Reptile & Amphibian Forums

I understand the accepted explaination for snakes vibrating their tails to mimic rattlesnakes. I was wondering if maybe snakes started vibrating the tail first and rattlesnakes just improved on this. Does any evidence exist to point one way or the other?

Jim

You question is the right answer...non-venomous (and non-rattlesnake venomous) species are not mimicking rattlesnakes by vibrating their tail...after all, many species of snakes that are not even in the same hemisphere as rattlesnakes (being that they are only a new world snake) vibrate their tails, therefore mimicry is out of the question. Rattlesnakes just went a step further evolutionarily speaking than other snakes in that instead of simply rattling their tails on the ground, they developed a rattle to produce a much more distinct warning.

That just doesn't make sense, the reason that a Ratsnake is intimidating when rattling it's tail is because it sounds like something dangerous. Though it may be true that some species in different locales still exhibit this behavior as a means of defense, there is really no other logical explanation other than the fact that birds, people, and predators see this as a warning. Why else would they see it as a warning if the sound they were making was not linked to something deadly. The quesiton is interesting but the reverse doesn't add up. I'm anxious to hear what other people have to say. The fact that snakes exhibit this bahavior and live in areas where rattlesnakes do not, or never lived in these areas, may just be evidence of an evolutionary defense mechanism that has proven to work. How long do survival instincts last? This may be an instinct that has survived millions of years of evolution and migration. But to say that the rattlesnake is taking this warning to another level is actually saying the rattlesnake is doing the mimicry. That is more difficult to believe.

I don't believe it's mimicry, rattling tails by either venomous or non venomous is considered a defense posture.

Thought I'd weigh in on the subject...

To say that the rattlesnakes are "doing the mimicry" is certainly a big (and perhaps a bit misguided) evolutionary leap. The evolution of the rattle in Crotalids arises from a trait (as indicated in previous posts) that is rather commom in snakes (i.e. tail vibrating). What the rattle is, therefore, is a variation on this theme. In terms of adaptation, the evolution of the rattle may have made a defensive mechanism common to many snakes more efficient in detering predators. The trait is then passed on to their offspring. So by perhaps being able to produce a "louder" defensive sound in tail vibrating, the rattle itself provided a selective advantage.

So lets think of this subject in other terms. King cobras are renowned for their hissing, correct? Pituophis species also hiss...in fact have evolved an epiglottal keel. So is this a case of mimicry by bullsnakes? The answer is no. Hissing is a common and effective defensive behavior (and yes, behaviors are traits that can be passed on!). Pine, bull, and gophersnakes have taken this a step further and are really able to belt it out!

So, my thoughts are that traits like tail vibrating and hissing are common and effective defensive measures. As is the case with many traits (and at the heart of the theory of evolution), some species have (through various mechanisms...mutations, etc.) adapted more "extreme" examples of these traits, and have consequently passed it on because it was more effective in deterring predators.

Anyways...interesting topic, in my opinion!

..more of a physiological response to being scared or feeling threatened. Its no different than when people get nervous and start tapping their fingers on a desk or their toes to calm themselves down. Snakes don't have much choice other than vibrating their tails. Rattlesnakes just took the concept and improved on it...possibly because of the risk of being trampled by larger animals that had poor hearing or because of living in a grassland where few dry leaves amplified the sound.

MCH

I don't think it really stops at snakes. Look at other tailed animals, their demeanor can normally be seen by what their tail is doing. Our cats will actually vibrate their tails when they are threatened and, though they were rescues and had been on the streets prior, I doubt it was anything to do with them witnessing the behavior with rattlesnakes. Same with some dogs and I have even seen ferrets do it too.
-----
Bryan, Atlanta GA

1-0-0 Rescued Ball Python - Apep
0-1-0 Rescued Mountain Horned Dragon - Ki
0-0-1 Rescued Aggressive Bearded Dragon - Zeus
0-0-1 Rescued Non-Alpha Green Iguana - Bud
1-1-0 Rescued Rats... no wait... ROTTEN Little Cats - Ra, Bastet
0-0-1 Rescued Dieting Panda Hamster - Mr. Fluffy
0-1-0 Rescued Little Angelic Kitten - Isis
1-0-0 Horse... whoops... BIG Golden Retriever - Jake
0-1-0 Wife
2-0-0 Kids

..it's response that many animals exhibit.

