Riding the leviathan: how the blue whales noms

I‘ve posted videos before on the “barrel roll” of  blue whales feeding on krill and on preliminary data collected by the workers mentioned below; but now there’s finally a published paper and stunning new video that documents how the world’s largest animal feeds on some of the world’s smallest (krill are tiny shrimplike crustaceans). Let me reprise the behavior first; it’s shown at the first part of this not-so-good video. The whale rolls over, opens its mouth, and engulfs a patch of krill.

Jeremy Goldbogen, a graduate student at the University of British Columbia, works on feeding in blue whales.  In the video below, and the paper referenced below, he and his colleagues attached cameras to the backs of blue whales (Balaenoptera musculus, supposedly the largest creature that ever lived at 200 tons—the weight equivalent of about 150 Volkswagen Beetles), and followed their feeding behavior. The video, presented on National Public Radio’s Science Friday, is stunning:

In the paper, published in Biology Letters (free download here), Goldbogen and colleagues describe how (with the help of simulations), the 360° barrel rolls that the whales do when nomming serve two purposes: to orient the whales so they can get a good look at the prey patch from all angles (their eyes are, of course, on the side), and to enable them “to engulf the densest portion of the prey patch.” I’m not sure how the inversion does this, but the video at top suggests that the upside-down position enables them to “scoop up” the water more effectively.

According to Goldbogen et al., a single judiciously executed barrel roll by a dense patch of krill can provide the whale with enough food for an entire day!

The authors also mention three other cases of animals doing rolling maneuvers. I was familiar with the “death” roll of the alligator, in which the reptile spins around and around in the water with prey in its mouth, probably breaking its neck, ripping off a limb, or battering it to death.

Here’s a video of a crocodile doing the death roll, automatically, after it grabs a trainer’s arm [WARNING: don't watch if you don't want to see a human get bitten and his arm mangled]. I’m using the video because it shows the behavior so clearly, and how automatic it is.

The two other cases quoted by Goldbogen et al. involve “remora removal in spinner dolphins and “air-righting in geckos.”  Here’s “air-righting” in geckos, but how could they forget that cats do it, too!?

The video below shows the dolphins spinning as they jump out of the water; one appears to go around three or four times! I’m not sure whether this is for removing the annoying remoras, but it’s new to me:

h/t: Kurt

____________

Goldbogen, J. A., Calambokidis, J., Friedlaender, A. S., Francis, J., DeRuiter, S. L., Stimpert, A. K., Falcone, E., Southall, B. L. 2013. Underwater acrobatics by the world’s largest predator: 360° rolling maneuvers by lunge feeding blue whales. Biology Letters 9, published online: doi: 10.1098/rsbl.2012.0986.

11 Comments

  1. nurnord
    Posted December 9, 2012 at 8:04 am | Permalink

    “[WARNING: don't watch if you don't want to see a human get bitten]. I’m using the video because it shows the behavior so clearly, and how automatic it is. My guess is, based on the post-attack interview, that the trainer wasn’t hurt too badly:”

    Jerry…
    This video has been on YT for a few years and I have studied it previously, and again just now. The man’s arm gets bent (read;snapped !) back 90 degrees and mangled. Pausing at 1:35 clearly shows this !

    Now I it does not bother me, but your warning should indicate what is actually onscreen !

    • whyevolutionistrue
      Posted December 9, 2012 at 8:07 am | Permalink

      Yeah, you’re right; I think I was almost covering my eyes at the crucial moment. I fixed the description, thanks!

      • nurnord
        Posted December 9, 2012 at 8:15 am | Permalink

        No probs, lighting response too ! Take care…
        P.S. I hope RD comments on the Freeman Dyson post, should be interesting !

        • nurnord
          Posted December 9, 2012 at 8:18 am | Permalink

          ‘lightning’ geez…

        • suwise3
          Posted December 9, 2012 at 4:37 pm | Permalink

          After annoying croc by repeatedly bopping him on the head, I would think the croc would be ready to respond a little quicker than usual…

  2. Posted December 9, 2012 at 9:20 am | Permalink

    The spinning dolphins are the Naia, the little spinning dolphins of Hawaiian waters, unique to Hawaii. It is my theory that they spin for joy when “breaching” to breathe.)They were known to native Hawaiians, and “discovered” by Tap & Karen Pryor & friends, who founded Sea Life Park (for revenue) & The Oceanic Institute AKA the Makai Range (for research). Cetologists had denied that there were any distinct species of cetaceans in the Pacific. They were wrong. The Pryors listened to the Hawaiians and identified several: among them the Naia and the Rough Toothed Dolphins (the smartest of all dolphin species, and given to playing tricks, like opening all the doors of their night time tanks & releasing all the cetaceaions into the large pond, resulting in some cross breeding!). When they had to sell Sea life Park to the Fred Harvey company, one of the conditions of sale was that the Naia they held at Sea Life Park would be released back into the wild, because the Pryors were concerned that they were too fragile for the non-scientists who bought the Park to care for properly. You miss a lot by being so unfamiliar with Hawaii — these marvelous dolphins, and the several species of carnivorous caterpillars the first discovered in the world — on the Big Island. That discovery caused a sensation among caterpillar specialists who flew in from all over the world to see it and to congratulate the grad student who had discovered it and documented its life cycle for his Ph.D. dissertation.

  3. Notagod
    Posted December 9, 2012 at 9:36 am | Permalink

    Answer: So christians would never be able to get their right side up.

    Question: Why did most or all of the christian gods cut off all of the christian’s tails?

  4. Michael Fisher
    Posted December 9, 2012 at 12:54 pm | Permalink

    Aeronautically speaking I would say the whales are performing a roll rather than a barrel roll since there is little [or no] helical component to the path.

    I think the visual world of these huge whales must be split into two distinct fields by the massive head & rolling is the most energy efficient way of forming a 3D “picture” of the target krill that doesn’t involve changing the direction of motion. I would suppose that swaying the head from side to side to give each eye a snapshot is another way of triangulating the target, if the creature has the anatomy to do this, but that would be a very energy expensive manoeuvre, would change the whales path & would also increase drag. [I know nothing about whale necks : ]

    Without rolling the whale would have little indication of target distance & she would have to open her jaws sooner to be sure of catching the prime concentration of krill.

  5. abrotherhoodofman
    Posted December 9, 2012 at 1:55 pm | Permalink

    Shrimp cocktail sauce, anyone?

  6. Eohippus
    Posted December 9, 2012 at 4:18 pm | Permalink

    Here’s a video of catfish beaching themselves to nom pigeons;

  7. marksolock
    Posted December 13, 2012 at 9:24 pm | Permalink

    Reblogged this on Mark Solock Blog.


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