Everything We Know About Woodpeckers and Shock Absorption Is Wrong

Young Green Woodpecker

Dear Readers, I was taking a walk in St Pancras and Islington Cemetery with my friend A on Monday when we spotted this juvenile green woodpecker, sitting very happily on top of a gravestone. What handsome birds they are, although this one doesn’t have the red cap of an adult. You can clearly see the stiff tail feathers that help the bird to stay upright when working their way up a tree trunk, although the favoured food of green woodpeckers is ants, lots of them.

As we watched, we noticed that the woodpecker and their parent seemed to be being followed by several nosy magpies. The adult woodpecker flew down and started hammering relentlessly into an area of raised, dry ground next to one of the graves, which probably held an ants’ nest. After a few minutes the magpie seemed to approach aggressively and the woodpecker flew off, leaving the magpie to appear to hoover up whatever the woodpecker had unearthed.

I am not in the least surprised that the magpie was intelligent enough to benefit from another bird’s hard work – the crow family has a history of this, with ravens in the Northern Woods of Scandinavia leading wolves and bears to carcasses that they can’t open up themselves. This was the first time I’d seen magpies and woodpeckers interacting though, so do let me know if you’ve ever seen anything similar. I suspect that the web of life is far more intricate and nuanced than we can ever imagine.

Now, how about that headline? For years I have been promulgating the long-held belief that the reason that woodpeckers don’t give themselves concussion with all that hammering is because they have shock absorbers in their heads. Much like the little unicorn horn on the back of Dürer’s rhinoceros (which doesn’t exist, but was replicated by everyone who ever painted or drew a rhino for years afterwards) we have all been blithely repeating the woodpecker story.

The Rhinoceros by Albrecht Durer (Public Domain)

It is true that woodpeckers have spongy bone between their beaks and their brains, but instead of absorbing the shock from the blows, scientist Sam van Wassenburgh at the University of Antwerp has found that that the spongy bone is only there to reduce weight, essential for a flying animal. Videos of three species of woodpecker hammering on wood showed that the spongy bone didn’t have any effect on cushioning the blows – slowing down the video showed that the birds’ heads and eyes stopped moving at the same time as their beaks did. Van Wassenburgh concluded that the bird’s brains are so small and light, and so cushioned by the naturally-occurring fluid in their skulls, that they would have to hammer twice as fast, or hit surfaces four times as hard, in order to suffer concussion.

And so, another idea bites the dust, but this is what science is all about – a scientific theory is the best model that we currently have for why something happens, until someone does the research and it’s replaced by a theory that fits what happens better. I love that we are always learning, and always moving the consensus on. I think two years of studying science has made me more eager to look for evidence, and to not take things at face value, especially in a time of so much deliberate misinformation. We live in exciting times, but we have to be careful about where we get our information from.

You can read the whole woodpecker article, and watch the woodpeckers getting stuck in with their hammering, here.

5 thoughts on “Everything We Know About Woodpeckers and Shock Absorption Is Wrong

  1. Anne

    What a fine view you had of the interaction between the woodpecker and the magpie. I am glad you were able to photograph it.

  2. jay53

    That last sentence has never been truer than it is today. Incidentally, my interest is in Diptera, particularly hoverflies, and it’s amazing how knowledge has increased just in the few years I’ve been recording them. Suddenly a species which I thought I knew has been split into two – or even three – separate species – and with DNA barcoding we can expect much more of that.

    1. Bug Woman Post author

      Hi Jay53, flies are such fascinating animals, and we owe them so much, but everyone seems to think of them solely as pests. DNA analysis is really turning many of our received wisdoms on their heads, for sure. It will be interesting to see what the tree of life looks like when everything ‘settles’ (if it ever does).

  3. Antony

    Hi. Sorry for an off-topic post, but I wanted to share some news about my mum Fran Freelove. She was a frequent commenter in particular for your quizzes. She posted as Fran and Bobby, her sister, but to be honest it was Fran who was actually doing the quizzes!

    I’m very sad to say that she died this morning after a six year battle with ovarian cancer, so you won’t see her regular contributions anymore.

    I cannot explain how much joy this blog brought her. She was of course a keen gardener and bird lover so always had a keen interest in your blog. If she wasn’t doing the quizzes, she was always talking to me (as I live in London) to ask if I’d been to whatever spot Bug Woman was at that week. It was a constant point of discussion between us, even if I am rather less green fingered.

    I am devastated at her loss but wanted to thank you for the joy you gave her through some rough times. And Bobby will continue to read, but admits she wouldn’t have a clue how to comment!

    I am pleased to say that in my last visit with my mum I was able to tell her she got full marks in her last quiz, which give her one last extra smile.

    Thank you again, Bug Woman.

    1. Bug Woman Post author

      Dear Antony, I am so sorry about your Mum – I knew that she had cancer, and I always felt so fond of her, even though we never met. Thank you so much for letting me know what’s happened to her, and I’m sure all of us on the blog here will miss her, especially her spectacular ability with the quizzes! She will always be the champion for all of us here, I’m sure. I will message you privately to find out the details of the funeral as I’d love to send some flowers or whatever she would have wanted.

      I lost my mum in 2018, so I know how devastating this can be, and I’m holding you and Bobby and the rest of the family in my heart xxx


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