We all know what a growl is regardless of what the animal is or what the colors red and orange indicate,or what eye contact means. There is an universally understood basic language that exists between species on the earth, the rapid tail movement may be one of them. These expressions are universal because they existed long before the different species and creatures that use them today did and there meaning was passed down as we evolved.

I agree with what everyone else has said about the rattlesnake just doing a better job, rather than mimicry in either direction. There's probably no way to prove this, but that was the conclusion I came to pretty quickly once I gave it a little thought.

I would also like to throw out a couple of other ideas for discussion as to why non-venomous snakes "rattle".

1) Maybe it's more of a distaction than a warning. Lots of snakes that don't really "rattle" will hide their heads and wiggle their tails so that a predator will go after their tail which is less vulnerable. "Rattling" could have evolved as simply a more effective version of this.
2) Even many nonvenomous snakes can inflict a painful bite, and so a distintive warning associated with that bite could still deter at least some predators even without venom. This seems more likely to be the current use in some snakes since they may gape, hiss, inflate their necks and/or strike while rattling.
3) Dr. Fry's research suggests at least the possibility that in the evolutionary past a much larger percentage of snakes may have been venomous which would make a "rattling equals danger" warning more plausable, and maybe it's carried through even though the venom hasn't.
4) All of the above.

Thank you for the responses.
The consensus would seem to be that without a prior tendency to vibrate the tail, the rattle would not evolve.
Now I am interested in the Dr. Fry perspective. The original thought would be:
1 vibrate tail (equals nasty bite)
2 venom
3 rattle
New school (according to Dr. Fry) would be:
1 venom (which has evolved away in some species)
2 vibrate tail (which many species still do)
3 rattle
Which came first, the venom or the warning?

PS I respect Dr. Fry but his reseach motivates the question.

My understanding of the origins of a rattlesnakes rattle is not to warn any animal or human that "I'm dangerous!", but a warning system to not get trampled on. Rattlesnake evolution took place during a time when giant mammals roamed North america-The Mega Fauna. You had countless numbers of bison(at one point in the millions), antelope, giant deer, 2 species of elephants, ground sloths(some standing 14' high), lions, tigers, saber cats, bears, wolves. all much larger, and some more numerous, than there present day counterparts. A rattlesnake wouldn't stand a chance in the middle of a large herd of bison. But if it shook its rattle it is letting the bison know "Hey! I'm here!" and hopefully the bison goes the other direction. Cause a rattlesnake bite will not kill a 2 ton bison. It may mess it up for a few days but not kill it. Same for horses. At one time there were thousands of horses on this continent til they went extinct. And it wasn't til Spanish conquorers brought them for transpartaion that they were introduced back into this country. As far as tail rattling in many other species, I think it is an ancient form of warning. But a snake isn't going to make much noise in a grassy field with moos, grunts and other calls with only its tail rustling on the ground. To be heard it would need something loud for audible animals to hear clearly. Now yes I've caught many snakes rattling their tail in leaves and it does make a very loud noise, but out in the plains where alot of rattlers are, there aren't alot of trees. I think that could be a whole other topic on rattlesnake origins and historilogical dispersion throughout North America. Now all this is just my opinion on this subject. By all means I could be totally wrong, totally right, or 50/50.
-----
"I am all that is Divine, I am all that is Evil.
I am the one who brings forth Death,
On the wings of a Weevil." JSKII

....I tend to prefer the trampling avoidance scenario myself, in part due to the rattleless snattlerakes in the gulf of Ca.... But then this scenario begs...why only in the new world? The african plains have had great herds of ungulates for at least as long...why no rattling vipers or elapids there??? & scale rubbing is a poor second...

Ophidian defense strategies are most interesting to me, after seeing a number of gopher snakes dispatched by critters ranging from kingsnakes to redtail hawks to coyotes & their elaborate huffing & striking being utterly useless....they might just as well roll up like a rubber boa for all the good it did them...how/why do these mechanisms evolve?

I intend to examine regal ringnecks aposmatic displays in this regard...do they disuade color sensitive predators? Thus far it appears to me...ophidian predators even the generalists, seem to just charge in & dispatch the serpent w/ ease, & the snake's only chance is to go undetected via crypsis.

We must be careful of the dogma; that all repetitive behavioral observations have a causal=evolutionary mechanism...it may not be so, or the value of the behavior may be yet undetected by us???

