SNAPPING TURTLES: Chelydridae

PHYSICAL CHARACTERISTICS

Snapping turtles are large, unfriendly turtles that have strong, clawed legs; a powerful bite; and a long neck. With its long neck, the snapping turtle can quickly swing its large head far forward as well as sideways and back over the upper shell. These turtles also have a long, strong tail with a row of ridges. The upper shell, or carapace (KARE-a-pays), has three keels, or ridges, but older turtles usually lose the keels and have smooth shells. The lower shell, or plastron (PLAS-trun), is quite small, which allows the turtle to move its legs easily. The length of an adult's upper shell ranges from 7.1 to 31.5 inches (18 to 80 centimeters), and the lower shell may be only about one-fourth that size. Females weigh about 4.4 to 5.5 pounds (2 to 2.5 kilograms). Males generally are larger than females and can weigh as much as 249 pounds (113 kilograms).

GEOGRAPHIC RANGE

Snapping turtles live in North America, Central America, and South America, from southern Canada to Ecuador.

HABITAT

These turtles mainly live in permanent water bodies, ones that are filled with water all year long. Some are able to survive in somewhat salty waters, but they typically prefer freshwater. Although they spend the majority of their time in the water, they will travel quite a distance over land to nest, and one species makes overland trips from one watering hole to another.

DIET

Snapping turtles are primarily meat eaters, dining on almost anything they can find, whether it is alive or dead. The diet includes worms, insects, snails, and larger items, such as other turtles, ducklings, and small mammals. Although it is not common, some turtles can live on an all-plant diet.

BEHAVIOR AND REPRODUCTION

Most people know snapping turtles for their unfriendly personality. The turtles can quickly strike out with their long necks and powerful jaws and snap at any passing animals, whether it is a fish or other prey they want to eat or a person who comes too close. Instead of teeth, they have a hook at the front of the upper jaw that helps in grasping and then tearing apart prey. Snapping turtles occasionally sunbathe, or "bask," on land, but more typically they float just below the water's surface and soak up the warmth there. Snapping turtles that live in warmer climates are active day and night all year long, but those that live in cooler areas usually are active only during the day and typically spend the cold winter months buried in the muddy bottom of a waterhole.

During the breeding season, the female digs a hole on land, sometimes near the water and at other times quite far away, in dry areas. There, she lays up to 109 round eggs and buries them. Snapping turtles provide no care for the eggs or the young that hatch from the eggs. The outdoor temperature controls the number of males and females in each batch of eggs.

SNAPPING TURTLES AND PEOPLE

Although snapping turtles are not especially friendly, they are of little threat to humans who do not bother them. Humans hunt the turtles for food and occasionally for the pet trade.

THE LURE OF THE TURTLE

Besides being the biggest member of the snapping turtle family, the alligator snapping turtle has another interesting feature. It uses a bit of flesh on its tongue to draw in hungry fishes. This "lure" not only looks like a pink worm but also wiggles like a worm. When a fish approaches to nab an easy lunch, the turtle quickly lashes out and clamps its strong jaws around the unsuspecting fish. Besides fishes, this turtle's diet includes snails, clams, plant roots, other turtles, birds, and even small alligators.

CONSERVATION STATUS

The World Conservation Union (IUCN) lists the alligator snapping turtle as Vulnerable, which means that there is a high threat of their extinction: they could die out entirely. There are many sources for these threats, including too much hunting of them and the loss of good habitat.

SNAPPING TURTLE (Chelydra serpentina): SPECIES ACCOUNT

Physical characteristics: The snapping turtle, or snapper, is a fairly large member of this family. The upper shell is up to 19.3 inches (49 centimeters) in length. The shell is dark, usually black to greenish-brown, and frequently covered with green, slimy algae (AL-jee), or plantlike growths. The upper shell and the long tail have a series of ridges. The shell ridges become less and less noticeable as the animal ages. Snapping turtles have large heads with a hook on the upper jaw.

Geographic range: Snapping turtles live in North America, Central America, and South America, from southern Canada to Ecuador.

