Wrangling a Snapping Turtle

We showed this portly specimen when I gave a talk at a local library a while back. Afterward, it momentarily gave its teenaged wranglers the slip and went running. . . straight into the brick wall of the library. Once recaptured, it was returned to the river it came from. 










Photos by Elizabeth Murphy

19 comments:

  1. Snapping and alligator turtles are fascinating beasts.
    I know they are powerful predators, but I wonder if sometimes they fall prey to animals as gators and - in the Everglades - large Burmese Pythons.

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    1. Interesting question, Max. The mortality of adult snapping turtles is typically very low; predation on them must be uncommon. I looked around a little bit and found no evidence that alligators prey on them. The American alligator is known to prey on large turtles, but I have not found either US species of snapping turtles listed among their prey. One survey in Florida, for example, found four species of turtles in alligator stomach contents, but none of them were snapping turtles. However, this is only a one survey in one region.
      My guess is that the turtles’ thick shells protect them from pythons and other constrictors. I have seen their shells crushed under car tires, but never by other animals. The width of an adult specimen would also seem to rule out predation by even the biggest snakes.
      Another article I consulted mentioned otters as predators of adult common snapping turtles. Apparently this happens while the turtle hibernates. In Wisconsin where I live, it's not too unusual to find living specimens which have lost a limb or tail. This is said to be the result of predation by raccoons.
      In all this I’m talking only about adult snapping turtles. Young ones, of course, are taken by many predators.

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    2. PS-To be clear about the python question, I’m saying the rigidity of the shell would seem to rule out effective constriction. I realize the snake wouldn’t actually need to crush the shell. As we know from research recently discussed here, the important effect of a constricting attack is the circulatory shock. A turtle with an extremely rigid shell would seem to be immune to this effect, in my opinion.

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  4. You wrote:
    a. "In all this I’m talking only about adult snapping turtles. Young ones, of course, are taken by many predators."
    In Harry W. Greene's book "Snakes - The evolution of mystery in nature" (University of California Press, 1997), we read about Indigo Snakes (Drymarchon corais):
    "One individual contained three mices, two small Common Snapping Turtles (Chelydra Serpentina), and two Mexican Burrowing Frogs (Rhinophrynus dorsalis) [...]" (page 196).

    b. "A turtle with an extremely rigid shell would seem to be immune to this effect, in my opinion."
    Since the topic is as interesting as controversial, I have given a look at some snake books.
    1. In Mark O'Shea's "Boas and Pythons of the world" (Princeton University Press, 2007), there's a photo of a Green Anaconda that is trying to crush a River Turtle. Probably, the turtle is Podocnemis unifilis, a large species - it can reach a lenght of 70 cm - with a rigid shell. The caption reads as follows: "Green Anacondas" (Eunectes murinus) are well known to take mammals and caimans, but a river turtle?!".
    You can see the above-mentioned picture (and others more) here:
    http://www.arkive.org/green-anaconda/eunectes-murinus/image-G58206.html
    The caption reads: "Green anaconda suffocating a fresh water turtle".
    However it is unclear if the snake actually managed to kill the turtle.
    Here is an article concerning another similar case:
    http://www.deathandtaxesmag.com/190492/2-horrifying-snake-attacks-captured-in-the-last-month-pics/
    As you can read, the anaconda fails to kill the turtle.

    2. In Chris Mattison's "The New Encyclopedia of Snakes" (Princeton University Press, 2007), we read:
    A. "Turtles must rate highly on the list of indigestible food items but are not completely overlooked. Among the species eaten by snakes are musk turtles, a common snapping turtle, box turtles, two species of sliders [...]" (p. 104);
    B. Eunectes murinus [...]. Its prey includes freshwater turtles [...]. (p. 205).
    Now, if it's true that anacondas take river turtles (also adults ones), I wonder in what way they are able to kill them.
    If these turtles, thanks to their rigid shells, are immune to both circulatory shock and suffocation, how do anacondas overwhelm them?
    Gordon, what do you think?

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    1. This is fascinating. Possibly the “small” snapping turtles taken by indigo snakes have been juveniles, but I agree an animal that capable of swallowing river turtles (as the green anacondas do) is probably capable of swallowing snapping turtles as well.

      I suspect there’s a big difference in behavior, though, between river turtles and snapping turtles. I only know river turtles from reading, but my understanding is that they eat only vegetable matter and invertebrates. A common snapping turtle is an active carnivore, capable of taking fish and small snakes. I have seen video of a captive specimen taking adult rats. There are also cases on record of snappers biting off children’s toes and injuring the fingers of adult humans. I think, therefore, that the snapper is far more formidable than the river turtle and might give a big constrictor more trouble.

      It’s possible that snakes don’t kill the turtles before eating them, but instead swallow them alive when the turtles remain defensively retracted for a long time. The snake might treat the turtle as dead and go ahead with consuming it. This might be a safe proceeding with the river turtle, which I believe defends itself by folding its head sideways into its shell. The common snapping turtle does not retract into its shell and depends to some extent on biting and clawing attackers. I’m not sure if other species of snapper—the ones found in the anacondas’ range—have the same habits as the common snapping turtles I’m familiar with—perhaps they are not so formidable. If they are similar, though, I could imagine them being too much trouble for most snakes to bother with.

