Head-Banging Woodpeckers Could Give Themselves a Concussion Every Day: Here’s How They Avoid It

Birds spend all day hammering their heads on tree trunks, using their beaks to make holes and dig insects out of those holes for a meal. Researchers theorize that the bone between the beak and braincase of the birds protects their brain from concussions. According to a new study, their head and beak act like a stiff hammer for optimal performance.

The bird has to dig holes in the wood all day long. Sam Van Wassenbergh is an evolutionary biocist who leads the new study. If the woodpecker absorbs some of the energy it directs at the tree, it will be harder to make holes in the tree trunk. The more you think about it, the less it makes sense. The test had to be done.

Researchers used high-speed video of three species of woodpeckers to investigate the question. As the birds hammered the trees, they tracked the motion of different parts of the woodpeckers head to see if there was any cushion. The team did not find what they were looking for. The head was a stiff hammer with little to no resonance. The results were reported in a journal.

This is the first time that high-speed video has been used to determine how much force is being loaded onto the bill of a woodpecker.

How do woodpeckers not get hit in the head? The researchers used simulations to calculate the impact on the brains of the birds, and compared it with thresholds for concussion-causing forces in humans. A concussion can be caused by an impact of 135 g's. The woodpeckers are small. According to Van Wassenbergh, their brain is about one seventh the length of a human's. The force that the brain sustains is below the danger threshold. He says that if they hit the tree at higher speeds they wouldn't suffer a concussion. The head of the bird is smaller than that of a human.

The brain injury chronic traumatic encephalopathy is most often found in offensive linemen who receive repeated shocks. woodpeckers may have some mechanisms that protect their brain from the effects of subconcussive events. Steroids may have protective effects on the birds brain, according to the work of Tobiansky and his colleagues.

It is not known how brain protection works. The design of helmets for humans isn't likely to be inspired by the woodpecker braincase. A crustacean, a member of a class of animals that specialize in hardened exteriors, might provide better insight on how to proceed.

The snapping claw is a weapon the territorial animal uses to battle invaders and defend its home. The claw has a mechanism that shoots the plunger through the hole at high speeds. A bubble of air is created when a jet of water shoots out, creating an area of low pressure. There is a snapping sound and a brief burst of light. There is a high-amplitude pressure wave that can cause damage to soft tissues such as the brain.

Two shrimp try to intimidate their opponent in a game of chicken by snapping within a millimeter of each other. Brain damage can be caused by the waves from the snaps.

The snapping shrimps have a secret to cope with the onslaught. They have a transparent, gogglelike structure called an "orbital hood" which protects their brain from the pressure waves. On July 5, the researchers reported their findings.

There has been a lot of research on the evolution of weapons and how to defend against them, but not much on how to defend against them. The question is particularly interesting because the weapon can be harmful to the shrimp and its opponent. She says that you need protection from others but also from your own use of the weapon.

Researchers removed the orbital hoods from some of the snapping shrimp to understand how they cope with shocks. The team exposed the hoodless shrimp to shock waves from other shrimp and found that they became confused and lost control of their limbs. The animals exposed to shock waves did not have any problems.

The researchers used small sensors to measure the pressure inside and out of the orbital hoods as the shrimp were exposed to a snap. The magnitude of the shocks was cut in half by the orbital hoods. "When we have an animal that has their helmet on, it's pretty effective at dampening those shock waves, so we get less energy reaching the brain underneath the hood." The shock waves reach the brain at full strength when the hood is taken off.

What is the effectiveness of the goggles at protecting the animal's brain? Kingston and her colleagues theorize that a shock wave will force water out of the orbital hood and away from the animal.

They put goggles on some snapping shrimp to see if it would work. The team found that when the shrimp were exposed to a shock wave, they hit the brain as if they weren't there. The ability to expel water from the bottom of the hood is important to the brain.

The design of equipment that protects humans from traumatic brain injuries could be inspired by understanding how tiny helmets work. Brain damage can be caused by shock waves from an explosion. Military personnel are more likely to suffer mild traumatic brain injuries. Armored vehicles can't protect against shocks. Dan Speiser is a visual ecologist at the University of South Carolina.

The two animals that seem to risk brain damage all the time are the peckers and snapping Shrimp. New medical or engineering solutions to prevent brain injuries in soldiers and athletes could be inspired by their brain protection tricks.