You can't define rattlesnake with a dictionary.
What a rattler is depends on who wants to know, where you grew up, where you live, what
you do for a living.
Funding for this program has been provided by Asarco Incorporated and the Arizona Game
and Fish Heritage Fund.
Asarco Incorporated, producing the metals we all need, respecting the environment we
all value.
Asarco, a proud financial partner of public television for eight continuous years.
And by the Arizona Game and Fish Heritage Fund, conserving Arizona's diverse wildlife
resources.
Rattlesnakes bite, that's a fact.
And a snake bites a whole lot worse than snagging your britches on a rusty nail.
Of course, there's more to rattlers than that.
But for most people, that one fact is what matters.
To tell the truth, how you see rattlesnakes depends as much on what you're like and what
you've got on the line as it does on them.
In parts of the country where there are lots of rattlers, folks are disposed to see them
as rusty nails, something you need to pull out, get rid of.
People of this persuasion even take the whole family to big annual affairs called rattlesnake
roundups.
Whether roundups are a good thing or not is a matter of controversy.
Back in the early 50s, they were having real hard troubles, real bad troubles with rattlesnakes
in the area, farmers and ranchers having trouble with snakes biting their livestock.
And so they began kind of a campaign to get rid of the overpopulation of rattlesnake in
this area.
And so that's basically how it got started.
J.C.'s kind of picked up on it.
At the time, there were roundups going on, but the world's largest began here.
And we've been collecting rattlesnakes now for 39 years, trying to get a little of a
hold on the population of rattlesnake in our area.
We live over in Albany, and we live along a creek bed.
And I've got three little boys, so it was time to start learning about them.
We found a couple of snakes near the house and just decided this is a good place to learn.
So that's why we're here.
They understand about the snakes.
They know that they're dangerous and stay away from them.
And this way, they get a firsthand look at them, what they sound like, what they look
like, and know enough to stay away from them.
So that's really the whole idea for us.
A rancher makes a living outdoors where the rattlers roam, and he tends to run across
rattlers at times inconvenient for both parties.
This colors your personal view of snakes.
But there's another group of folks whose careers take them outdoors, the scholars and naturalists
who go there for study.
They see with different eyes.
I think to the general public, the average person's perception of a rattlesnake relates
to it being venomous and being able to produce a serious bite.
And the context usually is of a rattlesnake in a defensive posture.
That is, with their head up, coiled, rattling, looking rather menacing to the observer.
And I think that's unfortunate because when we go out and look at our snakes, they're
not doing that at all.
We seldom ever see that.
What we see are animals quietly going about making a living, reproducing.
When they see us coming, they just sit still and then if we don't move, they lose track
of us and go about what they're doing.
And if we could just get everyone out here to see what we see, I think they might have
a totally different idea of how these animals fit into the whole picture of life on earth.
I think I see him.
Yep.
It's a black tail and the signal indicates it's our number 28 male.
In the Chiricahua Mountains of southeastern Arizona, natural history scholars have found
a way to let rattlers tell their own stories and at their own pace.
Did pretty close?
We're studying the northern black tail rattlesnake here in southeastern Arizona in the Chiricahua
Mountains.
And we use radio telemetry with little transmitters implanted in the snakes.
This allows us to relocate the snakes time and time again, day after day, which normally
would be impossible to do without that technology.
We use general anesthesia so the snakes anesthetize while this goes on.
We make an incision in the lateral body wall and implant the transmitter into the salomic
or peritoneal cavity in where the body organs are.
We close the incision.
The snake wakes up and in two, three, four, five days they're back to their normal behavior
in the wild.
Thus far we just implanted our 31st snake.
We've watched the first 25 animals for periods of up to seven years from as little as a few
weeks to as much as seven years per animal.
Just seems to be this direction.
What we see repeatedly is individual snakes using the same part of the landscape over
and over again year after year, hunting in the same general areas, hibernating the exact
same hole in the canyon wall year after year, returning to that spot in the fall, emerging
in the spring and so forth.
I get to see all the venom and all that.
That's something that we've never seen before and it's pretty weird.
We saw where they were skinning them alive and that was pretty neat.
You never realize what all's inside of a snake until you see it for live.
We sell the skins for five bucks a foot and then we cook and we sell the meat.