      In theory it’s possible for a snake to drown a turtle. That would take considerable patience, but I don’t see any reason why it wouldn’t eventually work, assuming the snake manages to keep its own head above water and avoids getting badly bitten. Big constrictors are far more powerful than even a common snapping turtle.

      It’s too bad the Mattison book isn’t more specific. He seems to imply that adult snapping turtles are taken as prey. I have ordered a copy of this book and will see if I can trace his sources.

      I should also mention that American alligators often eat hard-shelled turtles. My only hesitation about whether they eat adult snapping turtles is the size; but that does not seem to be an impediment to the green anaconda.

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  5. "A common snapping turtle is an active carnivore, capable of taking fish and small snakes."
    Take a look at this picture:
    http://www.arkive.org/common-snapping-turtle/chelydra-serpentina/image-G135783.html
    The snake seems to me a rattlesnake, but I can't understand whether it is a young one or an adult one.
    What's your opinion?
    Still on the subject, in a book of mine there's a photo of a snapper turtle taking an Indigo Snake. If you're interested in seeing it, I send it to you via e-mail. ;-)

    "It’s possible that snakes don’t kill the turtles before eating them, but instead swallow them alive when the turtles remain defensively retracted for a long time. The snake might treat the turtle as dead and go ahead with consuming it."
    I wonder how die a turtle or another prey swallowed alive by a snake: they die suffocated inside the stomach of the reptile? But, if so, isn't it risky for the snake do it this way?
    For example, a snapper turtle or a river turtle swalloved alive might bite and claw the stomach of the snake, killing it.
    What do you think?

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  6. That looks like an adult rattlesnake in the photo. Impressive! i'd definitely be interesting in seeing the photo with the indigo snake.

    I often hear stories of prey injuring snakes from inside. It's not clear to me whether this really happens with any frequency, but I snapping turtle swallowed alive would certainly be dangerous to the snake. In that video of a snapper eating rats (which unfortunately has been removed), the turtle often sliced the rats in half with a single stroke of its claws. I imagine it would do serious harm to the snake.

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  7. "I often hear stories of prey injuring snakes from inside"
    Do you remember which species of snakes?
    I ask you this question because it would be interesting to know if these accidents happen more often to constrictor snakes or to venomous ones.
    Although both are known to swallow sometimes prey alive, the injection of venom is generally regarded as a method of killing more effective than constriction: therefore, venomous snakes should in theory be less exposed to injuries from inside.

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    1. I don’t recall, Max. I suspected they were mere folklore, so I didn’t treat them too seriously. Perhaps it really happens on occasion, but I think non-scientific observers may assume a prey item has clawed its way out when they see a snake with a burst abdomen. But that sort of injury is surely more likely to happen in various other ways, such as the eruption of gases caused by decomposition. But I think any snake which swallowed a live snapping turtle would find itself in danger of internal damage.
      On another subject—I looked into the Mattison book you mentioned. I see he is talking specifically about the water moccasin (Agkistrodon piscivorous) as having eaten a snapping turtle. This is a species I’m familiar with, and I feel certain it is not capable of swallowing an adult snapping turtle. Its neck is fairly narrow, even though its body becomes more robust further back. However, the published list I have looked at in Venomous Reptiles of the United States, Canada, and Northern Mexico by Ernst and Ernst do not specify whether the snapping turtles found in A. piscivorous stomachs were juvenile. The Animal Diversity Web (http://animaldiversity.org/accounts/Chelydra_serpentina/) lists several predators of the common snapper, but claims their size and pugnacity put the adults beyond threat from most predators.

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  8. "This is a species I’m familiar with, and I feel certain it is not capable of swallowing an adult snapping turtle."
    I completely agree with you. I think it is much more likely the reverse situation: adult snappers that prey on young or adult water mocassins (and other snakes).
    This should also apply for Chelydra serpentina's larger "cousin": Macroclemmys temmincki, the Alligator Snapping Turtle.
    With regard to the said species, in the book "Stalking the Plummed Serpent", the author - herpetologist Bruce Means - tells when, on a night in 1974, a "monstrous alligator snapping turtle" hurted him to his left hand.
    "My poor hand - he writes - bleeds from cuts inflicted by the sharp sides of the turtle's jaws and I can't open my fingers without additional pain".

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    1. That's interesting. I more often hear of people bitten by the common snapping turtle, but it's not surprising the alligator snapper can hurt a human when necessary.

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  9. In The Animal Diversity Web, on the snapper's page that you reported, I read a statement that I find strange: "Snapping turtles kill other turtles by decapitation. This behavior might be territoriality towards other turtles or a very inefficient feeding behavior".
    I really don't urdestand why decapitation would be a "very inefficient feeding behavoir".
    What's your opinion, Gordon?

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    1. It may be "inefficient" to waste food, but I think it would be pretty efficient from the snapper's point of view; he doesn't waste energy trying to crack a shell when there's easier food to be found.

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  10. I can imagine what kind of battles must take place between two adult snappers! In fact, I think these reptiles are very territorial.
    I also wonder what are the interactions between Chelydra and Macroclemmys. Probably, the first - being smaller and therefore, presumably, less strong - sometimes falls victim of the second.

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    1. Perhaps those missing limbs are caused not by raccoons, but by other snapping turtles!

      I have no field experience of the alligator snapper, but many seem to feel it's less aggressive than the common kind.

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    2. "[...] many seem to feel it's less aggressive than the common kind."
      Tell that to Bruce Means! :-))

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