The United States has the most turtle species out of any country in the world (51 species). Common snapping turtles (Chelydra serpentina) are one of the most easily identified of these 51 species. In 5th grade, our class pet was even a snapping turtle baby that someone had found in a parking lot. They have a wide range of areas that they live in North America; basically all of the U.S. minus the west coast and Texas. Sadly there is also a wide range of misconceptions to go along with their wide geographic range. The biggest misconception is that they are aggressive and should be killed if seen. Others have negative views of the turtles because they kill game fish, which is true but have a minimal impact on populations. Generally, they are only aggressive on land as it is hard for them to walk on land. They tend to only be found on land during the breeding season when females go in search of sandy patches in which to lay their eggs. These sandy patches are often found along roads. If you see a snapping turtle in the road if you decided to move you should know they have a long reach with their neck and their claws are also very sharp. Typically I just stand in the road with the turtle until it safety crosses. If the turtle is a baby you can carefully pick it up and place it near a waterbody where it can hide from predators.
Common snapping turtles have a shell length between 8 to 14 inches, but their tail can be nearly as long as the shell. They weight between 10 to 35 lbs, however, a record common snapping turtle weighted in at 75 lbs. They can live in fresh or brackish water but they prefer areas with vegetation and muddy bottoms as it makes it easier for them to hide. Sometimes the turtles bury themselves in the mud with only their nostrils sticking out so that they can ambush prey. Unlike the painted turtle (Chrysemys picta) or red-eared slider (Trachemys scripta elegans), they do not like to bask in the sun and prefer to stay in the water. As I said before, they are really only found on land during the breeding season between April and November. Females lay between 25 to 45 eggs. The higher the latitude, the greater number of eggs laid. Most of these eggs will not make it to adulthood, meaning they are an r-selected species. On average they live 17.8 years but have been documented to live as long as 47 years in captivity. Their density in the environment is related to how much food is available and the presence of other turtles. Male turtles will fight and all common snapping turtles will kill other turtle species by decapitation. They are omnivores and consume a wide range of items from aquatic plants to common loon (Gavia immer) chicks.
Common snapping turtles are prized for turtle soup-making by some. Native Americans used their shells to make musical instruments as well. Young turtles are also often caught as pets or even exported to other countries. In 2008 the US export over 500,000 individuals. However, data does not indicate how many of these turtles were from the wild vs farmed. The turtles are also heavily impacted by pollution such as pesticides, heavy metals, and industrial chemicals. They are considered a bio-monitoring species because they are so sensitive. Despite some exploitation of the turtles, their populations remain very stable. IUCN considers the turtles to be a species of “least concern” and based this statement on the factor that over 3 generations the turtles have not seen a 30 percent range decline and is not likely to approach this level anytime soon. Further hope for the turtles includes data related to Michigan turtles. In the 1980s the turtles were heavily trapped for 2-3 years and that led to population declines. However, by 2009 the population was almost entirely recovered.
Some of the common snapping turtle range also overlaps with the alligator snapping turtle (Macrochelys temminckii). The alligator snapping turtle has distinct ridges and points on its shell, is larger and has a triangle shaped head. They also are considered a vulnerable species while common turtle populations are stable. There is also a Central American snapping turtle (Chelydra rossignonii) but this turtle is found only in Belize, Guatemala, Honduras, and Mexico. The South American snapping turtle, on the other hand, is also found in a different geographic range than the other species; Colombia, Costa Rica, Ecuador, Honduras, Nicaragua, and Panama. New Guinea, Papua New Guinea, Australia also have other species of snapping turtles. These turtles look similar to new world terrapins.