We’re over halfway through May, and we all know what that means: it’s almost World Turtle Day!
World Turtle Day is May 23, a day to celebrate and protect turtles and tortoises.
And there isn’t a better way to celebrate than by learning more about one of the largest turtles we have in North America: the common snapping turtle.
Common snapping turtles (Chelydra serpentina) are large freshwater turtles that live in the central and eastern parts of the United States and up into southern Canada. They can get pretty big, with the average adult coming in with a shell 8 – 12 inches long and weighing in at 10 – 35 pounds.
Common snapping turtles are omnivores and eat pretty much anything. A large part of their diet comes from plants, but they will also hunt fish, amphibians, reptiles, and birds. In addition, snapping turtles eat a large amount of carrion; this means they perform a vital role in the river ecosystem by cleaning up dead bodies.
Common snapping turtles have been around for a long, long time. They evolved back when the dinosaurs were around (90 million years ago) and survived the mass extinction even 65 million years ago that wiped the dinosaurs off the face of the earth. This makes them one of our oldest turtles!
Snapping turtles haven’t evolved much since the dinosaurs, and they look pretty much the same as they did 90 million years ago.
Even though common snapping turtles are common, you won’t notice them in your daily life. First, common snapping turtles are primarily nocturnal, so they spend most of their time wandering at dusk and dawn.
Secondly, common snapping turtles really like to spend their time submerged at the bottom of a river. They prefer to live in water with muddy bottoms and lots of vegetation so they can stay hidden in the mud. In fact, they can hold their breath for up to three hours at a time!
Common snapping turtles spend so much time in the water that their shells grow a layer of algae; this provides a further layer of camouflage. And unlike other turtles, which like to bask in the sun on logs or rocks in the river, common snapping turtles prefer to stay in the water when getting some sun. You’re most likely to see them floating at the water’s surface with their shell and snout in the air.
Has a bad rap
Snapping turtles are known for being aggressive, but their ferocity is wildly overstated.
When snappers are in the water, they are actually pretty docile. They are unlikely to swim after you to attack; instead, they prefer to swim away from potential threats.
Still, common snapping turtles can quickly turn to violence when on land. Since they are too big to fit into their shells and hide, snapping turtles resort to biting when they feel threatened out of the water. This behavior is purely defensive, though, and as long as you give a snapping turtle space, it shouldn’t bother you.
In addition, a common snapping turtle’s bite is less impressive than you think. They can bite down with a force of around 656 newtons (N), but a typical bite is just 209 N. In comparison, we can apply about 1300 N between our second molars!
Still, you shouldn’t underestimate a snapping turtle. They can strike quickly and even behind themselves! Adding to their fearsome strike, snapping turtles have a long reach – their necks can stretch 2/3 of the length of their shells! And their beaks are sharp, perfect for shearing flesh, so even a bite with comparatively little force will still hurt!
Female common snapping turtles will lay 20 – 40 eggs in a nest dug in the sand near a body of water. After laying her eggs, the female will return to the water – her eggs and eventual hatchlings are on their own. Unfortunately, these nests are prime feeding grounds for animals like raccoons, skunks, and crows. As many as 90% of nests are destroyed by predators.
Common snapping turtle eggs are highly dependent on where they are laid. For example, moist dirt makes larger embryos than dry dirt. The ambient temperature is also important, as the eggs will hatch sooner in warmer temperatures.
In addition, like many other turtles, common snapping turtles have temperature-dependent sex determination (TSD). This means that the temperature an egg is incubated at determines the eventual sex of the hatchlings. Eggs kept at 68 degrees Fahrenheit produce only females. A moderate temperature of 70 – 72 degrees Fahrenheit results in both male and female hatchlings. Finally, warmer temperatures (73 – 75 degrees Fahrenheit) will produce only males.
Once they hatch, the young turtles have to make it to the water without getting eaten by predators. They are also snacks for fish and other snapping turtles in the water. However, suppose the hatchlings can survive these treacherous early months. In that case, they are virtually predator-free, given their size and thick shell!
Meet the internet’s current favorite snapping turtle: Chonkosaurus.
Joey Santore was kayaking on the Chicago River when he spotted Chonkosaurus, a snapping turtle that probably weighs about 40 pounds.
Why is Chonkosaurus such a big deal (besides the fact that seeing a 40-pound turtle is cool)?
Because for a long time, the Chicago River was a dumping ground for industrial waste and pollution. The return of snappers like Chonkosaurus means that efforts to clean up the river are working – the wildlife is returning!
True, common snapping turtles can survive in polluted areas relatively well. But seeing such a large turtle is a good sign, and more, less resilient animals may eventually come back as the Chicago River continues to get cleaned up.
So as you celebrate World Turtle Day, maybe see if you can find a snapping turtle. It may not be as big as Chonkosaurus, but who knows? Perhaps you’ll discover Chonkosaurus Jr.!
Connecticut Department of Energy & Environmental Protection
North Carolina Wildlife Resources Commission
Forest Preserve District Will County
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