Why Woodpeckers Don’t Get Concussions

Years ago, Lois Nestel, the Museum’s founding director, wrote:

“I was stalking a pileated woodpecker whose calls and rapid fire hammerings seemed to come consistently from one area of trees not far from the house. These big, wary birds are not easy to pursue, so reasonable caution was necessary.

“Silence ahead seemed to indicate that the big bird had flown, but the apprehension was dispelled as, from a pine stub ahead, there came a staccato burst and bits of flying wood. A stealthy approach, timed with the pecking, ended abruptly when a large black beak topped by bright eyes and a flame red cockade was suddenly thrust around the side of the stub. With much scuffling of feet the crow-sized black body came into view. Unaware of being watched, the big bird seemed to talk to himself with soft knocking notes as if trying to decide where to drill the next hole.

Pileated woodpeckers have been increasing in numbers as we allow trees to get big and old. Photo by Emily Stone.

“Some unwary movement or sound on my part suddenly alerted him. There was a brief eye-to-eye confrontation; then the broad wings spread and with a few swooping beats bore the great woodpecker into the safety and seclusion of the forest.

“The pine stub bore evidence of much work. Large openings had been chopped through the shell and into the honeycombed interior. Breaking open a piece of this riddled wood revealed the dormant bodies of large black ants. This was what had attracted the woodpecker and would undoubtedly bring him back again. I might not be around to see, but the sound of drumming would bring to mind a clear picture of a great black bird with a flaming topknot—a memory to treasure.”

Lois’s experience with the woodpecker in the forest is timeless. How many of us have had the thrill of seeing or hearing these large birds swoop across the road, tear apart a backyard stump, or disappear into the forest? Actually, far more of us than in Lois’s day. Unlike many birds, populations of pileated woodpeckers have been increasing since 1966 due to the regrowth of large trees and the conversion of some large trees into food-rich snags. I’m sure Lois would be thrilled!

These days, during my own frequent encounters with pileated woodpeckers, I can think about the science behind the question I asked in the first chapter of my second book: “How can that little bird bang his head against trees all day and not develop debilitating headaches?”

Some of the initial research into this question, starting in the 1970s, proposed that areas of sponge-like bones in a woodpecker’s skull act as shock absorbers to protect the brain. Subsequent research, and logic, has disproved that. Pounding with a squishy hammer means that you have to pound harder to get the work done! Instead, newer research shows that a woodpecker’s muscles engage in a way that stiffens their body and transfers energy more efficiently. This seems to include exhaling with every bill strike—just the way I grunt to stabilize my core while picking up something heavy.

This female hairy woodpecker can pound away all day and not get a concussion. Several simple adaptations make that possible. Photo by Emily Stone.

When I wrote about pileated woodpeckers in February 2022, I was excited that some scientists had celebrated the woodpecker’s tongue as a brain-protector. Woodpeckers have a long tongue that wraps around the back of their skull. A Y-shaped bone called a hyoid apparatus supports the tongue and helps it extend into tree holes and extract insects for lunch. The researchers hypothesized that it also acts like a seatbelt for the brain. This was a fun “fact” to share with people!

After a neighbor suggested recently that I write about pileated woodpeckers again, I decided to see if there was any new research. Indeed! In 2024, James M. Smoliga of Tufts University School of Medicine summarized and critiqued the research on woodpecker brain protection. He criticized the hyoid seatbelt hypothesis for making conclusions based on preserved tissues with altered characteristics and the biomechanical properties of a human tendon. I will have to stop telling people that a woodpecker’s tongue cushions their brain.

Downy woodpecker with a sharp, stiff beak.  Photo by Emily Stone.

Smoliga concluded that, as far as current research shows, woodpeckers survive banging their heads against trees because they have less fluid in their brains than we do, which limits the “sloshing” of their brains within their skulls. And, in contrast to the impacts that cause concussions in humans or concussion-like symptoms in birds who have hit windows, woodpecker’s strikes are short, intentional, and involve coordinated muscle movement from back to front in a linear vs rotational way. The newest calculations, made with the most accurate modern technology, predict that a woodpecker would have to strike a tree twice as hard as usual to give themself a concussion.

Of course, any of these conclusions might be proven wrong or incomplete as scientists discover new information in the future. The beauty of science is that it requires us to be able to change our minds in light of new evidence. One thing that doesn’t need to change is the magic we feel, as Lois did, when we watch a great black bird with a flaming topknot spread their broad wings and with a few swooping beats disappear into the forest.

Emily’s brand-new third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.

For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Winter Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.