This is an update to my earlier post Funny Bones about the interactive museum exhibit piece I’m working on for the Carnegie Museum of Natural History. I recommend reading that post for context first if you haven’t.

Update

Spent some time tonight building out an idea I’d had of how the red-bellied woodpecker’s wonderfully elongated hyoid bone could be made into an interesting physical model. It’s a bit frictiony at the moment, but for a first pass, I was able to go from drawing to realization and so far, I’m happy with the outcome.

I’m a woodpecker! Sort of.


A biological review

The red-bellied woodpecker (Melanerpes carolinus) has a very long hyoid bone that it uses for a few purposes, including allowing its tongue to extend very far out of its beak so it can get at the insects hiding inside trees. As a reminder from the previous post, here’s what the skull of the bird looks like:

melanerpesSideCrop author’s image of Carnegie Museum of Natural History specimen, catalog #S16454

The hyoid bone extends from the top front of the cranium around the back, then underneath, then into the beak, then finally out to the base of the barbed tongue. That’s the thing I’m trying to make.

Building the bird

I started the night making a little drawing of what I was thinking of building: a bird beak model, built onto an old bike helmet, that would let the user physically push on a lever to advance the hyoid bone, and in so doing poke out a barbed tongue.


And then I got to work. In my model, the bone itself is some heavy-gauge stranded copper wire, which gets threaded into a length semirigid plastic tube, acting as the muscle sheath the bone rides inside of. (I was fortunate enough to have ready access to heavy wire and plastic tubing of the right size!)


I roughly measured out the amount of tubing that would be needed to run the whole length of the hyoid and then glued part of it onto the helmet.


Cutting a slit along part of the tubing that was glued to the helmet, I made it possible for the wire to slide along the tubing while still being accessed from the side.


I found some thin pieces of carbon rod (again, a very lucky find—had been planning to make this part of out of metal rods but the carbon is great) and hot glued these to the helmet so they’d meet at a point maybe 10” in front of the user’s forehead.


I whittled a tongue-tip with barbs out of a dowel and used zip ties to attach it to the end of the hyoid.


Ended up with a reasonable functioning model that I’m happy with as a first pass. Surprisingly, my plan wasn’t so different from what I actually ended up making. Strange! But sometimes it happens that way.