Thursday, October 17, 2013

Downy Woodpecker

On Sunday, Erika and I happened upon this Downy Woodpecker defying gravity, while pounding away on a dead tree stump. Apparently the bird is hanging by placing the tips of its claws into small holes in the wood.

Erika wondered why woodpeckers don’t suffer concussions and was sure the National Football League would really like to know. I turned to Erika and asked her to remind me not to get into the woodpecker line at the Reincarnation Center.

We knew that woodpecker neck muscles are relatively thick and help avoid brain injuries. I have previously blogged about woodpecker nictitating membranes, which keep woodpecker eyes from popping out when the bird pecks. A bit of Internet research came up with a 2011 article in Science China: Life Sciences. Compared to Mongolian Sky Larks, Great Spotted Woodpeckers have a thick, spongy skull.  This structure shields the woodpecker’s brain from g-forces 1,000 times that of gravity; humans do poorly when subjected to g-forces as low as 46 times gravity (

Furthermore, woodpecker beaks are also relatively spongy, which may absorb the impact while the bird drills, diverting the shock away from the brain. This adaptation is sort of like indentations in automobile chassis that buffer the cabin from head-on collisions—although the last time I noticed, the car chassis did not retain its original structure after the crash.

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