 |
|
Rattlesnakes Do rattlesnakes cause you to get all rattled up? Rattlesnakes are amazing animals! While rattlesnakes have a bad reputation, in truth people and rattlesnakes don't often come in contact with one another so people aren't bitten very often. But if you do meet up with one, be careful! Did you know that a rattlesnake can bite a victim even after its head has been removed? Scientists say that its a reflex action (a response that is built into its nervous system and doesn't need to be learned). Rattlesnake heads have been known to make their striking motions for up to one minute after decapitation.
|
| Animal Communication |
|
Did you know that snakes hiss when disturbed, and
that the volume of their hiss is determined by their size? As a rule, the rattlesnake will lie quietly until disturbed.
Th Rattlesnakes have very poor eyesight. If they cannot see their prey, they react to movement. They do not hear sounds, but they sense vibrations. A rattlesnake picks up vibrations with its jawbones. They cannot hear their own rattle, so it is believed that they rattle in order to warn other animals that they have come too near. The rattling tail may be a nervous reaction to their perception of danger.
|
| Physical Characteristics |
|
Rattlesnakes always lift the end of their tail when they rattle. Eastern diamondback rattlesnakes are among the heaviest of all snakes. They weigh up to 20 pounds and are up to 8 feet long. The smallest rattlesnake is the pygmy rattlesnake which is only about 18 inches long. The diamondback gets its name from the diamond designs on its back.
Every rattlesnake has a rattle. When they shed their skins, which is necessary for Rattlesnakes have triangular shaped heads that are flat and wide with narrow bodies covered with tough plates called scales. Scales on their backs and sides have ridges in the middle called a keel. Belly scales are smooth and much larger. Pygmy rattlesnakes, like nonvenomous snakes, have nine large scales on the tops of their heads. The color of their skin is determined by their habitat. (For example, rattlesnakes of the Grand Canyon are pink.) The rattlesnakes skin has three layers: the bottom layer holds the color, the second layer holds the scales, and the third layer is thin enough to cover the snake's eyes and still allow it to see. It is this third layer that is shed several times a year to allow for growth. Every rattlesnake has a rattle and fangs. When their fangs are not in use, they curl back into grooves on the top of the rattlesnake's mouth. When they attack their prey, strong muscles in the mouth squeeze the poison sacs near the back of the head which causes venom to travel through the fangs and into the animal.
|
| Habitat |
|
Rattlesnakes live in the mountains and deserts from southern Canada to South America. Enemies or predators of the rattlesnake are roadrunners, coyotes, and foxes in the desert, and owls and hawks in the woodlands or forests. Only 4 out of 31 species of rattlesnakes do not live in North America. Like a camel, a rattlesnake can store water inside its body which helps with desert living. They also adapt in the desert by becoming nocturnal, as the daytime ground reaches temperatures that are fatal. The only North American states that are not inhabited by rattlesnakes are Alaska, Hawaii, Delaware, and Maine. The majority of rattlesnakes live in the Western United States and Mexico. Although people most often think of rattlesnakes as just being in the desert, they can also be found in the woodlands and the prairies. Rattlesnakes prefer to live in places where there are rocky ledges or deep crevices. (Deep crevices are especially found in the northern regions, where snakes will need to hibernate.)
|
| Food |
|
Rattlesnakes eat rodents, birds and other small mammals. They also eat lizards and
Different rattlesnakes appear to have different food selections and choices of foods may change as the snake ages. This is somewhat determined by the
strength of their venom which increases in toxicity as they age. Rock rattlesnakes favor poisonous
centipedes. Small diamondbacks eat lizards and change to rodents and rabbits as they age. Snakes always swallow their prey head first, making it easier to swallow. |
| Growth & Reproduction |
|
Mating usually occurs in the spring after hibernation. If there are no males present, a female will leave a scent trail leading to her den. If there are multiple males, then the males "wrestle." They stand on their tales and bump into each other, but do not bite. The one left standing gets the girl. While mating, the male and female entwine tails. The female (who is usually bigger and stronger) will take the male to wherever she wants to go. After mating, the males leave for their summer feeding grounds and the female remains at the den until the babies are born. After birthing her young, it is likely that the female will die during hibernation as she In July, August or September, a mother rattlesnake will typically birth her young. They are born with a knob at the end of the tail called a prebutton. The mother stays with the babies 1-2 weeks until they shed their skin for the first time. When they do this, the first rattle appears; it is called a button. The button is silent as there must be two or more rattles to shake against each other to make sound. The female Pacific rattlesnake can lay 2-20 eggs of which 9-10 babies will live. It has been said that a female snake will eat her young to protect them from predators. Babies are born close to hibernation time, and the mother will leave a scent trail to the den to assist them in finding it. When they come out of hibernation, they are very hungry. The rattlesnake grows during
its entire life depending on how well it eats. Growth is related to how many times they shed their skin in a year. Every time they shed their skin, they get a new rattle, so the number of rattles is not determined by how old it is, but rather
by how many times it has shed its skin. The most rattles ever observed on a wild snake was
sixteen. |
| Other Interesting Facts |
|
A rattlesnake's rattle is made of the same material as your hair and fingernails (keratin which also makes a rhino's tusk). Even dead rattlesnakes can be fatal, because if you step on their fangs you could be in contact with the venom. The scientific name of all rattlesnakes begins with crotalus or sistrurus which means "rattle tail." When it comes to biting,
rattlesnakes are very accurate. In a study of rattlesnake strikes,
the rattlers landed a strike in 20 of 21 attempts.
|
| Citations |
|
Books Berman, Ruth. Buzzing Rattlesnakes.
