The Ornate Box Turtle
Pond and marsh turtles of North America include the box
turtle, chicken turtle, diamondback terrapin, map turtle, painted
turtle, red-eared turtle, spotted turtle, and wood turtle. Many of
these species are brightly colored, with green, red, or yellow
markings on their head, legs, and shell. Most pond and marsh turtles
found in the United States are small, but some kinds may grow more
than a foot (30 centimeters) long. The majority of pond and marsh
turtles live in lakes, ponds, rivers, streams, and tidewater areas.
A few species, including box turtles and wood turtles, dwell mainly
on land.
The turtle is the only reptile with a shell. Most kinds of
turtles can pull their head, legs, and tail into their shell, which
serves as a suit of armor. Few other backboned animals have such
excellent natural protection.
Turtles, like all reptiles, are cold-blooded--that is, their body
temperature stays about the same as the temperature of the
surrounding air or water. Turtles cannot be warm and active in cold
weather, and so they cannot live in regions that are cold throughout
the year. They live almost everywhere else--in deserts, forests,
grasslands, lakes, marshes, ponds, rivers, and the sea.
There are about 250 species of turtles, about 50 of which live in
North America north of Mexico. Some turtles live only on land, but
others spend almost their entire life in the sea. Most other species
dwell mainly in fresh water or live about equally on land and in
fresh water. Many turtles live their entire life within a few miles
or kilometers of where they were hatched. But large numbers of sea
turtles migrate thousands of miles or kilometers from their
birthplace.
Turtles vary greatly in size. The largest turtle species, the
leatherback turtle, grows from 4 to 8 feet (1.2 to 2.4 meters) long.
But the common bog turtle measures only about 4 inches (10
centimeters) in length.
At one time, pet shops throughout the United States sold
thousands of painted turtles and red-eared turtles yearly. But
medical researchers discovered that many of these turtles carried
bacteria that cause salmonella poisoning, a serious illness in human
beings. In 1975, the U.S. Food and Drug Administration banned the
sale of most pet turtles.
Shell. Most species of turtles can pull their head, legs, and
tail into their shell for protection. A few kinds of turtles,
particularly sea turtles, cannot withdraw into their shell.
A turtle's shell consists of two layers. The inner layer is made
up of bony plates and is actually part of the skeleton. Among most
species, the outer layer consists of hard, horny structures called
scutes, which are formed from skin tissue. The part of the shell that
covers the turtle's back is called the carapace, and the part that
covers the belly is called the plastron. The carapace and the
plastron are joined along each side of the body by a bony structure
called the bridge.
Turtles have a well-developed sense of sight and of touch.
Scientific experiments indicate that they also have a good sense of
smell, at least for nearby objects. Turtles have a middle ear and
inner ear, and a tympanic membrane (eardrum) forms their outer ear.
A turtle can hear low-pitched sounds about as well as a human being
can.
HOMEPAGE *
SYMBOLS * BOXTURTLE