Snapping turtles are Iowa’s largest turtle species, but they’re so much more than their tough demeanor. Here are some things you should know about these awesome reptiles:
The environment impacts the snapping turtles’ breeding — so much so that after eggs are laid, they can take anywhere from 55 to 120 days to hatch. Females head from their home waterbodies to upland nesting sites in June. These sites aren’t at the pond the turtle lives in, but typically around places such as roads, banks, field edges or even railroad tracks.
She will use her hind legs to dig a hole, lay her eggs and then cover them up. After laying her eggs, the female will leave the nest to return to the water, leaving the eggs to incubate on their own. The number of eggs in a clutch can vary — there may be 10 to 20, but clutches with up to 100 eggs have been found. The environment then plays a role again. The hatchlings’ gender is dependent on the temperature during incubation. A high proportion of males will come from a cool nest, and a warmer nest will result in a majority of female turtles.
Since snapping turtles don’t reach sexual maturity for about 11 to 13 years, it's extra important to avoid predators as they grow. Major egg predators are raccoons, skunks and opossums. Hatchlings are hunted by hawks, snakes, herons, crows, bullfrogs and large fish. Once the turtles have a shell around three inches, they will be less susceptible to predators, because they’re more difficult to be swallowed.
Newly hatched snapping turtles are about the size of a quarter. This leaves them as an easy meal for predators. Adult snappers are quite a bit larger — they can weigh up to 40 pounds, with a shell of eight to 15 inches long.
The snap in snapping turtle
As omnivores, these turtles eat both vegetation and meat. Their name comes from the way they eat. Snapping turtles slowly approach their prey, often small fish and amphibians, and then lunge quickly — so quickly their prey doesn’t see them until it’s too late. Snappers have also been known to clean up dead animals. These shelled scavengers may also eat water birds and small mammals.
What do snapping turtles do during the harsh Iowa winters? They live underwater! The turtles’ body temperature matches the temperature of their environment. Since air gets cooler than their bodies can handle, turtles head below the water’s surface where the temperature will remain more stable throughout the winter. Once out of the air, the snappers can hibernate for up to 100 days.
With special adaptations, turtles can use their stored energy and use oxygen from the pond water. Their specialized respiration system allows them to get enough oxygen to support their needs without using their lungs. If you see a turtle basking in the sun after the winter, they’re warming up and increasing their body temperature to help restart their metabolism and return to normal, day-to-day life.
If you see a turtle crossing the road in the spring, it’s probably headed to or from its nesting spot. If it’s safe to do so, pick the turtle up or encourage it across the road in the direction it was moving. Don’t pick up the turtle by its tail, because that can cause spinal damage. Instead, pick it up (with gloves if possible) by the shell or back legs with its head facing away from you. If you see a turtle sitting in gravel, just let it be, as it’s likely nesting.