Photo: Chris Johns, National Geographic
But anyway, all of these many types of rattlesnakes are native to the Americas, and their range goes from southern Alberta and British Columbia to central Argentina. Rattlesnakes are pit vipers, which means they kill their victims with venom that comes out through their fangs when they bite. The venom goes into the bloodstream of the victim, and it causes swelling, internal bleeding, really bad pain, and maybe death. Especially if you are something small, like a mouse. The venom of the Mojave Rattlesnake and some other species also causes paralysis.
Rattlesnakes can live in lots of different types of habitats. The biggest number of species live in the American Southwest and Mexico. Texas and Arizona are the states with the most kinds of rattlesnakes. There are four species east of the Mississippi River and two species in South America.
|Western Massauga Rattlesnake|
Photo: Bates Littlehale, National Geographic
The favorite places for rattlesnakes to live are in open, rocky areas. This is because the snakes can hide in the rocks and catch prey such as rodents, lizards, and insects. But some rattlesnakes live in other habitats, like prairies, marshes, deserts, and forests. What they really like is a temperature range between 80º and 90ºF (26º to 32ºC), but they can survive temperatures below freezing. Some species hibernate during the colder winter months. When this happens, a whole bunch of snakes will all get together inside an underground rattlesnake den. There might be as many as 1,000 snakes there. Also there may be be other species such as turtles, small mammals, invertebrates, and other types of snakes.
The way rattlesnakes hunt is they lie in wait until some prey comes by, or else they go out snooping in holes, sniffing out prey. When they find something, they kill it right away with their poisonous fangs. Rattlesnakes do not squeeze their prey to death the way constrictor-type snakes do. The prey is swallowed head-first because everything such as legs and wings go down easier that way. The snake can digest both bones and flesh. The best temperature for digestion is between 80º and 85ºF, so when the rattler is full, it will go curl up in the sun someplace and get busy digesting.
As most people already know, rattlesnakes have rattles at the tip of their tails, and that is how they got their name. Probably, the reason they have these rattles is to scare away predators that might want to eat them. The rattle is made up of modified scales that form hollow, interlocking segments. There are special "shaker" muscles in the tail that make the segments rattle against each other. These muscles are really fast, and can move 50 times per second, on average. Not only that, but they can go on moving for up to three hours. If you want to hear some good recordings of rattlesnakes hissing and rattling, go to this website: http://www.californiaherps.com/snakes/pages/rattlesnakesounds.html
|Western Diamondback Rattlesnake|
This species is responsible for the majority of snake bites in North America.
Photo: Clinton and Charles Robertson
When a female rattlesnake gets in the mood to mate, she starts leaving a trail of sex pheromones wherever she goes. Male snakes follow this trail by using their excellent sense of smell. The way they smell things is both with their nostrils and also by flicking little scent particles into their mouths with their tongues. In the roof of their mouths, there is something called a Jacobson's organ that carries the scent to the snake's brain.
|Two male Northern Pacific Rattlesnakes in a "combat dance"|
Photo: Dawn Endico
Anyway, after the male has caught up with the female, he starts courting her. If there is some other male snake there who also wants the same female, the males do a "combat dance" until one of them gives up and goes away. Usually the larger snake wins one of these "dances." After the snakes have mated, the female can store the sperm for several months. Which means she can mate in the fall, but wait until spring to fertilize her eggs. The baby rattlesnakes are born live, and the mother snake often stays in the nest with the young for several weeks.
Here in Missouri, one kind of rattlesnake we have is the timber rattlesnake. Sometimes it is also called a canebrake or banded rattlesnake. The scientific name for this snake is Crotalus horridus. This rattlesnake species is the only one that lives in most parts of the northeastern U.S. Timber rattlesnakes live in the biggest variety of habitats, all the way from upland forests to lowland swamps. They mostly eat small mammals, but they sometimes also eat birds and eggs.
Timber rattlers can live as long as 30 years. It can take the females up to 8 years to mature and start having baby snakes. Then, since they usually only mate once every three years, the snake population doesn't grow very fast. And that is not even mentioning all the rattlesnakes that people kill. So the range of the timber rattlesnake is smaller than it used to be, and some states list it as threatened or endangered.
The timber rattlesnake was an important symbol in the days of the Revolutionary War. Maybe you have seen those flags that say "Don't tread on me!" The snake that you shouldn't tread on is the timber rattler. Nowadays, members of the Tea Party are using this symbol again, so it is making people argue about whether it should be displayed at statehouses or on military ships or places like that.
In 2008, the timber rattler became a new sort of symbol when West Virginia adopted it as its official state reptile.
There are lots more things I could tell you about rattlesnakes, but I'm tired of writing, and you are probably tired of reading. The most important thing I didn't say yet is that if you are in rattlesnake country, you should be very careful to look where you are walking. Don't be talking on your cell phone or listening to your iPod because you will not hear a snake rattling. Startling a snake and getting bit is not a good idea because that could really hurt. Usually, if you get quick medical care, you will not die from a rattlesnake bite, but who wants to take the chance?