Usually the people that buy our garb letters, which we just bought four or five years ago,
we just started saving them because we had a person come here that wanted to buy every
one of them that we had.
Usually the Orientals, people from Asia that come here and purchase and they'll purchase
every one that we have.
None of them are wasted.
They've put them in drinks, they dry them up and use them with aphrodisiacs.
I can't tell you if it works or not.
See me in a couple of years if I need the help in that department we might have to try
some.
We estimate 20 million western diamondback rattlesnake in Texas and the total commercial
harvest was estimated at 112,000, about six hundredths of one percent.
So not much, not even denning the population.
What good are rattlesnakes?
Well, for some people the question simply doesn't come up.
When snakebite is a part of your culture, a threat to your family and livestock, snakes
are bad guys, pure and simple.
And looking for the good side of a villain doesn't come naturally, not even to preachers.
It takes someone outside the snakebite culture to look for what's good about rattlesnakes
and they find it.
Rattlesnake has one of the fastest contracting and relaxing muscles, that is to say the frequency
at which it operates.
By comparison, hummingbirds operate at about forty hertz, rattlesnakes up to about ninety
hertz.
The fastest muscles that you and I have, probably the ones extending our digits, and they're
about eight hertz or so and that's as fast as we can get.
They can really make themselves flat.
It's like a two millimeter stick or something.
It's a big snake.
Even though he's rattling right now, at probably about fifty times a second, if you just give
the slightest pressure down here, you basically make the whole thing stop.
He's still going, but even a very slight force is sufficient to stop the rattling itself.
One of the secrets of success to this animal, and it turns out it's not unique to rattlesnakes,
it's for those muscles that work very fast, including insect flight muscles, the amount
they shorten is very, very limited.
So the actual shortening distance per contraction is kept to a minimum, and that's why we see
a little bit of movement this way, but if you look at the muscle, there's almost stationaries
where the rattle is almost a blur.
So what we're going to do is now stick the EMG electrodes on each side so that we can
look at how those two muscles relate and what the electrical signal is.
The central nervous system is sending to cause the snake to rattle.
Basically the rattlesnake is a model system for us, though we're interested in the rattlesnake
per se, we're also interested in how muscle in general operates.
The rattlesnake presents a great model for us if we're interested in how do all muscles
turn on and off rapidly.
That can have tremendous implications for humans, both in terms of athletic performance,
but also in terms of some disease states.
So what we have is the electrodes are in the snake's tail.
These electrode wires then come down to this junction box.
From the junction box, they go into a preamplifier.
From the preamplifier, they go into the oscilloscope and simultaneously into our tape recorder,
which then records this signal, and we can play it back and analyze it subsequently if
we'd like.
Each spike that we see on the screen represents a single contraction.
The rattlesnake is now contracting its tail something around 40 to 50 times a second.
The other thing we can see clearly from this expanded time scale is that the muscles on
the left side of the body are exactly out of phase with the muscle on the right side.
What we're thinking happens is that the way the rattlesnake shakes its tail is that it
contracts one side followed by the other side, and those, again, two antagonistic pairs are
exactly 180 degrees out of phase.
That forces the tail to go side to side.
The actual movement, however, is very minuscule, it's very slight.
Rattlesnakes can rattle for three or four hours continuously.
That's an amazing endurance speed.
It's certainly at least the equivalent of running a marathon in two or three hours.
As physiologists, we view nature as having provided us with not only animals that are
aesthetically pleasing, but also some great model systems where we can look at individual
important physiological questions.
The rattlesnake is one of those.
We can get at some properties of muscle that we really couldn't look at as directly with
other model systems.
The shame is that currently the biodiversity around the world is actually decreasing, and
the pity is that that means that a lot of those model systems are disappearing before
we've had a chance to both enjoy them aesthetically as well as to use those models in order to
find out more about how all of us, including humans, are functioning.
There's just the things about rattlesnakes that make them special, make them unique and
different from virtually all other animals that we find in the Southwest, and something
that should attract our attention, that should make us want to learn more about them and
care more about them rather than making us want to kill them.
I'd prefer to look at one of the models of ecosystems where they liken the functional
ecosystem to an airplane, and the species may be the different rivets that hold this
plane together, and shoot, you can probably do it without a lot of those rivets.
