Starts With A Bang!

Q & A: Why don’t Woodpeckers get Brain Damage?

Everyone knows how much fun it is to get repeatedly hit in the head. Just ask Oscar de la Hoya after his defeat against Manny Pacquiao last weekend:

Ouch. It isn’t just boxers, either. Every animal that experiences head trauma is susceptible to the following symptoms:

• Abnormal level of consciousness
• Differences in pupil size
• Rigid limbs
• Flaccid limbs
• Unusual eye movement
• Bleeding from the nostril
• Bleeding from the ear canal
• Seizures
• Head tilt

But the worst thing imaginable to me that results from head trauma is brain damage. It’s our minds that make us who we are, and the idea of living without mine is completely horrifying. Look at how different a normal brain can be from a damaged one:

Out of all the animals I know of, there’s only one that repeatedly slams its head into a block of wood, over and over, day in and day out, for its entire life: the woodpecker.

A woodpecker moves so quickly that its tiny, 50 gram head absorbs 1,300 pounds of force every time it smashes into a tree! So why don’t woodpeckers get brain damage? There has to be something that prevents its brain from rattling around in its head and slamming against the skull around it, right? No, there isn’t. The woodpecker’s brain does rattle around in its head and smash into its skull. Yet it still emerges brain-damage-free. There are three special adaptations of a woodpecker that allow this to happen; let’s take a look.

1. Spongy skull bones — while humans have spongy bones mostly on the interior of large bones, woodpeckers’ skulls are extremely spongy. This means they can compress and help absorb the impact of the brain jostling around. It’s like smashing a brain into memory foam instead of into solid bone, and it reduces the force on the brain tremendously.

2. Large surface area — a woodpecker’s brain is tiny. This is actually a positive thing, because the smaller something is, the larger its surface-area-to-volume and surface-area-to-weight ratios are. If something has a bigger surface area, it means that even if the force is large, the pressure gets smaller, and this helps protect the woodpecker’s tiny bird-brain.

3. Woodpeckers peck in a straight line — this one is hugely important. If everything’s in a straight line then there’s no rotating or torquing of the brain, and therefore no tearing of the nerves in the brain. Hence, no brain damage the way that car crash victims experience it.

And those three things combined allow a woodpecker to escape from all their daily pecking activities without so much as a hint of head trauma. Isn’t evolution neat?

What, you were expecting some astronomy/physics today? Go check out the latest Carnival of Space to get your fix, done by Dave Mosher in a new video format, and I’ll see you all next time!