Shoebills lie tell the truth (and it’s disgusting)

January 27, 2020

Heinrich Mallison sent me this amazing photo, which he found unattributed on Facebook:

Infuriatingly, I’ve not been able to track down an original source for this: searching for the text just finds a bunch of reposts on meme sites, and Google’s reverse image search just reports a bunch of hits on Reddit:

The line-drawing shows some scientific understanding of bird skeletons, so I imagine someone put real thought into this and is unhappy that the image is propagating uncredited. If that person reads this, please leave a comment: I’d love to credit it properly.

Anyway … what’s going on here?

Birds (like all vertebrates) have two tubes running down the ventral aspect of the neck (i.e. below the vertebrae): the trachea, for breathing, and the oesophagus, for swallowing. But these both open into the back of the mouth and are not piped up past it. I’ve not dissected enough bird heads to show this clearly, but when I was taking Veronica apart the trachea was pretty visibly ending in the mouth cavity, not plumbed up past the mouth into the nasal space:

So yes, I think it’s true: shoebills can bulge their spines out of their mouths.

Why? My best guess that there’s just nowhere else for the spine to go when the neck is retracted. There’s a big empty space in the mouth, why let it go to waste?

24 Responses to “Shoebills lie tell the truth (and it’s disgusting)”

  1. nwfonseca Says:

    That illustration looks very much like one from Helen Kairo of (Ars Anitomika) I follow her on facebook. She has lots of interesting anatomical illustrations like this although I couldn’t attribute this one to her. Incidentally, there are images of pelicans doing the same thing. Seems like the bigger the head the easier it is to do. I bet a google search of different bird species with big heads, mouth open would show similar.

  2. Matt Wedel Says:

    It might be more accurate to say that shoebills tell the truth, it’s just a disgusting truth. Although I guess the lie holds as long as they don’t open their mouths–as do most lies.

  3. Mike Taylor Says:

    You’re right: shoebills do lie, but only when their mouths are closed.

  4. David Marjanović Says:

    You can’t handle the truth!!!

  5. David Marjanović Says:

    You can’t handle the truth!!!

    And neither can Akismet, interestingly.

  6. David Marjanović Says:

    You can’t handle the truth!!!

    And neither can Akismet, interestingly. Hmmm. This might need even more filler text. Like… when you’ve got such a long neck, and your lower jaws are nonetheless almost as long, and bulge out far wider than the neck, and your tongue is negligible, it’s not surprising you can put your lower jaws around all of your neck.

  7. David Marjanović Says:

    …Oh. Sorry. Akismet can handle the truth, it just needs a while.

  8. Mike Taylor Says:

    Yep, Akismet was always OK with your truth :-)

    Next question: did T. rex do this?

  9. Haoyang Wang Says:

    Pelican spine through mouth at 0:30

  10. Mike Taylor Says:

    That ain’t right, man.

    Seriously, thanks for finding this. Truly horrible.

    Also, this related video:

  11. Carel Says:

    This looks like the common behavior of pelicans that’s known as “glottal exposure.” Pelicans are thought to be the closest relatives of shoebills (not cranes, of course). The reason pelicans do it is the subject of some speculation and disagreement, so it’s interesting to see that the behavior might well be shared with shoebills.

  12. aquadraco Says:

    The earliest mention I can find of the photo (but not the drawing) is from 2014. The image was taken by a lady who apparently works in a zoo in the Tokyo area, and who is obsessed with shoebills. She has a Twitter page, but her blog is at

  13. Mike Taylor Says:

    Thanks, aquadraco — that certainly looks like a credible source, but I don’t actually see this image (or one like it) on her page. Frustratingly, I can’t see a way to contact her and ask. Can you?

  14. aquadraco Says:

    Sorry Mike, unfortunately I can’t. I found the photo through some reverse image search sites, pasted the blog address into Google Chrome and let the browser translate it. I don’t speak Japanese and Chrome’s translation is a bit clunky so everything’s rather hit and miss. The modified image is also a few years old, and was combined with an anime-style character in some versions. Maybe it was altered by someone on Deviantart?
    Regards, Jim.

  15. aquadraco Says:

    Oops, forgot to mention – I’m not on Twitter or Instagram, but her Twitter address is and her Instagram address is
    If you can get a Japanese speaker to translate for you, you should be able to contact her directly :)

  16. Squiddhartha Says:

    Missed opportunity for a “stinkin’ theropods” tag. :)

  17. Mike Taylor Says:

    Fixed, Thanks, Squiddhartha!

  18. Stephanie Says:

    The photos were caught mid yawn. It took a bit of time, but I found a video with the explanation.

  19. Mike Taylor Says:

    Darren Naish tweets about this, and provides a reference in the formal literature:

    I think the “Schreiber 1977” citation is to:

    Schreiber, R. W. 1977. Maintenance behavior and communication in the brown pelican. American Ornithologists’ Union Ornithological Monographs 22:1–78.

  20. Mike Taylor Says:

    Yes, that is indeed the correct paper. Schreiber discusses this behaviour, which he terms “glottis exposure”, and discusses it (along with a related behviour termed “bill throw”) on pp. 9-14. He says these movements “function in stretching the gular pouch and arranging the esophagus, trachea, connective tissue, and air sac system of the throat and upper breast.” (pp. 9-10).

  21. Sam Lutfi Says:

    It is more an optical illusion in a way. The spine isn’t protruding at all, they are yawning and stretching the lower part of their mouth over their necks. It just appears that something is sticking out but that’s just the base of their bill stretched out over its neck

  22. Mike Taylor Says:

    It’s one of those interesting figure-and-ground problems. Is the neck sticking up through the lower jaw, or is the lower jaw pressed down around the neck? Of course, it amounts to the same thing; but it does affect how we think about it.

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