You pull one out here and lose it here, but at some point the unity of that airplane or
that ecosystem is going to fall apart, and we just don't have enough wisdom to know when
that is.
As Aldo Leopold said many years ago, that the basic tenet of sound tankering is to keep
all the parts.
The Sweetwater Roundup isn't strictly an indoor event.
Naturally, ticket holders can also jump on a bus and go on a field trip.
We looked at a five county area right around Sweetwater as the most intensely hunted area
in the world, less than three percent harvest.
And a species as prolific as the Western Diamondback, you could probably safely harvest a third
of their numbers every year, and so, I mean, if anything, it's an underutilization of a
very prolific resource.
I was butchering a snake, I was holding it up by the tail with the left hand, I come
down with a machete behind the head, and the head popped off the body, it caught me with
one thing on the finger.
You can barely see that little scar right across my thigh.
And this scar from here up to my elbow was surgery they had to do to open the arm up
so it didn't just literally split open on its own, because my arm swelled up as big
as what my thigh is now, and you could see the bone and the ligaments, and they had to
scrape a lot of dead meat out of there.
Our department found that there was a significant impact.
There would be regulations.
Yeah, the JCs, several of them have told me if we thought we were hurting the resource,
we would shut this down and come up with something else.
But there's no evidence whatsoever to indicate that.
If rattlesnakes are truly vicious, and not just typecast, it ought to show up when they
square off with each other.
Two male rattlers fighting over a female, now that should be a bloodthirsty spectacle.
It is, though, it's more like skinny guys arm-wrestling.
An adult female emerges from hibernation in the spring.
She may or may not be going to reproduce that year.
If she's not, what we see so far is that she's never visited by a male.
She comes out of hibernation, and she spends the entire active season looking for prey
in feeding.
If she's a female that's going to reproduce the following year, then this year she's going
to be mated.
And during the summer monsoon season from late July to early September, she will be
visited by as many as several males, and will probably mate with at least one of them.
During this intense mating period, of course, the males who are capable of mating every
year are spending a lot of their time and energy intensely searching for receptive females.
So whereas we see the females crawling slowly and moving from rat nest to rat nest, what
we see the males doing is making log movements, sometimes several hundred yards in a day,
apparently spending all their time searching for females.
Because there are fewer females receptive than males looking for receptive females,
we have a situation in which males are willing, so to speak, to fight over females.
And that engenders a situation where you have this combat behavior.
Two males will meet.
In our experience, it's usually in the vicinity of a female.
The males begin a wrestling match in which they rise up into the air, and each one appears
to try to push the other one's head against the ground.
Generally speaking, rattlesnakes are not affected by the venom of their own species.
Or perhaps a bite wouldn't even be an effective form of fighting.
The other thing is, though, that in general in animals we see what we call ritualization
of fighting, such that it usually or often doesn't lead to serious injury, but rather
as a contest of strength.
The animal that's dominated gives up at some point, won't fight anymore, and flees, and
is chased, in fact, sometimes by the other male.
The winning male seems to return to the female and resume courtship.
Maybe it's hard, especially in Texas, to imagine a scrap over a girl where the boys just dance
and nobody gets hurt.
That's because we tend to see what animals do in people terms, as if they felt the way
we do.
And that's one reason rattlers get typecast, human emotions.
But science has to steer clear of the emotion trap, even though comparisons sometimes jump
right out at them.
They mate with females that hibernate in the same ledge system.
This male number 26, who is the heaviest, healthiest, one could almost say studliest
male we've had, he just zips around this area.
I mean, in two days, he moved from way over there, hundreds of meters back here, spent
a little time over here and went back over there and found another female.
They're part of another local subpopulation of black-tailed rattlesnakes that generally
does not interbreed with this one, but occasionally you get these amazing males who make such
long movements that they trade some genes over there.
Genetic studies, there you go.
Anybody who sees snakes as DNA is going to be less tempted to conjure up strapping heroes
or slippery villains.
That's where science really makes nature hold still, under the microscope, but it still
has to start outdoors.
Well, there are three different species that live in these mountain ranges, the banded
rock rattlesnake, the twin-spotted rattlesnake, and then the ridge-nosed rattlesnake, which
is actually an endangered or threatened species.
So I'm looking at all three of those species.
