Every autumn, a squirrel's brain grows by 15% to help it remember thousands of nut hiding spots.

Research conducted by scientists like Dr. Vladimir Pravosudov has shown that food-caching animals undergo significant neuroplasticity. In the autumn, the hippocampus of a gray squirrel can increase in volume by approximately 15 percent. This growth is driven by the birth of new neurons and the expansion of existing ones to handle the massive influx of spatial data.The hippocampus is the primary region for spatial navigation and memory in vertebrates. By expanding this area, squirrels can successfully manage 'scatter hoarding,' a strategy where they hide thousands of individual nuts across several acres. Studies indicate that a single squirrel can create between 3,000 and 10,000 caches each year with remarkable accuracy.This seasonal change is a highly efficient evolutionary adaptation. Maintaining a large brain requires a significant amount of metabolic energy. By shrinking the hippocampus back to its baseline size during the spring and summer when food is abundant, the squirrel reduces its daily caloric needs.The process is often triggered by environmental cues such as decreasing daylight and temperature changes. These signals alert the squirrel's endocrine system to prepare for the caching season. This cycle makes the squirrel one of the most prominent examples of adult neurogenesis in the animal kingdom.