The Dorsal Fin – Shark News

Visual abstract: white sharks scavenging on whales in False Bay

by on Apr.11, 2013 at 4:05 pm, under Shark Videos

The R.J. Dunlap Marine Conservation recently posted the video above to their Vimeo channel. The video is intended as a supplemental “visual abstract” for the research article “White Sharks (Carcharodon carcharias) Scavenging on Whales and Its Potential Role in Further Shaping the Ecology of an Apex Predator.” The study is based on observations of great white sharks feeding on the carcasses of whales in South Africa’s False Bay and the impact of these events on the surrounding marine ecosystems.

Some key behavioral observations during scavenging at the sites of the whale carcasses:

  • a tendency for the white sharks to feed on the fluke first, followed by blubber-rich content
  • an absence of eye rolling (to protect the eye) during feeding on the carcass
  • a broader variance in individual white shark sizes than is typically seen in the area
  • a lack of competitive aggression between white sharks
  • a size-dominance based hierarchy (aka “pecking order”)

You can learn more about the findings of this research by checking out the full journal article, which was written by Chris Fallows, Austin J. Gallagher, and Neil Hammerschlag.

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4 Comments for this entry

  • drudown

    Let me get this straight.

    The researchers seem to concede that White sharks have the “strong idea of how to interpret and consume the carcass”…but the researchers still cling to the fiction that White sharks can’t tell the difference between seafaring primates and fat rich pinnipeds? That is how ridiculous “mistaken identity” theory is. Namely, despite mounting evidence that White sharks are more intelligence than previously thought, the rigid “mistaken identity” dogma remains.

    As an aside, the fact the White sharks’ nictitating membrane is not triggered likewise underscores how absurd “mistaken identity” is. By analogy, it underscores the selfsame reason why White sharks do NOT typically employ high-energy ambush attacks in instances of human predation. As here, the White shark is fully cognizant of what it is eating. Humans cannot escape (see, e.g., “shark takes woman’s leg” on youtube).

    Finally, I’ve seen Tiger sharks go for the fluke first. Given that the Tiger shark behavior was seen on a dying whale, my theory is that it is “standard protocol” for large, pelagic sharks to start here as a basic means of immobilizing the whale (i.e., limit its primary means of locomotion). The fact they are seen doing it on deceased whales tends to show it is a deeply ingrained behavioral trait. After all, the importance of ensuring the feeding event outweighs the risk that it is ‘somewhat’ wasted energy compared to higher calorie bites.

    As for the researchers regurgitation theory…uh, given that the White sharks are gorging themselves in a highly competitive environment…perhaps the regurgitation is analogous to when a large constrictor regurgitates large prey when confronted by a threat, i.e., between ensuring self-preservation and mere caloric intake- particularly, as here, in such abundance…the choice is involuntary made via instinct.

    Food for (ahem) thought

  • TheDorsalFin

    Just a note, white sharks do not have a nictitating membrane.

  • drudown

    Thanks; but my point is the same: if their eyes do not roll back (i.e., serving the same evolutionary function as a nictitating membrane in other pelagic sharks) this nonetheless helps establish their cognitive prey differentiation patterns that touch and concerns relative risk of injury, no?

  • drudown

    Second thing.

    Isn’t it true that during the entire history of whaling…White sharks and mankind obviously, had an unbroken, symbiotic course of dealing. Given the self-evident importance of blubber in White shark diets, this should be carefully considered.

    I’ve always thought that’s what White sharks are doing out at “White shark cafes”….waiting for scent of dead whales where they (1) gorge themselves and (2) look for mates under such amicable conditions.

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