Because I'm interested in finding out how different the species are in different mountain
ranges, I obtain DNA from different snakes, just like this one, by taking a small clip
from one of the belly scales, extracting DNA from that and then sequencing it for animals
from all the different mountain ranges.
And then I compare those sequences to see how different they are genetically.
What the DNA tells us is how closely different forms are related.
So it gives us a history of the species as a whole.
So when this species first moved into these sky islands, however long ago that was, they
began to differentiate because they're isolated on these different mountain tops.
And what the DNA allows us to do is to reconstruct that history and find out how these snakes
moved into the islands, which islands are more closely related to each other.
All right, away you go.
The other thing we found, especially for the ridge-nosed rattlesnake, is that the subspecific
denominations don't really match with what we would have expected in terms of genetic
differentiation.
Knowing what the differentiation is among subspecies, what the differentiation is among
sky islands, we can say something about what should be taken care of or protected.
In the coliseum itself, we are really dedicated to education about the western diamondback
rattlesnake.
We've got a research pit that we will weigh and measure insects, the rattlesnakes.
You take the probe and put it up underneath the little flap and bring it down.
If it goes in, it's a male, if it does not go in, it's a female.
This one went in, so this one's a male.
You turn them over, they'll straighten out, you usually don't like to try to pick them
up when they're curled up.
It's a little bit more dangerous that way.
We've got a milking pit where we do milk the snakes.
When we milk them, they have two venom sacs right behind each eye, and you squeeze those
to help them get the venom out.
That venom is used in research, whether it's cancer research or arthritis research.
You can never get all the venom out, but we get as much as we can.
Then we have safety demonstrations taking place all day long.
The book says that a western diamondback rattlesnake will strike approximately half the length
of his body.
We got some guys in here that hadn't read that book.
We don't really have any accurate records to tell how much money changes hands and how
it is an economic boost to our community.
That's enough for me.
But the money that's brought in here will turn over three to four times.
That's estimated in the millions of dollars that it means to Nolan County and the Sweetwater
area.
He's probably the most fascinated.
He wants to go look at them as much as he can.
I think he kind of likes them.
There are some roundups around the area that really try to sensationalize the rattlesnake.
Sleeping bag events where snakes are in sleeping bags and guys getting in the sleeping bags.
We don't do that.
We really discourage that because we're more dedicated to safety and education about the
western diamondback.
This is nice to see them in the pens because you can see them and hear them and everything
but you don't have to actually touch them unless you want to.
Based on the way people react to rattlesnakes, it appears they'd rather go through a life
on autopilot.
We don't usually want to worry about the dangers that the natural world poses.
In fact, if we'd actually learn a little bit about these animals and just maintain some
level of awareness of their presence, what little risk truly exists can be even further
reduced.
I haven't studied rattlesnake roundups myself so I don't have any direct knowledge of their
effects but what I've read suggests that although they're probably not affecting the persistence
of common species like western diamondbacks, that's a very common rattlesnake over much
of the southwestern United States including the areas where the roundups are held.
But it does seem to be the case that snakes don't get as big as they used to in those
areas and that snakes are not as common as they used to be in those areas and if I lived
in those areas I'd certainly be interested in what the consequences of that was in terms
of things like cotton rat populations and parasites that live on cotton rats and carry
diseases and so forth.
And I think probably the most impressive thing is that they persist at all.
If this was being done to some organism like a cotton tail or a squirrel or even a fox,
I don't think society would tolerate it.
On the other hand, if a bite from a cotton tail could end up in a scar like a tent flap,
we'd probably have bunny roundups to consider too.
But people in the snake bite culture are not impractical.
Even if they're not yet aware of everything that's good about rattlesnakes, they would
agree I think that when a rusty nail catches your attention, you don't pull it out without
checking first to see if it's holding something together.
Funding for this program has been provided by Asarco, Inc. and the Arizona Game and Fish
Heritage Fund.
Asarco, Inc., producing the metals we all need, respecting the environment we all value.
Asarco, a proud financial partner of public television for eight continuous years.
And by the Arizona Game and Fish Heritage Fund, conserving Arizona's diverse wildlife
resources.
To order Rattler on videocassette, call PBS Home Video at 1-800-828-4PBS or write to
the address on your screen.
This is PBS.