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Written by Robert Charles

RattlersA Reading A–Z Level R Leveled Reader

Word Count: 1,505

LLEEVVEELLEEDD RREEAADDEERR •• RR

RattlersRattlers

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RattlersLevel R Leveled Reader© 2003 Learning Page, Inc.Written by Robert CharlesIllustration by Cende Hill

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Rattlers

www.readinga-z.com

Written by Robert Charles

Photo Credits:Front cover, back cover, title page: Corel; pages 4, 8, 9, 10, 11, 14,15, 16, 17, 18 (bottom): www.clipart.com; pages 5, 13, 23 (both):Carl A. Hess; page 12 (top): Zoological Society of San Diego; page 12 (bottom): Hemera Technologies, Inc.; page 18: U.S. Fish andWildlife Services; page 22: John Meyer/Learningpage, Inc.

CorrelationLEVEL R

Fountas & Pinnell OReading Recovery 22

DRA 34

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Table of Contents

Introduction........................................................ 4

Where Rattlers Live........................................... 6

How Rattlers Hunt ............................................ 8

How Rattlers Move.......................................... 11

Baby Rattlers..................................................... 13

A Rattler’s Rattle ............................................. 15

Types of Rattlers .............................................. 17

Snakebite ........................................................... 19

Rattlesnake Safety............................................ 20

The Rattler’s Future ........................................ 22

Glossary............................................................. 24

Introduction

While most snakes are harmless, there are a few that can strike with a deadly bite.Rattlesnakes, commonly known as rattlers,are some of the most feared of these deadlysnakes. But before you get the wrong ideaabout rattlers, let’s set the record straight.Snakes don’t go around looking for someoneto bite. In fact, most snakes, including rattlers,would rather avoid people. And also, mostpeople who are bitten by rattlesnakes do notdie from the bite.

Resting rattlers like this one rarely bite.

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where rattlers LIVE

All of the world’s rattlesnakes are found in North and South America. They live inalmost every state of the United States, in every South American country, andthroughout southern Canada. Their habitat

You should also know that snakes have animportant role to play among living creatures.Rattlers eat rodents such as rats and mice.Since many rodents carry diseases and destroyvaluable crops and property, rattlesnakes helphumans by keeping the number of rodentsunder control. So the next time you think badthings about rattlesnakes, don’t forget thegood they do.

A rattler eating a mouse

Many species of rattlesnakes live across North and SouthAmerica. The numbers indicate the center of each territory.

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how rattlers hunt

Rattlers belong to a group of snakes calledpit vipers. Pit vipers have deep, heat-sensingpits below their eyes. The pits detect the bodyheat of rodents, birds, and other prey. A rattlercan detect the heat of a candle flame from asfar away as 10 meters (30 ft.). Rattlers also“smell” with their forked tongues by flickingthem in and out of their mouths. Using heatand smell to find food makes rattlers goodnight hunters.

includes swamps, deserts, prairies, forests,and mountains. The greatest numbers ofrattlesnakes are found in the deserts and dryareas of the southwestern United States andnorthern Mexico.

Like all reptiles, rattlesnakes are cold-blooded. This means their body temperaturegoes up and down with the temperaturearound them. Because they can’t keep theirbodies warm, rattlers spend the winterhibernating in dens below the ground. For the most part, rattlers are loners, butduring hibernation, hundreds can gather in the same den.

As spring begins, rattlesnakes crawl out of their dens to bask in the sun. As the sunwarms their bodies, the rattlers become more active and get ready to spend thesummer hunting. You are most likely to seerattlesnakes when the temperature is 21º to 30ºC (70º–90º F). In areas where it gets really hotduring the day, rattlers must find shady placesto stay cool. They often like to lie under rocks,bushes, cacti, and trees.

The pit is the dark spotabove the mouth.

Pit

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Unless the prey has a good chance ofescaping, such as if it can fly, a rattlesnake letsgo after it bites. The prey runs off, but it doesnot go far before the poison begins to takeeffect. Rattlesnake venom works in two ways.First, it affects the nerves and muscles so thatthe victim has difficulty breathing andmoving. Second, it begins to break down thevictim’s muscles and organs. By the time therattler is ready to eat its victim, digestion hasalready begun.

The snake uses its “smelling” tongue tofollow its victim. Once the snake finds itsprey, it swallows it whole and headfirst.Rattlers can separate their lower and upperjaws in order to swallow prey that is largerthan their own heads. Since snakes don’t useenergy keeping themselves warm, rattlers canlast for months on one meal.

