Ever wonder what birds do all day at your feeders? How can they go through that much seed? Have you ever seen them flying away with seed instead of eating it?
The answer is that birds use a behavior known as “caching”, which they typically do in the fall months. Many species begin hiding seeds to eat later in the season. Caching helps birds survive during bad weather and when food sources are at an all-time low. Caching isn’t as simple as it might appear. Not only do birds fly back and forth over hundreds of trips, they also have to remember where all the food is hidden. Most common North American feeder birds can have anywhere from hundreds to thousands of separate caches scattered about in their territory.
Adaptations and physical body changes help make caching possible. Some birds have a stretchy esophagus (Jays), or a pouch under or in front of the tongue (Nutcrackers and Crows), which helps the birds carry multiple food items at a time. In Chickadees the area of the brain responsible for memory actually increases during fall, or caching season. This helps them remember where the caches are.
On top of that, they also have to make sure their cache is not stolen by other animals. Studies in captive Jays and Crows have shown they are particularly good at this, making sure others aren’t watching while they cache their food. Some individuals are extra careful and may even re-hide seeds if they think another animal saw the hiding spot.
Caching also benefits other organisms. It serves as an important way to disperse and help forests stay strong. For example, some of the 100,000 seeds a year planted by a single Clark’s Nutcracker may germinate into whitebark pine trees. Some species like this rely heavily on bird caching for reproduction. Bird caches also feed other animals like mammals that dig up the food for themselves.
So, next time you are enjoying birds at your feeders pay close attention to where they go with the food. You may be able to see them caching that expensive seed. I enjoy this behavior in my woodpeckers. And in the spring I have little clusters of sunflowers that grow from forgotten Stellar Jay caches. A reminder of this wondrous bird behavior.
Source: Allaboutbirds.com, Cornell University 2021