Pelican vertebrae are mostly air

July 16, 2014

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I was at the Natural History Museum of Los Angeles County yesterday to do some research in the ornithology collection. After lunch I was working on this pelican skeleton and I thought, “Geez, there is just no way to do this thing justice with still photos. I should make a video.” Here it is. You’ll want to see it full-screen–this being my first time out making a video, I didn’t realize that I was holding the phone the wrong way for efficient viewing on other devices.

The specimen is LACM Ornithology 86262. I’m posting this video with the knowledge and kind permission of the ornithology collection staff.

For previous things in this vein, please see:

If you like it that stuff like this exists, please support your local natural history museum, especially the LACM, which has some really fantastic education and outreach programs.

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11 Responses to “Pelican vertebrae are mostly air”

  1. Mark Robinson Says:

    Thanks Matt, fascinating stuff. If a picture is worth a thousand words, is a video worth a thousand pictures?

    I’ve seen a pelican skeleton (no touching allowed) and I’ve had a quick look at an individual turkey vertebra (dinner, and I was getting looks from the other guests) but it’s always nice to have someone that knows what they’re talking about show you something.

    I’m looking forward to you picking up and videoing OMNH 53062 when you’re next in the area.

  2. engh Says:

    assuming matt’s iphone is shooting video at the standard 29.97 fps his 1 minute 34 second movie is actually worth around 2,817 pictures, or around 2,817,180 words.

    SV-POW Studios Productions ftw.

  3. BenB Says:

    It’s amazing how much the video adds to the ability to truly visualize this. 2,817,180 words sounds about right. Looking forward to you doing the same quick and easy video with BYU 9024.

  4. Allen Hazen Says:

    That’s air ABOVE the neural canal. What about below: is the centrum pneumatized?

  5. Mark Robinson Says:

    @engh – nice math Brian, but I think it’s a mistake to count each video frame as an entire picture. I have no doubt that you’re aware that most of the frames of digital video are far from complete and simply encode the changes from the previous frame.

    The numbers will vary depending on the compression algorithm used, as well as video length, resolution, lighting, etc, but perhaps this particular video is roughly equivalent to one megaword after all?

  6. Matt Wedel Says:

    That’s air ABOVE the neural canal. What about below: is the centrum pneumatized?

    Yes, absolutely. I only focused on the pneumatic spaces in the neural arch because they were easier to see. You can see foramina going into the centrum on the floor of the neural canal–these probably actually communicated with the air spaces inside the centrum. You can also see holes on both of the articular ends of the vertebrae, I suspect that these are only foramina in the osteological sense–in life, the articular ends of the centrum would have been covered with articular cartilage. I think that the diverticula inside the centrum sometimes erode the bone away from the back surface of the cartilage, so that when the cartilage comes away after death, it looks like there was a foramen there, when there was no functional passage in life.

    Pelicans are super-bizarre. Not only do they pneumatize the whole axial skeleton and the proximal limb bones, they also pneumatize most of the distal limb bones as well, out to the manual phalanges. They probably have next to zero hematopoietic bone marrow, because there’s simply no place for it to exist, except maybe in the pedal phalanges (maybe–I haven’t checked). I assume that they make their red blood cells in their spleens.

  7. LeeB Says:

    I wonder if Shoebill Storks also have similar levels of pneumaticity in their bones; or if it is confined to Pelecanus only?
    And Hammerkops might be worth checking out too.

  8. Matt Wedel Says:

    Yes on the shoebill storks. Not quite to the same extreme as pelicans–AFAIK, nothing is quite as extreme as pelicans–but still more pneumatic than most birds. Ditto for most other storks, and herons, albatrosses, frigatebirds, vultures, swans–pretty much all your big flying taxa, especially those that soar.

    I don’t know about Hammerkops, haven’t ever looked at them specifically, but I suspect they are fairly pneumatic.

    Essentially all of the work to date on the patterns of pneumaticity across bird clades and possible causes for those patterns has been done by Pat O’Connor. The most relevant papers are:

    O’Connor, P.M. 2004. Pulmonary pneumaticity in the postcranial skeleton of extant Aves: a case study examining Anseriformes. Journal of Morphology 261:141-161.

    O’Connor, P. M. 2009. Evolution of archosaurian body plans: Skeletal adaptations of an air-sac-based breathing apparatus in birds and other archosaurs. Journal of Experimental Zoology DOI: 10.1002/jez.548

  9. LeeB Says:

    So very large birds have an increased level of pneumaticity but pelecans have a level that surpasses even those.
    I was wondering if the increased level was only in Pelecanus or was in their closest relatives as well; but from what you say at least the shoebill doesn’t have it’s pneumaticity enhanced with respect to other large birds.
    So it is an apomorphy for pelecanus alone.

    Frigatebirds are supposedly incredibly light for their size so no surprise that they have high levels of pneumaticity.

    Do you know if the recent paper on Pelagornis sandersi says anything interesting on it’s (and other bony-toothed birds) pneumaticity?


  10. […] (= air-filled). For a really visceral look at how much air there can be in the bones of birds, see this post, and this one and this one for […]


  11. […] cervical vertebrae is almost inevitable because of their uniquely fragile construction. As in modern birds, the cervical vertebrae were lightened by extensive pneumatisation, so that they were more air than […]


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