The Staying Power of Snapping Turtles
Sure, snapping turtles are sometimes irascible and always prehistoric-looking. But these relics, which have been around for 90 million years, are the ultimate survivors.
A young snapping turtle's fate depends upon its mother's choice of a nest site, which determines both a hatchling's size--moist earth produces larger embryos than dry earth--and its sex. Known as temperature-dependent sex determination, or TSD, the temperature of each egg midway into the first trimester of incubation influences a hatchling's sex, a trait shared with all crocodilians, many other turtles, and several lizards. Under the southern sun, which might shrivel the eggs, snapping turtles nest in the shade. Here, in the cooler Northeast, they seek full sun. Although there are TSD differences across the snapping turtle's broad geographic range, mostly males develop at temperatures between 70 and 75 degrees Fahrenheit and mostly females above 84 degrees or below 70 degrees. A clutch of eggs may produce mostly females on top, where it's warmest, and on the bottom, where it's coolest, while males dominate in the middle of the nest. Nests with a uniform temperature may yield a single sex.
Carroll sees a snapping turtle's life, even that of the biggest, scariest-looking turtle in the pond, as filled with obstacles. Hibernating snapping turtles, with some of their meaty anatomy exposed, are inviting targets. Otters, Carroll says, root out these comatose and defenseless victims and chew off their legs and tails.
Avoiding prowling humans is another story. People hunt and trap large snappers for their meat, of which there is plenty. In the Midwest and South, there's a large commercial market. Historically, Carroll tells me, snapping turtle soup was popular in Philadelphia, and it still is in some places. When I attended college in Indiana, I bought a can of turtle soup in a local grocery just to give it a try, but it proved to be bland.
"I've never eaten it," Carroll says. "I can't eat my brothers."