REPTILES
Status: Common, Native Resident

SNAPPING TURTLE
(Chelydra serpentina)

 Description 

Snapping turtles are the largest turtles in South Dakota. The top shell length is usually 8 to 12 inches (20-30 cm), with a
record length of 18.5 inches (47 cm). Snapping turtles cannot retract their head into their shells because their shells are
reduced in size, covering less of their bodies than do those of other turtle species. The massive adults weigh 10 to 35 pounds
(4.5-19 kg). Their coloring is variable, ranging from light green and brown shades to very dark green and brown. Snapping
turtles are easy to recognize by their large head, powerful jaws, and long tail, which is saw-toothed along the top. Another
identifying characteristic is their aggressive behavior when threatened while out of water. Snappers have a hooked upper
jaw and no teeth and, as their name indicates, will snap at prey or attackers. Their hard beak has a rough cutting edge that
they use to tear food. 

 Distribution 

Snapping turtles are found throughout South Dakota where there is adequate habitat of quiet or slow-moving water with a
muddy bottom and vegetation. 

Natural History

Any large or small, permanent body of fresh water is a potential home for a snapper. They can be found in lakes, ponds,
marshes or slow-moving streams. Largely nocturnal , snapping turtles spend most of their time underwater, lying on the
bottom. They often bury themselves in mud in shallow water with only their eyes showing. Camouflaged with their
mud-colored skin and algae-covered shell, snapping turtles lie in wait and ambush their prey. However, they can also be
aggressive predators. They are omnivorous , eating various small aquatic invertebrates, crayfish, snails, fish, frogs, toads,
snakes, bird eggs, small mammals, and carrion. About a third of their diet is plants. Small prey are swallowed whole and
large prey are torn to pieces with their large, powerful jaws and sharp claws. Like most turtles, snappers can go for days or
even weeks without eating, but when food is available they will eat all they can and may become quite fat. Snapping turtles
become more sedentary as they age and they can live to 60 years old.

Because their bottom shell is so small, snapping turtles can't pull themselves into their shells to protect themselves from
predators. Instead, their best defense is a strong offense. They are very aggressive and threatening when confronted on land.
When threatened, they raise their bodies and lunge fiercely at an intruder with their jaws open. They also produce a very
unpleasant odor.

Snapping turtles are reptiles and, like all reptiles, they are cold-blooded. Many aquatic turtles bask to gather warmth from
the sun. Snappers rarely bask on land as most other turtles do, but may bask on the water surface. They survive the winters of
South Dakota by hibernating . As the temperatures drop they get less and less active. Finally, they burrow deep into the mud
at the bottom of ponds. Scientists have found that the blood of hibernating turtles actually changes to function like antifreeze
used in car radiators. As a result, the turtle's body temperature can drop to only a few degrees above freezing, which is much
lower than that of most animals that hibernate.

Male snapping turtles mature at 3 to 5 years and females at 4 to 6 years. Mating usually takes place in water early in the
summer. Although snapping turtles breed in the water, their eggs are laid on land. Female snapping turtles often have
traditional nesting areas and they are known to journey 10 miles (16 km) in order to reach the nesting site. Twenty to 30 eggs
are laid in a hole in moist soil about 4 to 7 inches (10 -18 cm) deep that is dug with their hind legs. The eggs are round,
shelled, and about an inch (2.5 cm) in diameter, about the size of a small golf ball. Once the eggs are laid, the female turtle
has completed her maternal tasks and returns to her pond or stream.

The turtle eggs often hatch in the fall after an incubation of 2 to 3 months. If the eggs are laid late in the season, they may not
hatch until the following spring. The incubation temperature of the eggs determines the sex of the hatchlings. Males result if
the eggs are maintained within the temperature range of 72 to 82 degrees F. (22-28 degrees C). Snapping turtle eggs produce
more females at incubation temperatures outside of this range. As soon as they have hatched, the young turtles make their
way to water. They grow quickly and may reach 6 inches (15 cm) in shell length within their first year. Many of the
hatchlings become prey to raccoons, skunks, snakes, bullfrogs, herons, and other large birds.
 

Management Considerations

Snapping turtles are long-lived and important members of the aquatic food chain as prey and predators. They continue to be
found in many wetland habitats. Because they prey on many amphibian and invertebrate species that are sensitive to
pollution and water quality, it is important that wetland quality is maintained. In some areas of the country snapping turtles
are economically very important. Large numbers are caught for making soups and stews. To collect snapping turtles in South
Dakota, you need a fishing license. Anglers are limited to 2 snapping turtles per day and a possession limit of 4. It is illegal
to buy, sell or trade turtles for any purpose other than personal consumption.

Glossary

Aquatic - living or growing in, on, or near fresh water.
Carrion - dead or decaying animal matter.
Hibernate - to pass the winter in a dormant or inactive state with lowered metabolism and heart rate.
Invertebrate - animals that lack a backbone, such as worms, insects and clams.
Nocturnal - active at night.
Omnivorous - eating both animal and plant.
Sedentary - remaining in one locality, not moving around very much.

References

Conant, Roger, 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Boston: Houghton
Mifflin. 2nd ed. Peterson Field Guide Series.
Halliday, Tim and Kraig Adler, ed., 1986. The Encyclopedia of Reptiles and Amphibians. New York: Facts On File.
Smith, Hobart M. and Edmund D. Brodie, Jr., 1982. Reptiles of North America. Racine, Wisconsin: Western Publishing
Company, Inc. (Golden Field Guide).

Resources for Teachers

Caduto, Michael and Joseph Bruchac. Keepers of the Earth: Native American Stories and Environmental Activities for
Children. Golden, CO: Fulcrum Press. 1988.
Caduto, Michael and Joseph Bruchac. Keepers of the Animals: Native American Stories and Wildlife Activities for
Children. Golden, CO: Fulcrum Press. 1991
Aquatic Project Wild has several excellent activities related to turtles.

Written by:
Donna Graham, Rapid City, SD 57701. 1997.

Illustrated by:
Kathy Colavitti, independent artist, Green Bay, WI.

Reviewed by:
Doug Backlund and Steve Thompson, Resource Biologists, S.D. Department of Game, Fish, and Parks, Pierre, SD.

Publication of the Snapping Turtle fact sheet was funded by the South Dakota Department of Game, Fish and Parks, Division
of Wildlife, Pierre, SD.