Late morning, a cup of coffee on my side, getting ready to start working.
Concentration kicks in.
- Tuc-tuc-tuc - What is that?
- Tuc-tuc-tuc-tuc - This is definitely too close.
- Tuc-tuc-tuc - Concentration is lost.
- Tuc-tuc-tuc-tuc - My curiosity drags me to the window.
- Tuc-tuc-tuc - Is it a neighbor? Is it a kid?
I see my answer in the closest tree: A Great Spotted Woodpecker. With such an elegant shape and a great mix of colors, my ears couldn't believe that this small visitor of 22 cm was being so loud. But more importantly, I was mesmerized looking at him, trying to get some delicious food by fiercely smashing his beak against the wood. I couldn't stop thinking how much this must hurt... but it doesn't. How come he doesn't hurt himself doing this? Why his brain is not affected after many times he does this?
As strange as this feeding method might be, woodpeckers have several adaptations that altogether help to reduce the impact on the brain 🧠:
First, their hyoid bone is very modified. In humans this bone is in our neck area, compared to birds where it is a direct support for the tongue. But in woodpeckers evolution went crazy, and this bone is not only extremely long but it's also wrapped along the skull. This offers more support to the whole cranium and works, as Wang's paper cleverly described, "like a safety belt". The skull is not only stronger than other birds but it is also more compressible, like a strong sponge. The lower beak is a strong bone, while the upper beak is covered by a big layer of tissue functioning as a cushioning system. Inside the skull, the brain is not surrounded by lots of liquid like ours, but it's more tightly protected by the bone. This impedes that the brain is dancing inside the skull every time they hit the tree.
But eyes are also a delicate part of every animal. Humans developed safety goggles to protect them during special jobs. Woodpeckers also protect their eyes by closing the nictitanting membrane, a third eyelid which you can see activated in the second picture:
If I need to have a neighbor hammering all day - Tuc-tuc-tuc - I'm happy it's this one.
📑 References and further info:
Wang et al. (2011). "Why Do Woodpeckers Resist Head Impact Injury: A Biomechanical Investigation". PLoS ONE 6(10): e26490.
📸 Pictures: Irina Formoso.
Great Spotted Woodpecker (Dendrocopos major). Munich, Germany. 2019.