Minneapolis: Lerner Publications Co. 1998. Lavies, Bianca. The Secretive Timber Rattlesnake. New York: Dutton Children's Books. 1990. McDonald, Mary Ann. Rattlesnakes. Minneapolis: Capstone Press. 1996. Stonehouse, Bernard and Esther Bertram. The Truth about Animal Communication. New York: Tangerine Press. 2003.
Townsend, Emily Rose. Rattlesnakes. Mankato, Minnesota: Pebble Books. 2004. Whitfield, Philip ed. MacMillan Illustrated Animal Encyclopedia. New York: MacMillan Publishing Company. 1984. Periodicals "Dead Snake Heads Attack?" Current Science 10/8/99, Vol. 85 Issue 3: p12. Lambeth, Ellen. "Rattlers!" Ranger Rick May 1998, Vol. 32 Issue 5: p18. "Science Snacks." Current Science 11/20/98, Vol. 84 Issue 6: p3. Online Resources
"How Dangerous are Rattlesnakes?" American International Rattlesnake
Museum - Albuquerque, New Mexico. 20 December 2005. <http://www.rattlesnakes.com/info/danger.html>.
"Rattlesnakes." Desert USA The Ultimate Desert Resource. 6 December
2005.
<http://www.desertusa.com/may96/du_rattle.html>. Images Permission to use photograph of rattlesnake showing rattle at top of this page is granted under the terms of the GNU Free Documentation License from Wikipedia, the Free Encyclopedia. <http://en.wikipedia.org/wiki/Main_Page>. Permission to use copyrighted photographs of all
other rattlesnakes on this webpage from Desert USA. <http://www.desertusa.com/may96/du_rattle.html>: Copyrighted animation of rattlesnake with cowboy hat and photograph of desert from "Classroom Clipart" <http://classroomclipart.com/> February, 2006. Images can be used solely educational purposes in K-12 classrooms. Copyrighted image of snake sticking
out tongue and animated frog from "Microsoft
Office Online" <http://office.microsoft.com/clipart/default.aspx?lc=en-us&cag=1>
|
en it uses it's rattle (a group of up to a dozen hollow, dried-skin shells on the end of it's tail) to warn other bigger animals that it is
near. The noise of the rattle is produced by segments of the rattle bumping against each other. When rattling, the rattle may rotate up to 60 or more times in a second! The rattle sounds like dried bones clicking together. It can be heard up to 30 feet away. Sometimes, but not usually, the rattlesnake will give no warning before it strikes. People often confuse rattlesnakes with nonpoisonous snakes because their rattle can sound like just a regular snake rustling
its tail in the grass and leaves. 
A rattlesnake can smell in two ways: with their nose and with their tongues.
Every time their forked tongue is out of their mouth, they pick up dust from the air and ground.
When the tongue is back inside their mouth, it rubs against taste
detectors called Jacobson's organs. This allows rattlesnakes to follow scent trails, find prey and to recognize other snakes. They also have heat sensing pits between their nose and eyes which allow them to
locate prey. They move their heads back and forth to use these pits to pick up where the strongest heat is coming from. Even in the dark, the rattlesnake is very accurate when it
strikes.
growth,
all of the skin comes off except some that stays attached at the end of
the tail. The first part of a rattle that forms is called the
button. The next time the snake sheds, the button stays stuck to
the end of the tail and a new section is added beneath the button.
This keeps happening with each section fitting loosely over the one
under it. The noise is made when the sections of skin rattle
against each other. The rattle grows and can be up to
two inches long. 
Rattlesnakes are well suited to life as a hunter.
They move smoothly and quickly across rocky terrain and even through water. They have many rib pairs connected to a flexible backbone by strong muscles. Their hearts have
three valves, unlike humans who have four. Other organs are shaped to fit in their slender bodies. Their lungs act as a storage place for air which helps them float when they move across water. They have a multi-purpose opening on the underside of their body, which serves to dispose of waste, for mating and for birthing babies in female snakes. They also have folds that open and stretch when they swallow food.
The folds are located on their throat and stomach. This allows them to eat prey that is larger in diameter than they are.
Their basic habitat is mountains, swamps, grasslands and
deserts. In cold areas, the rattlesnake will hibernate in dens during the winter months. They can take over other animal dens or find crevices in rocks. If they do not find a den before winter sets in, they will die.
frogs. They most often strike and
the let go of their victim as the venom works so quickly that their prey cannot go far. If they strike birds however, they have to hang on. The
eastern diamondback has even been known to eat other snakes.
does not eat before they are born and she may not have enough time after they are born to consume enough food to last the winter. Unlike most other snakes, rattlesnakes give birth to 6-20 live young at a time. Like other snakes, they lay eggs, but unlike others they keep the eggs inside of their bodies.