Using their blending skin patterns, rattlershide near small trails or holes where rodents,lizards, and birds pass by. As the prey goes by,the snake strikes with its long, hollow fangs.Normally, the fangs are folded back againstthe top of a rattler’s mouth. When the snakebites, its fangs drop down and its mouthopens wide enough to drive them through theskin. Rattlers produce a poison called venomin glands behind their eyes. When the snakebites, the venom travels through tubes into the fangs. The fangs act like doctors’ needles,giving the victim a “shot” of venom.

The rattler’s fangs swingdown in preparation for abite. The illustration at leftshows the structures thatproduce venom and send it through the fangs.

Snakes cansmell theirprey in the air.

Venom gland

Fangs

The sidewinding motion is only used by a few kinds of rattlers that live in sandydeserts. It looks a lot like the serpentinemotion, only it pushes the snake sideways.

The third type of movement, the caterpillar,uses the snake’s scales. Rattlers have wide, flatscales across their bellies. The snake can use itsmuscles to lift and lower the edges of thescales. The edges dig in and push the snake’s

body forward, the waycaterpillar treads push a tractor forward.

The caterpillar motion was namedafter Caterpillar® tractors.

how rattlers move

How can something with no legs huntother animals? Rattlesnakes move in threeways. The most common is the serpentine(SERP-en-teen) method. The rattlesnakemoves its body in an S-shaped motion.Muscles along the curves push the snakeforward against the ground. This motion also makes rattlesnakes excellent swimmers.

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DO YOU

KNOW?Some snake

skeletons have verytiny leg bones.These snakes donot have visiblelegs, but the bonesindicate that snakesmay have oncehad legs.

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Sidewindingpushes thesnake’s body sideways, asopposed toforward.

The serpentine motionmoves a rattler forward (inthe direction of the arrow).

Even at birth, a baby rattlesnake has apoisonous bite. But babies do not have rattles.They cannot sound a warning. The babiesalso have less control over how much venomthey inject. In these ways, tiny baby rattlerscan be more dangerous than big adults. Onthe other hand, many predators, includingowls, hawks, ravens, coyotes, and even othersnakes eat baby rattlers.

baby rattlers

Female rattlers begin having babies whenthey are three or four years old. Rather thanlaying eggs like most reptiles, rattler mothersgive birth to live babies. Rattlers usually have10 to 12 babies each time they give birth.

After they are born, baby rattlers do notneed their mothers. However, they tend tostay close to their mothers for about ten daysuntil they shed their baby skin and begin tohunt. Baby rattlers may outgrow and shedtheir skins 3 to 4 times each year.

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Baby rattlers (left) stay near their mother until they shed their skin.

Many predators,including hawks, eatbaby rattlesnakes.

Some people think you can tell the age of arattler by the number of sections on its rattle.But older parts of the rattle break off. Thereare usually no more than ten sections. Sincerattlers can live 25 years and molt 2 to 3 timesa year, it is probably good that sections falloff. Otherwise, an old rattler might have ahuge rattle with up to 75 sections. Can youimagine how loud an old “buzztail” with arattle that big would be?

a rattler’s RATTLE

The rattle makes rattlesnakes differentfrom all other snakes. The rattle serves as awarning to any animal that threatens thesnake. Each time the snake sheds its skin, or molts, a section of hollow, fingernail-likematerial is left behind on its tail. The rattlesections get bigger as the snake grows. Whenit is afraid, the snake coils up and shakes itstail. The hollow sections clatter against eachother, making a buzzing sound. This givesrattlers the nickname “buzztails.”

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A rattler warns other animals to keep away.

Rattlers coil up and lift their heads when threatened.

Other common rattlers include thesidewinders. They get their name becausethey move across the desert sand using thesidewinder motion. Sidewinders are smallerthan diamondbacks, usually less than 1 meter (3 ft.) long.

Smaller rattlesnakes include the bandedrock and pygmy rattlers. How do you thinkthese snakes got their names?

types of rattlers

There are more than 30 types of rattlers.The largest are the eastern diamondbacks.They have been known to grow to almost 2.5 meters (8 ft.). Western diamondbacks areslightly shorter, but they can be thicker andheavier than eastern diamondbacks. Mostwestern diamondbacks grow from 1 to 1.5meters (3–5 ft.). Diamondbacks get their name from the diamond-shaped pattern on their skin.

