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Giant Snapping Turtles – Size Records from a Survey of 84,000 Turtles

Hello, Frank Indiviglio here.  Stories concerning immense Snapping Turtles (Chelydra serpentina) abound wherever this impressive reptile occurs, but most are difficult to substantiate.  I’ve kept and observed this species from childhood.  Once I embarked upon a career in herpetology, I had the good fortune of meeting a great many impressive Snapping Turtles and Snapping Turtle researchers, and was able to gather information on some true giants (I’ve encountered fewer Alligator Snapping Turtles, but one under my care weighed 206 pounds!).  Today I’ll highlight some interesting facts and figures concerning larger-than-average snappers.  I’d also like to draw your attention to a late-breaking threat to their survival.  Sadly, a bill currently before the NYS Assembly will, if passed, allow commercial trapping of this magnificent animal.  Please see below for further information, and check out this posting by turtle conservationist Allen Salzberg (scroll down to “Snapping Turtles under Attack”) for information on how to register your opposition to this ill-advised legislation.

Snapper smile Record-Sized Snappers

The largest Snapping Turtle I’ve handled tipped the scales at 68 pounds, and added more weight over time (please see photo).  Its “straight line” carapace length was 18.6 inches (“straight line” means that the measurement was taken via calipers, as is done for published accounts; stretching a tape measure over the shell’s curve adds to the measurement).  The largest wild-caught individual appears to be a 22 inch-long 76.5 pound behemoth captured in New Hampshire (most record-sized Snappers and Alligator Snappers originate from the northern part of the range).  Turtles artificially fattened in captivity, such as the 82-86 pound animal frequently cited in field guides, are known.

How Common are Giant Snapping Turtles?

I gleaned the following information from conversations with colleagues and various reports.  The turtles involved were collected in the northeastern USA, for the commercial food market, over a 28-year period ending in the early 1990’s.

Of 84,000 Snapping Turtles recorded, only 160 weighed 50 pounds or more.  Amazingly, twenty two 50+ pound turtles were collected from a single lake, in a single day (this, of course, is very disturbing, and bodes terribly for the species…please see below).  Of these 160 turtles, 3 or 4 topped the 60 pound mark.  A 67 pounder held the record as the largest wild-caught snapper until the appearance of the 76.5 pound individual mentioned earlier.  Since that time, another of 68 pounds has been collected.

All of the 50+ pound Snapping Turtles were males.  The heaviest female on record weighed 44 pounds.  Female Alligator Snappers are also substantially smaller than males, which may weigh over 200 pounds.  As far as is known, no female of this species has exceeded 70 pounds in weight.

 

Large Urban Snappers

Common Snapper

Uploaded by Frank Indiviglio

If undisturbed, Snappers often adapt to urban and suburban situations.  I found two huge males (on land) near the Bronx River, on the grounds of the Bronx Zoo.  One, which had an injured jaw, was quite emaciated but still weighed-in at 49 pounds.  I installed him in an outdoor pond near the zoo’s Reptile House, where he recovered and “filled out” (see this article ).

Another male of 45 pounds or so was taken to Social Tee’s Animal Rescue, a wonderful facility operated by good friend and reptile expert Robert Shapiro.  The reactions of passersby as we attended the huge beast on an East Village (NYC) sidewalk outside Social Tee’s were most amusing; please see this article.  Several of the largest animals I’ve seen were taken from surprisingly small bodies of water on Long Island, NY.

 

An Imminent Survival Threat: Please Help!

As mentioned, legislation now before the NYS Assembly would legalize the trapping of Snapping Turtles.  Currently, snappers may only be taken via gun or longbow in NY.  Trapping is much more effective than hunting, and could quickly place this iconic reptile, which has beaten the survival odds even in NYC, in jeopardy.  Legalized trapping would also result in the incidental capture of rare and endangered species such as Wood, Bog, Blanding’s and Spotted Turtles.

Hatchling Snappers

Uploaded by Frank Indiviglio

In the mid 1990’s, I spearheaded a project that sought to document mercury levels in Florida Soft-shell Turtles offered for sale in NYC food markets.  Dangerous levels were found, but red tape and other factors intervened and nothing of substance was accomplished.  Snapping Turtles have also been shown to accumulate toxins, but this seems not to be of concern to the NYS Senate, which has already passed the trapping bill (the Assembly has not yet voted…please see the link in this article’s Introduction if you wish to help).

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

 

Further Reading

Keeping Snapping and Alligator Snapping Turtles

Snapping Turtles in Brackish Water Habitats

2 comments

  1. avatar

    Hello Frank
    Firstly let me say your posts are very very interesting and educational, so I am very glad people like you exist to share your enthusiasm and knowledge!
    So I am wondering could I ask your advice on the subject of the true size of common Snapping Turtles?
    Do you personally believe that record 76.5lbs and 22 straight carapace shell size?? If so is that a one off freak of nature or do you believe they do grow this size or bigger? The reason why I ask this is of personal interest to me because in September 2005 I rehomed a unwanted Common Snapper witch I believe was handed into the zoo, and would have been put down humanly but a friend of my family thought he would rehome it, it had a 38mm straight carapace then, and over the past 9 years has out grown his tank half a dozen times, his straight line Carapace is now 17.5 inches, so basically I dident expect him to get this size and even this season alone has grown 1.75 inches alone and that’s the slowest rate of growth per year so far! So my question is when do you think he will stop growing? Should I prepare myself now for a 22inch carapace 86lbs monster in a few years time? I feed every third day, Turkey, Trout, or a Rat, is this good or bad? I would really Appreciate your reply as no one else seems to be able to give me a answer, and you seem to have a lifetime of experience with Common Snappers!
    marckenny@gmail.com
    Many thanks . . . Marc

  2. avatar

    Hello Marc,

    Thanks for the kind words and interesting info.
    The 76.5 pound 22 inch animal is for real…a colleague of mine at the BZ, and I believe the former curator also, looked into this carefully. The 82-86 pound animals often mentioned were captives.
    There seems to be lots of variation among populations; genetics and diet likely involved…some swamps /lakes consistently produce huge animals (the trapper mentioned took 22 50+ lb animals from a single lake in a single day), others always seem to be populated by small adults. but there are those unique individuals…i.e. some of the huge males I’ve found in the Bronx River, where almost all are moderately sized, as far as I can tell after many decades of experience there.

    You can expect yours to get heavier..length seems impossible to estimate. Trout and other whole freshwater fishes are ideal; they take carrion in the wild…an occasional meal of turkey meat would be fine, but try to stay with whole animals. I avoid furred rodents, although again they are taken in the wild..but digestion is a complicated process, and impactions could theoretically be possible. larger sized turtle chows are excellent…look into ZuPreem…they make a pellet suitable for large snappers. Crayfish, nighcrawlers etc are useful. I also use “seafood mixes” available at markets, especially in Korean/Chinese neighborhoods….mixed squid, fish, crab, shrimp, conch etc. Some marine-based foods are fine. Please keep me posted, and enjoy, Frank

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About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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