Original Wild Facts, Reptiles

Wild Fact #793 – Heads it’s a Boy, Tails it’s a Girl – Yellow-Spotted River Turtle

http://commons.wikimedia.org/wiki/File:Podocnemis_unifilis.jpg

I was having a tough time deciding which animal to talk about today when it dawned on me that I haven’t talked about a turtle in a long time.  So today we get to look at the Yellow-Spotted River Turtle.  I recommend you grab your coffee (or juice in a sippy cup for our younger audience), sit back and enjoy the presence of this super cool turtle.

So what makes the Yellow-Spotted River Turtle so super cool?  Well, it is a turtle and all turtles are awesome. I also think it is pretty interesting that these turtles live in the Amazon River basin.  During the wet season though they will also venture out to hang in the flooded forest. I guess if you are a terrestrial animal like a squirrel then you would start to worry when you see the turtles moving in. For some reason, I picture an old, cranky squirrel yelling at his wife, “Martha! Martha! Pack your nuts, the Turtles are here.  We are heading for the hills!” Wow, it must have been a long day for me. I highly recommend you keep reading since I have no idea what else I might say today.

The Yellow-Spotted River Turtle is a type of side-necked turtle which can weigh up to 25 pounds.  For the record, it is the female turtle that weighs the most in this species.  I just realized that I didn’t explain what a side-necked turtle is.  Would you like to know? Of course you would.  Well, the side-necked turtles aren’t like your typical turtle.  You know the ones that pull their heads straight back to hide in their shell.  Nope, these guys simply bend their necks sideways and tuck their head under the lip of their shell.  From what I can tell from this description, the Teenage Mutant Ninja Turtles would have been your typical type of turtle.  Well, as typical as a mutant turtle can be.

Yellow-Spotted River Turtles – The sex of this particular turtle is determined during the very early stages of their life (obviously!).  Believe it or not the temperature that the eggs incubate at will actually determine if you are having a boy or a girl.  Eggs incubated below 32 degrees Celsius (90 degrees Fahrenheit) will produce male turtles.  I am sure you can guess that eggs incubated above this temperature will produce females.

Well that is all for me folks.  Have a great day!

9 Comments

  1. Hi Nathan!

    Just caught-up on your last four posts – summertime and the liven is busy! Enjoyed everyone of them. Thank you for making the information so interesting.
    Glad to hear you have decided to visit Africa, you will not regret that trip.

    1. Hi Aunt Linda!

      Summer is a very busy time but it is a good busy. I am glad you are enjoying the Wild Facts. For the record, I can’t take credit for the interesting information. The animals are the ones who make it interesting.

      I am incredibly excited to visit South Africa. I think I will be based out of Cape Town for part of the trip. What parts of Africa did you visit?

  2. I love reading your blogs….you put a smile on our face first thing in the morning. You put just the right amount of humour in the fact to keep us chuckling.

  3. “Martha! Martha! Pack your nuts, the Turtles are here.

    You have to stop drinking before you write these blogs. Like for real.

  4. Thank you for the interesting fact Nathan!

    I am very curious about the temperature of the water affecting the sex of the turtle. Why do you suppose this would have evolved?

    Thank you!

    Celine

    1. This is an excellent question, Céline. I had to conduct a little bit of research to find a definite answer for you.
      Several animal species will use temperature (or other external factors) to determine their gender. It is usually reptiles but some fish and birds will also use this technique. As we know, mammals (i.e. humans) use chromosome-based methods to determine the gender. So what is the advantage?

      About 30 years ago Eric Charnov and James Bull hypothesized that “Temperature-Dependent Sex Determination (TSD)” will occur when the temperature of the environment of that species will greatly impact the success of males or females. This simply means that throughout evolution, male Yellow-Spotted River Turtles will have a better chance surviving an environment with a temperature below 32 degrees Celsius than their female counterpart. The opposite is also true for the females when the temperature is higher than 32 Degrees Celsius. Basically, this allows the turtles to predict the future and give their species an edge. They are able to produce more males during conditions that are better suited for males and vice versa for females. If you think about it, this is a pretty sound way to survive a tough environment.

      This hypothesis has been proven and I will attach the link to the journal article, however, I think you will need to pay for a subscription to read it all. If you are looking for more than I recommend typing in “Charnov-Bull Model” into your favourite search engine.

      I am not sure how well I explained this topic so please don’t hesitate to ask additional questions.

      Thanks again for an intriguing question.

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