Fall might be a time for humans to slowdown from a busy summer and snuggle up inside to stay warm and dry. But for many animals, fall is a season of intense preparation for the impending winter. Some species migrate, and some hibernate. Some grow a warm winter coat, and some grow their brains.

Yes, you read that right, the brains of chickadees grow in the fall, right around the time when they have a whole lot of remembering to do. For non-migratory northern resident birds, food storing is an essential seasonal behavior occurring during a time of year when invertebrate food is scarce, and seeds and nuts are quickly vanishing. The energetic chickadees gather and cache seeds in hundreds of hiding places in trees and on the ground, distributing small stashes in many places to assure not all is lost in one big theft. When winter comes, they need to be able to find what they’ve stashed.

To locate their caches, chickadees rely on highly specialized spatial memory abilities. The hippocampus, the part of the brain responsible for spatial organization and memory, expands in volume by approximately 30 percent by adding new nerve cells. This change in size is correlated with seasonal food-storing patterns.

Their weighty minds eventually become a hinderance for their airborne ways, so when spring arrives and these winter memories are no longer needed, the chickadee’s hippocampus shrinks back to its normal size.

 Elastic brains are another amazing adaptation to add to the long list of unique survival strategies observed in birds.