New World Pond Turtles: Emydidae

views updated

NEW WORLD POND TURTLES: Emydidae

PAINTED TURTLE (Chrysemys picta): SPECIES ACCOUNTS
EASTERN BOX TURTLE (Terrapene carolina): SPECIES ACCOUNTS

PHYSICAL CHARACTERISTICS

The New World pond turtles come in many shapes and sizes. Adult small bog turtles have upper shells, or carapaces (KARE-a-pays), that grow to about 5 inches (12.7 centimeters) in length, while the carapaces of the large Gray's sliders can reach a length of 2 feet (61 centimeters) or more. Most pond turtles have a least a little webbing between their toes. The males and females look very much alike, though sometimes the females are larger. In some species, the male is more colorful and has long, thin front claws.

GEOGRAPHIC RANGE

Members of this family live in North and South America, Europe, western Asia, and northern Africa.

HABITAT

New World pond turtles may live in tropical areas, where it feels like summer all year, or in cooler areas that have all four seasons, including winter. These cooler areas are known as "temperate climates." Many turtles spend almost their entire lives in or near ponds, lakes, and other freshwater areas, though some can live quite well in saltier waters. Other species live their lives mainly on land.

DIET

Depending on the species, New World pond turtles may eat meat, plants, or a combination of meat and plants. Sometimes, baby turtles begin their lives as meat eaters but start to munch plants as they grow older. The meat eaters may dine on such animals as fishes, tadpoles, insects, worms, and slugs. Turtles that eat plants prefer grasses, flowers, and berries. They also eat algae (AL-jee), or tiny plantlike growths that live in water.

BEHAVIOR AND REPRODUCTION

Many people have seen these turtles, because most of the animals in this family like to sunbathe, or "bask." Turtles that live in the water typically climb up onto a rock or log sticking up above the water's surface and soak in the sunshine. Often, many turtles will climb onto the same rock or log and may stack up on one another. Turtles that live on land simply find a sunny spot and bask there. Many of these turtles are active all year, but those that live in temperate climates sink underwater and bury themselves in the muddy bottom or bury themselves in shallow holes or under piles of leaves to wait out the winter. Some that live in areas with long, dry spells also become inactive until the rains come again.

During breeding season, usually in the spring, the males try to attract the females by bobbing their heads or waving their front claws in front of a female's face. After mating, the female finds a dry spot onshore, sometimes up to 0.6 miles (1 kilometer) away from the water, and digs a hole. She lays as few as one egg and as many as two dozen eggs in the hole and then covers them up. Afterward, she provides no care for the eggs or the young. As with most turtles, the temperature of the nest controls whether the egg becomes a male or a female turtle. Warm nest temperatures produce females, and cool temperatures produce males. The eggs hatch in about two to three months.

COUNT THE RINGS

In many turtles, including some New World pond turtles, a person can tell how old a turtle is by counting its rings. The rings are on the upper shell, which is split into little sections, called scutes (SCOOTS). Wood turtles, for example, have five scutes down the middle of the shell and another four on each side. Every year the turtle gets a new set of scutes, which grow underneath the old ones; they stack up in a pyramid shape, with older and slightly smaller scutes on top. By counting all of the scutes in one pile, a person can guess the age of the turtle. Sometimes the oldest scutes wear away, so the turtles may actually be a little older than their scutes reveal.

NEW WORLD POND TURTLES AND PEOPLE

People enjoy seeing turtles in the wild, but the numbers of many New World pond turtles are dropping. People once collected and killed these turtles to eat their meat. While that practice is not as common anymore, turtles still face threats from too much collecting for the pet trade or from car traffic on roads they cross to reach a pond, nesting site, or other area.

CONSERVATION STATUS

According to the World Conservation Union (IUCN), six New World pond turtles are Endangered, meaning that they face a very high risk of extinction in the wild. Seven species are Vulnerable, meaning that there is a high risk that they will become extinct in the wild, and fourteen are Near Threatened, meaning that they are at risk of becoming threatened with extinction in the future. The U.S. Fish and Wildlife Service lists the Alabama red-bellied turtle as Endangered and three other species as Threatened. Pollution, collection for the pet trade, and destruction of habitat, or the areas in which the turtles prefer to live, are major reasons that the numbers of these turtles are low. In addition, raccoons and other animals often dig up nests and eat the turtle eggs.

