169 — Tau accumulations in the brains of woodpeckers

I’ve always wondered why woodpeckers — whose brains experience huge shifts in acceleration while they’re pecking — don’t suffer from debilitating brain damage. In fact, hummingbird skulls have been used to design football helmets, under the assumption that something about this structure reroutes mechanical stressors in a brain-friendly way. In truth, all of this research was based upon the unsubstantiated findings of a paper published in 1976 that examined two birds.

This paper suggests that woodpeckers likely do suffer from some amount of brain damage: Tau accumulations, seen also in diseases like chronic traumatic encephalopathy (CTE) or certain types of dementia, appeared in almost all of the ten woodpecker brains studied in this paper. (These accumulations were identified using silver-staining, which stains tau accumulations more vividly than the surrounding tissue.)

The accumulations were “perivascular,” meaning they arose near blood vessels, similar to where we expect to see tau accumulations (in the depths of sulci) in human brains with CTE.

Because the number of subjects was so small and staining was likely incomplete, it’s difficult to say for sure whether this suggests that birds do indeed suffer from traumatic brain injury during pecking. But it certainly opens the previously-closed door for further research into both tau accumulations as well as using woodpecker skulls as a model for safety gear.