Timber rattlesnakes can be found in manywooded parts of North America fromsouthern Canada to northern Mexico. They are about 1.5 meters (4–5 ft.) long.

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The eastern diamondback has bold patterns.

Banded rockrattlesnake (above);pygmy rattlesnake(below)

Most people who get bitten by rattlesnakes weretrying to catch, tease, or kill the snake. Rattlersare not dangerous if you follow these safety tips:

1 Never bother a rattlesnake or other snake.Snakes are wild animals, and you should nottry to catch or touch them.

2 If you go into wilderness areas where snakesmay live, wear long pants and boots thatcover your ankles. Snakes bite down low,and a layer of clothing can block a bite.

3 Keep your pets on leashes. Do not let yourdog get close to or chase after snakes.

4 Do not stick your hands or feet under rocks,logs, or bushes where you cannot see.Snakes like to hide under things.

5 If you hear a rattle, stop movingimmediately. Calmly look around and try to spot the snake with your eyes. Backslowly away from the snake. Remember,rattlesnakes are trying to warn you with theirrattle—they do not want to bite you if theydon’t have to. Pay attention to that warning.

snakebite

Other than when hunting, rattlers only bite in self-defense. Most people get bittenwhen they bother the snake or accidentallystep on it. Often, a threatened rattler gives a “dry” bite with no venom. And even if the snake does inject venom, it usuallyinjects a small amount. Rattlers aren’t tryingto kill people or animals that threaten them.They only want to hurt the person or animalenough so that he or she will go away andkeep away in the future.

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RATTLESNAKE SAFETY

A rattler in a defensive posture

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DO YOU KNOW?Antivenom, the medicine used to treat

snakebites, comes from horses. Doctors inject thehorse with a little bit of snake venom. The horse isnot hurt, but it builds up a chemical that stops theeffects of the poison. Doctors collect this chemical,which also stops venom’s effects in people andother animals.

RATTLESNAKE SAFETY

If you or someone you know is bitten, followthese steps. Follow the same steps for your pet:

1 Keep the victim calm. Panic will only makethe heart beat faster, carrying the venomthrough the body more quickly.

2 Get to a doctor as quickly as possible, butdo not let the victim run or do any otherexercise. If possible, have someone carrythe victim.

3 Put a cool, wet cloth over the bite. Do notuse ice, since ice can cause frostbite.

4 Tell the doctor or hospital workers what kindof snake you think may have bitten thevictim. But do not try to catch the snake, killit, or bring it to the hospital.

The rattlers’ future

There are far fewer rattlers aroundtoday than when Columbus landed inthe Americas. Because many peoplefear rattlers and do not understandthe good they do, they oftenneedlessly kill them. Not long ago,rattlesnake roundups were popular.During these hunts, people capturedall the snakes they could find. Thesnakes were killed and skinned.The meat was sold and the skinswere made into belts, wallets, and purses.

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The demand for beautiful snakeskin has caused the death of many rattlers. The inset photo shows the pattern of scales.

GLOSSARY

caterpillar a snake motion in which the edgesof the snake’s scales catch on theground and pull the snake's bodyforward (p. 12)

cold-blooded body temperature goes up anddown with the temperature aroundit (p. 7)

fangs long, hollow, sharp teeth (p. 9)

habitat the types of places where an animallives (p. 6)

hibernating spending the winter in a deep sleepor trance-like state (p. 7)

pit vipers snakes that have pits on their headsthat detect heat (p. 8)

prey animals that other animals eat forfood (p. 8)

serpentine a snake motion in which the snakemoves its body in an S-shape,pushing itself forward where itsbody bends (p. 11)

sidewinding a snake motion in which the snakemoves in a fast, strong S-shape,pushing its body sideways (p. 12)

venom poison that animals use to kill preyand defend themselves (p. 9)

Other things threaten the survival ofrattlesnakes. Rattlesnakes like to sunthemselves on warm roads. Cars and truckskill many of these snakes. People also destroyrattlesnake habitats as they build larger citiesand more highways.

Some people arebeginning to takeaction to helprattlesnakes survive.Many rattlesnakeroundups have beenbanned or limited.Signs alert drivers toroads where rattlesnakes may be sunningthemselves. Snake habitats have been set

aside and protected. If werespect these animals, they

will not hurt us. And aswe learn more about

rattlesnakes, we understand

why it is importantto protect them.

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