As summer ends, leaves begin to fall from the trees and the winter’s chill envelopes the air, and wild animals need to prepare for the harsh months ahead. In these early autumn days, you may see birds flying around carrying foods such as seeds in their beaks. This is part of a behaviour called food caching.
Many birds collect foods such as seeds and nuts and put them in hiding places to find later on when food is more scarce. Birds can store hundreds of seeds a day and remember where they are months later. Chickadees and Titmice have larger brains in the winter to help them remember their food cache locations.
If you want to know more about food caching and how you can help, please read on.
What is food caching?
Food caching is a survival behaviour found in certain birds and mammals. It is a year-round activity for some, but for many, it is a seasonal one. Essentially, they collect foods like nuts and seeds and put them in hiding places to find later on when food is more scarce.
Birds usually push food into crevices in the ground or trees and use surrounding objects and soil to cover these hiding places. It is a strategy of hoarding food to ensure they have a constant supply over the cold winter months and to avoid competition from other animals.
Lots of time and effort is put into this activity, with some species working to store hundreds of seeds a day in different places and remarkably remembering where most are even months later.
Why do birds cache food?
For those who cache food seasonally, it is a tactic to enable them to survive harsh conditions in the winter months when food is scarce. It can also be useful for birds who would be at risk of being caught by a predator if they ate their food directly where they found it.
Scatter-hoarding is a specific caching behaviour involving hiding food in multiple locations. This works to stop other animals from finding their entire stock and accommodate minor environmental changes, such as trees falling or rain washing away the supply.
Which birds cache food?
Several species of birds cache their food in a multitude of fascinating ways. Chickadees, Nuthatches, Titmice, Jays, Woodpeckers and Shrikes all participate in caching behaviour.
Research has shown that for Chickadees and Titmice, their brain physically grows whilst they are food caching. The hippocampus, the part of the brain used for memory, actually gets bigger during autumn and winter, enabling these species to remember all the hiding spots for their food.
Other species that cache don’t necessarily have a physiological response like this and instead seem to cache within their territories to recover for later on.
Ravens and Scrub jays cache discreetly – behind structures or in shady locations – so that others can’t see where they’re hiding food, ensuring their hiding spots are known only to them.
Which foods do birds cache?
Nuts and seeds are the most popular items to cache as they are high in protein and fat and are less subject to degradation over time.
Chickadees cache black oil sunflower seeds. They usually eat a small amount and then hide the rest under bark, dead leaves, pine needles and in the ground.
Nuthatches cache heavier, shelled seeds like sunflower seeds. They hide them in tree trunks, the underside of branches, or under a shingle.
Titmice cache large seeds in bark, woodpiles and branches.
Larger birds like Crows and Nutcrackers are highly adapted to long-term caching, so they can carry lots of food in one go. Clark’s nutcrackers have been shown to carry up to an impressive 70 pinyon seeds at once.
Jay’s cache peanuts, sunflower seeds, acorns and pine nuts in the ground. It is thought that each adult blue jay will cache thousands of acorns, beechnuts and hazelnuts over the autumn season.
The Acorn woodpecker carries out a dynamic and complicated process of food caching. It collects acorns and places them in excavated cavities in a tree, one acorn per hole. However, as the acorns dry, they get smaller and need to constantly be moved to new spots that can hold them. The Woodpecker spends her time transferring these acorns around, ensuring they don’t fall out of the tree.
Shrikes take a rather sinister approach to food caching. Rightfully nicknamed ‘butcher bird’, the shrike caches its prey. They hunt small rodents, insects, and other birds with deadly, sharp beaks. They bring their kills back to their nests and hang them onto thorny branches for later consumption.
Eastern-screech owls also cache their prey. These owls store their prey in tree cavities and man-made structures like abandoned buildings. If their prey becomes frozen due to the low temperatures, they incubate it to thaw it out, deforesting it.
How can you help birds with their caching behaviour?
Food caching is a behaviour essential to the survival of many bird species, especially in the long winter months. Birds need a constant food supply to preserve many important physiological processes such as building body fat reserves, relieving stress and maintaining overall health.
Consider placing a foundation feeder in your garden filled with seeds and nuts to support local birds. Foundational feeders are ideally filled with food 24/7 so birds can ensure that they’ll have a reliable source of energy when visiting your garden.
Here is a list of some key ingredients to fill up a bird feeder with:
- Sunflower seeds: rich in essential protein and unsaturated fats
- Nyjer seeds: small black seeds that are rich in fat and oil
- Bread crumbs, cheese, rice and cereal: some foods that you’ve left over from meals can also be added to your feeder – just make sure they’re safe for birds to eat
- Water: add a little birdbath alongside the feeder for hydration
Especially during the winter months, keep a close eye on monitoring it to be sure there’s enough supply of bird food. You should probably expect to fill it up approximately every four days.
Check out this video on how to make a simple bird feeder for your garden: