Woodpeckers have small dura mater between their brains and skulls, so they don’t have concussions like humans. And their brains are bigger up and down than before, which means that the forces acting on the skull are better dispersed.
Scientists have discovered a mature bone called hyoid bone, which exists only above the laryngeal node in humans. The hyoid bone extends from below the beak to the nostril, under and around the skull, and eventually converges over the top of the skull at the forehead.
Zhang Ming, one of the co-authors of the new study, said he and his colleagues wanted to use quantitative analysis to find out the truth. He told the BBC that most previous studies had been limited by qualitative answers and that more quantitative analysis was necessary to answer this interesting question. This study would be of great help to the design of human life protection devices and even some industrial designs.
Researchers set up a specific environment to observe woodpeckers. They used sensors to test the force of pecking and two slow-lens cameras to capture the pictures. The researchers used computed tomography (CT) and scanning electron microscopy (SEM) to collect analysis data of woodpeckers’skulls, detailing how these parts were combined and where bone density changed. With the data collected, scientists can use computer simulations to demonstrate the effects of woodpeckers on skulls during pecking.
Researchers demonstrated through simulation that three factors could reduce the damage of force to woodpeckers. First, the hyoid structure surrounding the whole skull acts as a seat belt in the initial impact. Secondly, the upper and lower parts of the beak are unequal. When the impact force is transmitted from the tip of the beak to the bone, the structure weakens the impact force and keeps it away from the brain. Finally, the “sponge” layered skeleton in different parts of the skull can help to disperse the impact and thus protect the brain.
Researchers emphasized that protecting the woodpecker’s brain from damage is a combination of these three factors, not a single one. This discovery will help scientists design more effective protective devices to protect the human brain.