Habitat: These turtles typically live in plant-filled, shallow, calm waters with mucky bottoms. Most make their homes in freshwater areas, but some live quite well in somewhat salty waters.

Diet: Like most members of this family, the snapping turtle eats mostly meat. It is not a picky eater. Snapping turtles will eat earthworms and leeches; clams; insects and spiders; frog eggs, tadpoles, and adult frogs; reptiles, including other turtles; ducklings and other small birds; small mammals; and almost any dead animal they come across. Plants are not uncommon, and some populations of turtles even live by eating only plants.

Behavior and reproduction: Despite its usually slow walking speed on land, this turtle is amazingly swift when it comes to striking out with its powerful jaws to grab a passing animal as a meal or to defend itself against a large attacking animal or a person who is just a bit too curious. With its long neck, this turtle can swing its head forward, sideways, and backward almost half as far as it is long, and its powerful jaws can deliver a nasty bite to a person's hand or fingers.

For the most part, the snapping turtle stays in the water, where it spends most of its time sunbathing or hunting for food. To sunbathe, or "bask," the turtles float in warm water near or at the surface. Rarely, a snapper will bask on shore on a log or rock. They often hunt by hiding in the muddy bottom to wait for a tasty treat, like a fish or tadpole, to swim by. They also hunt by slowly walking along the water bottom and looking for their next meal. Turtles living in warmer climates are active day and night and all year long. Those living in cooler, northern areas are mostly active early and late in the day and spend the colder months buried underwater in the mucky bottom.

Mating season runs from spring to fall. Some males may sway their heads in front of females to attract them, but usually the males skip courtship altogether. Females lay one batch of eggs a year. Sometimes they make their nests, which are just holes they dig in the ground, close to the water, but they also may travel great distances, in some cases nearly 10 miles (16 kilometers). Females can lay six to 109 round, white eggs; they typically lay about thirty-two eggs per nest. The eggs hatch in about seventy-five to ninety-five days, but sometimes they hatch in as little as two months or as much as six months. Nest temperature controls the sex of the newly hatched young turtles. High and low temperatures produce females, and moderate temperatures produce males. Because a female can lay so many eggs at a time and the nest is so large, some parts of the nest may be warmer or cooler than others. This often means that females will hatch from one part of the nest and males from another.

Snapping turtles and people: Humans hunt snapping turtles for their meat. Many turtles also die each year from being hit by cars as they cross roads to move from a water hole to a nesting site and back.

Conservation status: These turtles are not threatened, although many snapping turtle eggs are destroyed each year when raccoons and other mammals dig up the freshly laid nests and eat the eggs. ∎

FOR MORE INFORMATION

Books:

Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Knopf, 1979.

Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual Guide to the World's Wildlife. London: Dorling Kindersley, 2001.

Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and Amphibians: Eastern and Central North America. Boston: Houghton Mifflin, 1998.

Harding, J., and J. Holman. Michigan Turtles and Lizards: A Field Guide and Pocket Reference. East Lansing: Michigan State University Museum, 1990.

Hickman, Pamela. Turtle Rescue: Changing the Future for Endangered Wildlife. Richmond Hill, Ontario, Canada: Firefly Books, 2004.

O'Keefe, M. Timothy. Sea Turtles: The Watcher's Guide. Lakeland, FL: Larsen's Outdoor Publishing, 1995.

Pritchard, P. C. H. The Alligator Snapping Turtle: Biology and Conservation. Milwaukee, WI: Milwaukee Public Museum, 1989.

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. Boston: Houghton Mifflin, 2003.

Web sites:

"Common Snapping Turtle." Chesapeake Bay Program. http://www.chesapeakebay.net/info/snapping_turtle.cfm (accessed on September 14, 2004).

Dillon, C. Dee. "The Common Snapping Turtle" Tortuga Gazette 34, no. 3 (March 1998): 1–4. http://www.tortoise.org/archives/snapping.html (accessed on September 14, 2004).

LeClere, Jeff. "Snapping Turtle: Chelydra serpentine." Iowa Herpetology. http://www.herpnet.net/IowaHerpetology/reptiles/turtles/snapping_turtle.html (accessed on September 14, 2004).