A Lifetime of Hammering Trees Might Affect Woodpecker Brains After All
A new study into the woodpecker brain shows proteins linked to CTE in football players, but it’s unclear whether birds suffer the same fate
Each timea woodpeckerdrums on a treeto find food, build a nest, or attract a mate, itgets hit withup to 1,400 g’s of force—14 times the amount that wouldtrigger a concussion in humans. Thankfully, the birdhas a few ways to dampen theblow: built-in shock absorbers, an enlarged brain case, and a specialized beak and skull that redirect pressure away from its head. As if that wasn'tenough, it canalso wrap its tonguearound the back of its headto serveas a cushion (when the organ isn't being deployed to trap dinner, of course).
These handy traits for concussion-heavy sports such as football and bike racing. The idea is simple: By modeling helmets and collars after abird that's built to headbang, outfitters can decrease the risk of chronic traumatic encephalopathy (CTE),which isin NFL players, as well asother brain diseases.
Or so the theory goes. While woodpeckers seem to fare okay in the long run, it's not known if their brains suffer from underlying damage.
“They’ve designed so much protective equipment based on the biomechanics of a woodpecker, but no one has ever looked at a woodpecker brain,” says Peter Cummings, a neuropathologist at the Boston University School of Medicine. “That just blew my mind.”
And so Cummings, a football dad himself, set out to change that. Heand hiscolleagues George Farah and Donald Siweksecured 10long-deceased woodpeckers (of different species) and five Red-winged Blackbirdsfrom two museum collections.They then took upscalpels and removed thin slices of the specimens’brains to test for depositsof an abnormal form of“t,”½ specific protein linked to neurodegenerative conditions such asCTE and Alzheimer’s.
The results, publishedin the journallast week, surprised them. “I was thinking that there’s no way these woodpeckers would develop neurotrauma,” Cummings says.But his analysis revealed damaged,“phosphorylated”clumps of the proteinin the woodpeckers’brains. Blackbird brains, on the other hand, had no such deposits.
Tau, like most parts of the nervous system, is complicated. Itcan protectthe passage of information between neurons, Farah says. But following repeated head trauma in humans, these proteins dislodge and accumulate in clumps that can slow the flow of information in the brain, resulting in cognitive and motor impairment. And that’s why finding similar buildups in the brains of woodpeckers—animals adapted to headbanging—was so unexpected.
These are birds, not humans, soyou can’t concludethat tau buildupis indicative ofinjury, let alone CTE.
But that doesn't necessarily mean thatwoodpeckers have brain damage. For starters, these are birds, not humans, soyou can’t concludethat tau buildupis indicative ofinjury, let alone CTE.
And then there’s evolution. Woodpeckers have been drilling into trees for 25 million years; if that was causing symptoms like memory loss—which presumably would reduce the birds’ fitness—theywould have shifted their behavior long ago.“Why would they still be pecking on trees if they are giving themselves neurodegenerative diseases?” Cummings says.
It’s also possible that the buildupsservean important function inwoodpeckers’ brains.“If you’re going to be jabbing your head into something at 1,200 g’s, you’d want the neurons to be able to jostle,” Cummingssays. “Could it be that this [build up of tau] has a neuroprotective effect?”
Without further research, Cummings’sguess is as good as yours (okay, maybe alittle better).But justas there’s a lot left to be learned aboutbird brains, there’s much to be done to understand how exactly CTE works. Woodpeckers, Cummings says, could help shed more light on both fronts.