A remarkable new study claims that woodpeckers may actually suffer some grave consequences from slamming their heads into trees. While woodpeckers’ bodies are built to withstand the blunt force trauma of hammering their bills into trees to make homes for themselves, which they have done for millions of years, scientists examined their brains and came to some fascinating conclusions.

They found that there were build-ups of tau, a protein, in the brains of woodpeckers, and this same protein when found in humans is indicative of both head trauma and neurodegenerative diseases. They examined Downey Woodpeckers and Red-winged Blackbirds, which is not a pecking bird, and compared the two species to find that woodpeckers had a significant tau build-up while the black birds did not.

Scientists are not sure if this is actually a sign that there is brain damage, or a protective measure by the body to prevent damage to the brain. The woodpecker already has adaptations that help protect it, like the special design of its skull and its beak.

“There have been all kinds of safety and technological advances in sports equipment based on the anatomic adaptations and biophysics of the woodpecker assuming they don’t get brain injury from pecking. The weird thing is, nobody’s ever looked at a woodpecker brain to see if there is any damage,” says Peter Cummings of the Boston University School of Medicine, one of the new study’s authors, according to a Field Museum statement.