PAINTED TURTLE (Chrysemys picta): SPECIES ACCOUNTS

Physical characteristics: The painted turtle is a medium-sized turtle that is mostly olive or black on the legs, head, neck, and upper shell. Adults can grow to 3.5–10 inches (9–26 centimeters). The head has yellow stripes, and there are both red and yellow stripes on the neck and legs and red striping around the edge of the upper shell, the carapace. The bottom shell, or plastron (PLAS-trun), is yellow or tan, with a long, dark blotch running down the middle. Males and females look very much alike, except that the females are larger and the males have longer and thinner front claws. A large female's carapace can reach almost 10 inches (26 centimeters) in length.

Geographic range: These turtles are found in Canada and the United States.

Habitat: Painted turtles are mainly freshwater animals, although a few live in saltier waters. They prefer waters with little, if any current, or swift-moving water. They live in southern Canada and mostly in the far northern, central, and eastern United States, though a few populations live in the southwestern United States and just over the border in Mexico.

Diet: Painted turtles are not picky eaters. Their meals consist of plants, insects, snails, leeches, tadpoles, and small fishes that they find in the water. They will also eat dead animals. Young turtles are mainly meat eaters and then switch to eating more and more plants as they grow older.

Behavior and reproduction: The painted turtle spends much time sunbathing, or "basking," on logs or rocks that poke up out of the water. During the winter months, which can become quite cold in the northern part of their range (the region where they roam and feed), they bury themselves underwater in the muddy bottom and wait for spring. If the winter day is warm enough, they may crawl through a hole in the ice and bask before returning underwater. Males and females mate in the fall or in the spring. The male attracts the female by tickling the sides of her head with his long claws. The females leave the water from late spring to midsummer to nest on land, usually somewhat near the water. The nest is a hole she digs in the ground. She lays one to twenty eggs in each nest and typically makes one or two nests a year. Nest temperature controls the number of males and females in the clutch. The eggs hatch in seventy-two to eighty days.

Painted turtles and people: Most people know these turtles as the ones they see basking on logs in lakes and rivers. Some people collect the turtles for the pet trade, and a few eat their meat.

Conservation status: Painted turtles are not threatened, but many of them are killed every year by raccoons and other animals that dig up their nests and eat the eggs or by cars that run over the turtles as they attempt to cross roads. ∎

EASTERN BOX TURTLE (Terrapene carolina): SPECIES ACCOUNTS

Physical characteristics: The eastern box turtle is a small- to medium-sized turtle with a rounded upper shell. The adult's lower shell has two hinges. When the turtle is frightened, it can pull its head, legs, and tail into the shell and use the hinges to close up the lower shell. The carapace is black with a pattern of short yellow stripes. Males have red eyes, a longer and thicker tail than that of the females, and a lower shell that is indented rather than flat. Females are larger than males and have carapaces that can reach 9 inches (23 centimeters) in length.

Geographic range: Theses turtles live in the United States and Mexico.

Habitat: This species lives in much of the eastern half of the United States and parts of Mexico near the Gulf of Mexico. It is a land turtle that roams forests and fields.

Diet: Eastern box turtles eat a variety of plants and animals, including grasses, flowers, and berries as well as insects and earthworms.

Behavior and reproduction: These turtles live on land, so they cannot swim away from danger, and they are not fast runners. To protect themselves against predators (PREH-duh-ters), or animals that might want to eat them, the adults tuck their legs, tails, and heads inside their shells and use the hinges in the upper shells to close up tight. Predators cannot get through the sealed shell. Young turtles, however, do not have hinges. Instead, they release a strong odor that persuades predators to leave them alone. Like other members of this family, eastern box turtles sunbathe to warm up. When the day gets too hot, they hide just barely underground. In the winter months these turtles bury themselves beneath a pile of leaves or just under the soil and wait until spring. Sometimes, if the winter becomes particularly cold for a few days, a turtle will freeze, and its heart will stop beating, but they do not die.

Males and females mate in the spring. The male attracts the female by biting at her shell and sometimes her head and bumping into her. Females lay their eggs from spring to midsummer, sometimes making five nests a year, though most of them make just one or two. The female lays one to eleven eggs in each nest, and the eggs hatch in about two and a half months. The nest temperature controls the number of males and females in each nest. A warmer nest produces all females, and a cooler nest produces all males.

Eastern box turtles and people: This turtle is popular in the pet trade because of its size and friendly behavior. People rarely see them live in the wild, except when the turtles attempt to cross a road—an activity that too often results in death from a passing car.

Conservation status: According to the IUCN the eastern box turtle is Near Threatened, meaning that it is at risk of becoming threatened with extinction in the future. Habitat loss has caused some of the drop in turtle numbers. ∎