‘Tis the season when turtles are leaving the comfort of their watery homes to set off cross country to find the ideal place to bury their eggs. For several of them, it appears that place is the grass ring where I ride or the field next to it, where I also ride. It amazes me that these determined creatures get so far on their stubby little legs; the pond is a fair distance from where they are digging their egg holes. Couldn’t they find a closer spot that would also be suitable?
I have therefore instructed Zelda in the art of not stepping on the turtles, which are roughly the size of one of her hooves. It’s an exercise akin to ground poles but with an element of surprise. You often don’t see them until you are right on top of them. So far, we have achieved success. No turtles have been injured while they lay their eggs.
For those of you who don’t have painted turtles (like the one in my photo), the females lay their eggs in late spring/early summer. The female digs a nest and lays just 4-10 eggs. That’s not a whole lot when you consider all the predators that consider turtle eggs a great delicacy. It takes the perfect combination of heat and humidity in the nest to incubate the eggs, and the temperature in the turtle nest determines if the turtles are male or female.
Eggs incubated at constant temperatures of 30 and 32 °C produced females only, whereas those kept at 22, 24, and 26 °C produced males only. Both sexes occurred at 20 and 28 °C. The threshold temperatures (temperatures producing 50% males) were estimated to be 27.5 and 20.0 °C, and were similar to those reported for more southerly populations of C. picta.Sex determination in Northern Painted turtle
Approximately 72 days later, the tiny turtles hatch and head back to the water. Years ago, my husband and I were walking on a trail in Massachusetts and we found about a dozen baby turtles. We were entranced by them — until we figured out they were snapping turtles! Those might be cute when young, but they grow up to be vicious. I’ve also found a baby turtle (just one) in the parking lot of my local supermarket. I managed to rescue him or her before it was crushed by a car.