Why Don't Woodpeckers Get Brain Damage? Research Presents Exciting New Hypotheses

Forced to spend their days slamming their tiny skulls into the sides of trees in search of buried pieces, woodpeckers should have developed a trick or two to avoid brain damage. So you would think.

A new study of woodpecker biomechanics has cast doubt on speculation that the chisel-headed little bird avoided turning its brains to mush through a fancy shock-absorbing adaptation.

On the other hand, his brain may be too small to care.

“By analyzing high-speed video of three woodpecker species, we found that woodpeckers do not absorb the shock of impact with trees,” said Sam Van Wassenbergh, a biomechanics researcher from the University of Antwerp in Belgium.

Anyone who’s ever seen, or even just heard of, machine gun fire from the woodpecker’s signature beat will appreciate the physics involved.

Snapping their heads back and forth at an astonishing 20 times per second, members of some species can experience forces of up to 1400 g. Compare that to the paltry 90 to 100 grams that can cause a human concussion, and it’s easy to imagine the kind of trauma that might have occurred inside that tiny skull.

Previous research has shown various body modifications that can help reduce the impact on woodpecker brain tissue, such as spongy bone, shock absorbers and neck muscles.

While these features appear to be designed to absorb blows, proving that they manage to reduce force as the woodpecker’s head accelerates and decelerates rapidly is a challenge.

There’s also the question of whether woodpeckers bothered with the safety features in the first place. Their small brains and narrow skulls leave little room for chatter.

In this study, using more than a hundred high-speed videos of six species-represented woodpeckers Dryocopus martius, Dryocopus pileatusand Dendrocopos majorVan Wassenbergh and his team carefully measured the deceleration of their eyes as their beaks met the wood.

Given that the eyeball is a fairly suitable proxy for the slippery interior, the researchers were able to calculate the physics of the slowed skull.

It turns out that the whole head moves as one, with little variation in peak deceleration between the eyes and the beak.

“Their heads basically function as hammers that are stiff and sturdy when pecking,” says Van Wassenbergh.

The biomechanical model built on data gathered from a frame-by-frame analysis of their video only further verified that there was not much shock-absorption between the tip of the beak and the contents of the skull.

All those special bone structures, in this case, weren’t too deformed and absorbed the energy from each blow but also resisted breaking.

This makes the bird’s work more impactful and efficient. “If the beak absorbs a lot of the impact, the poor bird will have to hit even harder,” explained the researchers.

While according to one study, birds may suffer the effects of head-on collisions for a lifetime, the simulations carried out by Van Wassenbergh and his team on the intracranial pressure of the woodpecker’s skull showed that such constant pushing and shoving of the cerebellum meant nothing. for something serious, anyway.

Woodpeckers don’t have to bother with all those safety features.

“The absence of shock absorption does not mean their brain is in danger during a seemingly violent impact,” Van Wassenbergh said.

“Even the strongest shock of the more than 100 blows analyzed should still be safe for the woodpecker brain because our calculations show a lower brain load than humans suffering from concussions.”

This finding helps explain why woodpeckers never evolved to be much larger than about half a meter (about 22 inches) in length. While muscular hairy jackhammers could drill through larger pieces of food, their heavier brains wouldn’t be able to withstand the pressure.

That is, although their brains are small, woodpeckers are not that stupid.

This research was published in Current Biology.

#Dont #Woodpeckers #Brain #Damage #Research #Presents #Exciting #Hypotheses