Saludos / RxR

Rattlesnakes are pit vipers, and they are the most recent snakes to evolve. The snakes that vibrate their tales like a rattlesnake that I know of are colubrids, or common snakes. Some of the colubrids that do this are rat snakes, milk snakes, and king snakes. These snakes, like all other colubrids evolved before the vipers. Therefore, snakes were already vibrating their tales before rattlesnakes came about.

I cannot think (off hand) of any old world snake that vibrates it's tail. All of the one's mentioned have been new world snakes.
Randal Berry

I agree with Physignathus. It's no coincidence that rattlers only evolved in such a large plains area occupied by large grazers. The ones that didn't have rattles were soon being picked out of bison hooves. All it took was a primitive rattle with some volume, and that animal would be avoided by most land animals. Obviously a stampede wouldn't be affected, but grazing animals would soon associate that sound with another of their herd falling over dead.

Yes, there are large savannah areas in Africa, but not the size of the great plains. Also, the same evolutionary path does not HAVE to be followed in other areas, although it can happen.
-----
1.1 Blackheaded pythons
1.1 Woma (Juvie female)
2.1 Aussie Olives
1.1 Timors
1.0 Angolan Juvie
1.1 Savu
1.1 Juvie Bloods
1.1 Juvie Balls
1.1 IJ Carpets
1.1 Coastal Carpets
1.2 Macklotts
1.1 Papuan Olives
0.1 Jungle Carpet
2.2 Scrubs (on breeding loan)
1.0 Jungle/Diamond cross
0.1 child, CB
0.1 wife, WC

This is probably worth it's own thread, but I personally am not convinced that rattles evolved as a great plains/anti-trampling device. My reason is that most places rattle snakes live are NOT great plains. They are in mountains, deserts, jungles, pine forests. Most of these places have only the remotest chance for an individual to be stepped on. The defensive device remains on ALL BUT ONE small insular population who may have lost rattles due to their bush climbing/bird hunting strategy.

I don't know how long Rattlesnakes have been around, but the past few hundred thousand years, ice-age periods have waxed and waned. The set of large animals has changed dramatically, both predator and prey. Deserts, forests, grasslands have increased and receded. Yet through all these changes, rattlesnakes keep their rattles.

Think about it, before the last ice-age, there were Large Elephants, Rhinos, Giant Sloths, Camels, Giant Armadillos. The North American view looked a LOT like our view of Africa. African snakes seem to be surviving just fine with their own set of elephants, rhinos, camels, and other large hooved animals. They aren't under threat of going extinct because of the absense of loud audible warning.

I better be careful or I might start on the topic of how I think the theory that Milk Snakes are mimicking Coral snakes is wrong too.

Doug T

>>I agree with Physignathus. It's no coincidence that rattlers only evolved in such a large plains area occupied by large grazers. The ones that didn't have rattles were soon being picked out of bison hooves.
>>
>>Yes, there are large savannah areas in Africa, but not the size of the great plains. Also, the same evolutionary path does not HAVE to be followed in other areas, although it can happen.

Yes, Africa does have its own LARGE fauna but nothing compared to what roamed this continent during the evolutionary history of rattlesnakes. And also to my knowledge from my interests in paleontology no one has found any "mega fauna" mammals in africa. You compare an African bull elephant to a bull Woolly Mammoth or a bull Columbian Mastodon and the African bull will look small. As far as hooved mammals they can gain access to remote places that rattlesnakes are at. Look at the mountain goat, pronghorn sheep. Now here is a whole other topic-Where did rattlesnakes originate on this continent? Some species of rattlesnakes have a large population range and may cover from the plains upto some of the highest elevations in the rockies or from forest floors and valleys upto the appalachians. And I know some species ranges overlap each others. And yes I know this continent has gone through some major changes in the last 2-3 million yrs(as far as rattlesnakes linneage goes back, to my knowledge)and animals have come and gone. And during glaciations most of the land and high elevations were locked under ice thus less land to disperse causing a sort of over-crowding. Africa never was glaciated and therefore never became too cold like it did here. And really it wasn't an artic freeze here during glaciation it was just cooler with drier conditions from the cold air coming down off the glaciers. I better quit before I go too deep into this, LOL.
-----
"I am all that is Divine, I am all that is Evil.
I am the one who brings forth Death,
On the wings of a Weevil." JSKII

"I better be careful or I might start on the topic of how I think the theory that Milk Snakes are mimicking Coral snakes is wrong too. "

To phrase it that way, I would agree. Saying that one snake is mimicing another would be placing a personification upon them. Are you of the mindset that it was all an affect of the predation results? A "passive" mimicry if you will....
-----
Tom
TCJ Herps
"The more people I meet, the more I like my snakes"

Which came first, the split off of the venomous adaptation, or the rattle? Knowing which came first might help confuse everyone even more.

