Did you know that the sex of a turtle is determined by the temperature of the nest where a female turtle lays her eggs? Warmer temperatures lead to more female turtles, while cooler temperatures make males.
That’s leading to some concern that global warming could cause all the painted turtles to die off: A study by the Naturalist found that a rise of even 1.1 degrees celsius could make all painted turtles hatch as females. Although I do wonder if they might just wait until a bit later in the season to lay the eggs so that they’ll get a higher male population. Not sure if they’ve studied that yet.
Learning about this trait in the painted turtle, which I spotted on a trip to Watkins Glen State Park in the Finger Lakes back in August 2011, made me wonder if other species share this characteristic.
I discovered that it’s fairly common among some types of reptiles, including other turtles and members of the crocodile family. Fish and amphibians also can have gender influenced by incubation temperature. With some species, cooler temperature led to more females and warmer to more males, exactly the opposite of the painted turtle’s pattern. In other instances, warm and cool temperatures lead to females, while mid-range temps mean males. It’s all very fascinating.
I spotted painted turtles again on a more recent trip this summer when we stopped by Hancock, Maryland, on our way to Washington, D.C.
We walked along the C&O Canal trail and after crossing a bridge, quickly happened upon what appeared to be hundreds of turtles and frogs in the murky, algae-infested waters. They were covered in algae, sunning themselves on rocks. They were a bit skittish and jumped off the rocks quickly. They were pretty though under all that muck, with bright orange and red that helps to distinguish them from other turtles.