I'm afraid his knowledge of the woodpecker's head is sadly lacking, the cartilage he mentions is of necessity only a very minor part of it's brain protection.
In fact it's brain is smaller than the skull chamber it sits in and it's surrounded with fluid having a viscosity matched to it's rapid beak strike rate when drilling. The result is that it's brain remains almost motionless as the beak and skull rapidly beat on the timber, the fluid doing the shifting while the brain mass inertia holds it almost stationary in space.
That said, I hope his work results in better helmets than those we have at present, polystyrene lacking in many respects.