DO ALL REPTILES HAVE TAILS?
March 7, 2010
that a question was asked by a second-grader does not mean it is uninteresting,
nor does it mean the answer is simple.
do all reptiles have tails?
Kipling offered fanciful explanations for the how and why of many natural
marvels in his "Just-So Stories," but he did not address the
issue of why all reptiles have tails. Perhaps Kipling realized that no
single answer would suffice because the tails of reptiles are used for
use their tails in defense. The tails break off when caught by a predator,
allowing the rest of the lizard to escape. I once saw a king snake stalking
a brown skink, a small lizard that lives among ground vegetation in the
Southeast. When the snake finally got close enough to strike at the lizard,
the lizard scurried away beneath the ground litter. Yet the snake had
a mouthful of lizard--the wiggling tail. By the time the snake finished
its snack, the lizard was long gone. The venomous Gila monsters of the
Southwest are also lizards, but their enormously fat tails are not detachable.
The Gila monster uses the tail to store energy during periods when food
is scarce. An African chameleon uses its tail as if it were a fifth foot,
to hold onto limbs when climbing.
also have tails that enable them to hold onto branches or vines to assist
them in climbing trees. A rattlesnake uses its tail as a warning device
when it feels threatened. Many harmless snakes also vibrate their tails,
and if they happen to be lying in dried leaves, they too make a rattling
sound. Baby copperheads and cottonmouths use their tails in an intriguing
way. When they are born, and for a few months afterward, they have bright
yellow tips on the ends. When the snake is coiled, the tail points up
from the center and serves as a lure for prey. Small lizards and frogs
apparently think the tail looks like a worm ready to be eaten.
dark-colored snakes, such as mud snakes and ringneck snakes, the underside
of the tail is brightly colored; when threatened, the snake displays the
tail, which is in conspicuous contrast to the rest of the body. The sudden
display of color can startle a prospective predator. As the dark-bodied
snake begins to crawl away, it lowers its tail, and some predators may
then be searching for a bright color instead of one camouflaged against
the dirt or mud, allowing the snake to escape. Rubber boas of California
have short, blunt tails that look almost identical to the head. When threatened
by a predator, this snake arranges its body in such a manner that the
tail is exposed while the head is hidden safely beneath the snake. The
predator that bites the-tail-that-looks-like-a-head is in for an unpleasant
surprise. The boa squirts a foul-smelling liquid from the tail region
that would make any predator lose its appetite.
and crocodiles use their flat-ended tails to propel themselves through
water. Some sea snakes that spend almost their entire life in the water
also have flattened tails that aid in swimming. Some crocodilians use
their tails to knock prey off the bank and into the water.
As a rule,
turtles do not use their tails for any of the purposes mentioned for other
reptiles. Nonetheless, having a short, blunt tail, rather than no tail
at all can be vital for a turtle. Adult male turtles, which generally
have longer, stouter tails than females, use their tails to hold onto
the female's tail during the mating process.
uses of reptile tails provides insight into some of the ecological purposes
to which an appendage can be put. And the second grade is not too early
to want to know why the creatures of the world are the way they are. Ecology
is often a matter of simple questions and complex answers. Not as whimsical
as Kipling's explanations, but every bit as fascinating.
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