What's climate change ruining now?: The sex lives of painted turtles

The sex of these turtles is determined by the temperature of the nest while the baby turtles are still egg-bound. The warmer the nest, the more likely the turtles end up female. The warmer it gets in the American Midwest, the more painted turtle society turns into whatever the opposite of a sausage fest is. Now, depending on your personal inclinations, you could argue that this might actually improve turtle sex — but it definitely puts a damper on creating new generations of baby turtles.


    1. This^.  A problem has actually been solved. A useful term has been born. Nothing else on BoingBoing today will rival this happening. 

  1. “Painted” turtles? Sounds like slut-shaming an entire species just for wearing makeup.

  2. From http://en.wikipedia.org/wiki/Fisher%27s_principle


    Suppose male births are less common than female.

    A newborn male then has better mating prospects than a newborn female, and therefore can expect to have more offspring.

    Therefore parents genetically disposed to produce males tend to have more than average numbers of grandchildren born to them.

    Therefore the genes for male-producing tendencies spread, and male births become more common.

    As the 1:1 sex ratio is approached, the advantage associated with producing males dies away.

    The same reasoning holds if females are substituted for males throughout. Therefore 1:1 is the equilibrium ratio.


    So the eggs that have a genetic predisposition to become female at higher
    temperatures will have better mating prospects, and will pass that
    predisposition on to their offspring.

    1. I think there are situations where that breaks down, and even situations where runaway disequilibrium causes an entire species to switch to parthenogenesis.  I swear I’m not making this up, but I read it years ago.

      Also, clambake.

      1.  I’m sure there are.

        But it hasn’t reached that situation here yet, and probably never will.  There isn’t a set temperature where, once crossed, all the eggs hatch male.  Instead, they start getting a higher proportion of males, but the females are still there.  Also, wikipedia tells me that they can live for up to 55 years in the wild.

        This doesn’t mean that there won’t be a short-term disruption of sex ratios, but rather that things will eventually adjust.

  3. I saw a pair of painted turtles getting it on in Massachusetts over the weekend.  Climate change is a lie, I tell you.  A lie!

  4. How do we know these “painted turtles” even exist? Couldn’t any turtle be “painted?”

    Sounds like another attempt by “science” to bring about Nancy Pelosi’s dream of covering up Benghazi by making everyone drive an electric car, worship Karl Marx and practice Sharia Law  while getting on-demand abortions and sex changes.

    Why can’t we leave fossil fuel companies alone?

  5.  I have seen a few painted turtles as I walk the canals and bayous of Houston. I have always assumed that they are released captive bred turtles. Good to know they can’t breed down here and become an invasive species. Sad to know that climate change may kill them off in their native habitat. I suppose sliders will move in to take up the slack, so there will still be turtles.

    But please, let nothing threaten my freshwater leatherbacks. These are freaky amazing turtles. Flattest turtle you ever saw, like an alien from Flatland. Global warming has served them well so far, but I fear if they move northward they will drive other species to extinction.

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