Woodpeckers' heads act more like stiff hammers than safety helmets

How woodpeckers can continuously strike tree trunks with their beaks without harming their brains has long been a mystery to scientists. Because of this, it was assumed that their skulls must function as shock-absorbing helmets. Researchers have already debunked this idea, claiming that their heads behave more like stiff hammers and published their findings in the journal Current Biology on July 14. Their calculations really reveal that any stress absorption would interfere with the woodpeckers' ability to peck.

Sam Van Wassenbergh from the Universiteit Antwerpen in Belgium states, "We discovered that woodpeckers do not absorb the shock of the hit with the tree by studying high-speed footage of three species of woodpeckers.

First, Van Wassenbergh and associates calculated the effects of pecking decelerations in three different woodpecker species. They built biomechanical models using the data and came to the conclusion that any stress absorption in the skull would be harmful to the birds.

Do their brains suffer damage from the ferocious pecking if their skulls don't serve as shock absorbers? In actuality, it doesn't. The deceleration stress associated with each peck surpasses the accepted threshold for concussion in humans and primates, yet the smaller brains of woodpeckers can sustain it. According to Van Wassenbergh, woodpeckers are capable of making mistakes, such as when they peck metal with all of their might. But even without the protection of their skulls functioning as protective helmets, their normal pecking on tree trunks is often considerably below the threshold to produce a concussion.

According to Van Wassenbergh, "the absence of shock absorption does not mean their brains are in danger during the obviously intense blows." "Our estimates indicated brain loadings that are lower than those of people experiencing a concussion," the researchers said. "Even the biggest shocks from the over 100 pecks that were evaluated should still be safe for the woodpeckers' brains."

According to Van Wassenbergh, the results disprove the long-held hypothesis of shock absorption, which has gained popularity in the media, literature, zoos, and other places. He claims that when documenting woodpeckers in zoos, he overheard parents telling their children that woodpeckers don't get headaches because their heads have shock absorbers built in. Our findings now dispel the misconception that woodpeckers absorb trauma.

He claims that the data may provide an evolutionary explanation for why there aren't woodpeckers with significantly bigger heads and neck muscles. Although a bigger woodpecker could be able to produce more forceful pecks, concussions would probably cause them serious issues.

Considering that engineers have previously drawn inspiration from the structure of the woodpecker's skull bones for the creation of shock-absorbing materials and helmets, the discoveries also have some practical implications, he continues. The latest research indicates it's not a smart idea, given that the structure of woodpeckers reduces stress absorption.

Van Wassenbergh points out that a recent research by his team revealed that woodpeckers frequently get their beaks caught, but the birds are able to swiftly extricate themselves by alternately moving their top and lower beaks. How the beak shape is modified for pecking is currently being researched.

Grants from the University of Antwerp, the Agence Nationale de la Recherche, and the Horizon 2020 initiative of the European Union all helped to fund this study.

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