Does all that hammering hurt woodpeckers’ brains?

A woodpecker’s head takes a lot of pounding. In its lifetime, a woodpecker may peck wood over 50 million times at a force of about 1,200 to 1,400 Gs — more force than a human could remain conscious under.

Previous research had shown their skulls could undergo this sort of trauma without much damage.

But what about their brains?

In a recent study published in PLOS ONE, researchers looked at the buildup of the tau protein in woodpeckers, which normally signifies brain damage in humans.

“We went into it thinking we wouldn’t see anything,” said lead author George Farah, a neurobiologist from the Boston University School of Medicine. “The takeaway was, we could say that woodpeckers have potential to have brain injury.”

Looking at museum specimens, the team compared the brains of red-winged blackbirds (Agelaius phoeniceus), which don’t peck, to those of downy woodpeckers (Picoides pubescens), testing particularly for phosphorylated tau. Two out of the three brains that made it through the testing stages showed large buildups of the protein.

Tau protein wraps around neurons and gives them flexibility while keeping them stable, Farah said. But accumulations of tau occur in the brain when there’s trauma or neurodegenerative disease. The protein becomes unattached from the neurons and the brain has no way of getting rid of it.

“Potential tau deposits aren’t necessarily a bad thing,” Farah said. “It’s possible the phosphorylated tau is adding more of a cushion for these neurons — that instead of wrapping them in duct tape, they’re wrapping them in bubble wrap.”

But it does indicate at least a possibility that the woodpeckers are experiencing some sort of brain damage, Farah said. “We are not coming out swinging, saying these guys have brain injuries,” he said, because researchers would have to study large numbers of the birds to be certain.

Woodpeckers may also have an enzyme for getting rid of phosphorylated tau, Farah said, but that also would need to be investigated further.

“For now, we’re leaving the possibility open and we’re not going to assume woodpeckers don’t have any injury whatsoever,” he said. “It’s possible they do and the skull isn’t doing as much protection as we previously thought, and we need more time and science to say that.”