For many years the theory that woodpeckers don’t get concussions from hammering away at wood was because the structure of the woodpecker’s skull and beak acts as a kind of built-in shock absorber, protecting the bird from injury.
Based on new research it may be that this is incorrect and that woodpecker heads behave more like stiff hammers than shock absorbers.
Some studies have shown that woodpeckers can hammer on trees as much as 12,000 times a day during their mating season, an average of between 18 to 22 pecks per second.
Some earlier studies, besides the shock absorber theory, revealed that woodpecker skulls boast thick muscles in the neck, sponge-like
bones, and a third inner eyelid to keep the eyeball in place, which scientists assumed would work together to absorb impact and prevent injury from the incessant drumming.
A study in 2011 found that there is also another springy structure in the back of the skull called a hyloid, which could work in concert with cerebrospinal fluid to further suppress vibrations. Most recently, a 2021 study posited that the bird's jaw apparatus might also act as a cushion during the pecking process.
Enter skeptics who did some more research. After analyzing more than 100 videotapes of three different types of woodpeckers, the researchers learned more. And one of the main reasons woodpeckers can hammer away is that their brains are smaller and lighter. (A human who slammed their head against a tree would quickly get a concussion.)
We hope to see more research about this topic in the future as it may help scientists to develop helmets or braces that can prevent concussions in humans.