Forced to spend their days slamming their tiny skulls into the sides of trees in order to find food, woodpeckers should have evolved a trick or two to avoid brain damage. You would think that's true.
The study casts doubt on the idea that the small chisel-headed bird avoids turning its brain to mush through fancy shock absorbers.
It may be too small for it to care.
Sam Van Wassenbergh is a researcher from the University of Antwerp in Belgium.
The physics involved in the machine-gun fire of a woodpecker's signature tapping would be appreciated by anyone who has seen it.
Members of some species can experience forces of up to 1400 g when they snap their heads back and forth. It's easy to imagine the kind of trauma that might occur inside that tiny skull if you compare that with the measly 90 to 100 g that can give a human concussion.
The impact on the woodpecker's brain tissue can be lessened with a variety of body modifications.
While these features seem to be designed to absorb a blow, proving that they can reduce the forces as the woodpecker's head decelerates is a challenge.
The question is whether the safety features bother the woodpeckers at all. Small brains and tight skulls make them hard to rattle.
Van Wassenbergh and his team carefully measured the deceleration of their eyes as they watched more than a hundred high-speed videos of six woodpeckers.
The eyeball is a good proxy for the squishy insides.
The whole head moves in a straight line, with little variation between the eye and beak.
According to Van Wassenbergh, their heads function like solid hammers.
There wasn't a lot of shock absorption between the tip of the beak and the skull, thanks to biomechanical models constructed on data collected from a frame-by- frame analysis of their videos.
The specialized bone structures don't do much to absorb energy from blows as much as resist fracturing.
The birds' work is more effective. The unfortunate bird would have to pound harder if the beak absorbed a lot of its own impact.
According to one study the birds may suffer the effects of a lifetime of head-banging, but simulations done by Van Wassenbergh and his team suggest the constant pushing and shoving on such small brains doesn't mean anything.
All those safety features are not needed by the peckers.
According to Van Wassenbergh, the absence of shock absorption doesn't mean the brain is in danger.
Even the strongest shocks from the over 100 pecks that were analyzed should still be safe, as our calculations showed brain loadings that are lower than that of humans suffering a concussion.
The findings show that woodpeckers never evolved to be much larger than half a meter. The heavier brains of jackhammers wouldn't be able to handle the pressure.
Although they have small brains, the woodpeckers are not so stupid.
The research was published in a journal.
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