cache may be discovered and eaten by another animal. Most squirrel species opt for a different strategy: they bury nuts in several spots across a general area. These species appear to have developed a system to help them remember where these caches are. It seems that squirrels are capable of “spatially chunking” (that is, placing nuts of the same type into caches that are separate from those belonging to another type). A 2017 study involving fox squirrels and four different types of nuts showed that the squirrels were able to sort the nuts and bury those of the same type together while burying those of the other types in separate caches a short distance away. So, while squirrels might forget where they bury some of the nuts they collect, the nuts that they do remember are likely well organized.