Woodpeckers don't have shock-absorbing skulls — scientists assumed they did for decades

For years the standard explanation for why woodpeckers never get concussions was a built-in shock-absorption system in the skull. A 2022 study using high-speed video and biomechanical modelling found no such cushioning: woodpecker skulls act as stiff, rigid hammers, and shock absorption would actually waste energy and blunt their pecking. The birds avoid injury instead through small brain size and orientation, keeping forces well below the threshold that would concuss a human brain.

— Sam Van Wassenbergh et al., Woodpeckers minimize cranial absorption of shocks — Current Biology, 2022