Research has discovered why woodpeckers don’t get their beaks stuck in the tree that they are pecking when digging around for grubs or making a nest. They twist their heads once the beak has hit the tree and this separates the upper part of the beak from the lower part which expands the whole which in turn allows the beak to be removed. Of course, it all happens in a fraction of a second. But the action is a bit like that of a drill.
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Shortly after the beak gets stuck, only the tip of the upper beak slides back while the lower beak stays in place. It has to do with the upper and lower beak pivoting about different joints with the cranium, so if you push them both nose-down, the upper beak will slide back with respect to the lower beak, or vice versa. – Prof Van Wassenbergh
The whole process takes place in about 50 ms and is understandably invisible to the naked eye. They were filmed in slow motion at about 7 m a second. It appears that the key to it is that the upper part of the beak moves independently of the bottom half which allows the cavity to be widened. This separation of the beak occurs because the woodpecker’s head rotates slightly as it hits the wood.
Comment: my initial thought was that the research is misplaced. When a woodpecker chips away at wood it is not like a nail being hammered into wood. Nails obviously become fixed but a woodpecker’s beak does not enter into the wood deeply enough for it to become fixed. It simply chips away at it a bit like a chisel removes bits of wood. Therefore I don’t see the prospect of their beak becoming stuck. I just don’t see it myself but perhaps on occasions it does because of the bark presenting grooves and indentations which perhaps might capture the beak. I think it’s more about that than the beak being stuck under normal use.
The research was carried out at Antwerp University. The lead author is Sam Van Wassenbergh. Woodpeckers aren’t the only birds who were able to move their upper and lower beak independently but the research surprised the scientists. They had thought that the beak would be a more rigid structure because of the requirements of hammering. I’ve always thought that a woodpecker is prone to brain damage because of their incessant hammering! I wonder whether research has taken place on that?
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