After reading all the arguments, some kind of childish, Im gonna side with the "grazer anti-trample warning mechanism" considering which animals are prone to the behavior and where they come from mostly.
Since snakes are solitary animals for the most part of their lives, I would doubt that any one type of snake developed a behavior to try to be like another species. If that were true, that would be an indication of a learned behavior, and their brains arent that complex. On the same token, milk snakes that end up looking like coral snakes were picked out by the hand of evolution, rather than as a result of wanting to look like a coral snake or trying to mimic another species because it "understands" that this was a good thing to do.
-----
Tom
TCJ Herps
"The more people I meet, the more I like my snakes"

"On the same token, milk snakes that end up looking like coral snakes were picked out by the hand of evolution, rather than as a result of wanting to look like a coral snake or trying to mimic another species because it "understands" that this was a good thing to do."

The hand of evolution? Please explain.

I think nature "designed" milk/king snakes as mimics to Coral's or the other the way around, as a "visual defense" to other animals, i.e.,"bright" colors to warn other animals to leave it alone.

>>I think nature "designed" milk/king snakes as mimics to Coral's or the other the way around, as a "visual defense" to other animals, i.e.,"bright" colors to warn other animals to leave it alone.

There are two types of mimicry going on there: Mullerian and Batesian (spelling?). Both CAN be at work - they aren't mutually exclusive.

KJ

>>"On the same token, milk snakes that end up looking like coral snakes were picked out by the hand of evolution, rather than as a result of wanting to look like a coral snake or trying to mimic another species because it "understands" that this was a good thing to do."
>>
>>The hand of evolution? Please explain.

Maybe not the best choice of words. Don't take it too literally. I think it was just another way of saying "natural seletion".

>>I think nature "designed" milk/king snakes as mimics to Coral's or the other the way around, as a "visual defense" to other animals, i.e.,"bright" colors to warn other animals to leave it alone.

Maybe I'm taking YOUR words too literally here, but unless you're working with some sort of Wiccan world view, using "nature" and "design" in the same sentence seems to suggest a fundamental misunderstanding of evolution.

Unless there's some component of evolution that no one has been able to explain of demonstrate in the last 150 years then milk/king snakes would most likely have evolved red/yellow/black banding in one of a couple of ways that I can think of:
1) A random mutation leading to this color pattern and those with that pattern were more successful than their competetors as a result:
a) because predators mistook them for corals (the mimicry theory) or
b) because predators were simply startled or confused by the bright colors
2) A gene/genes for this pattern evolved for what ever reason in the ancient past but were later surpressed or lost in most lines, but survived in some milk/king snakes as well as corals.

At frist glance 1) would seem much more likely because because of the banding order, but considering that there are corals with the same colors in different orders it could simply be that there is one gene or set of genes for the colors and another set for the order.

Either way, it's very unlikely that learning or any decision whatsoever on the part of the snake had any effect on it's evolution (although learning by its predators might). When most people use the word "mimicry" in this context the are using it rather loosely. They just mean that something works because it happens to look or act like something else, not that it is actually TRYING to look or act like something else.

Larry, I assure you I'm not taking a Wiccan standpoint! LOL! This whole thread could take a turn to convergent evolution and how that has affected new world snakes, which BTW I thought how this thread started.
However, we can agree to disagree here.
But your quote,

"When most people use the word "mimicry" in this context the are using it rather loosely. They just mean that something works because it happens to look or act like something else, not that it is actually TRYING to look or act like something else."

I have to disagree here, what about Hognose snake defense? They intentionally try to look OR act like something else when startled. There are several snakes that try to make themselves bigger as a defense mechanism, and color/banding/genetics has nothing to do with it. They are mimicking something that they are not, that is what mimicry is.

This should open up a big can of worms! LOL!

I've found this thread to be very interesting and enlightening. I've often wondered why snakes rattle and hiss, considering that they don't have ears and are deaf. I know they can feel vibrations such as heavy foot steps, etc. But I guess they can hiss and rattle without even knowing they are making the sound. Through natural selection it is a behavior that exists simply because it works, not necessarily because they understand or are even aware of the sounds.
-----
1.1 Jungle Carpet Python
1.1 Ball Python
1.1 Corn Snake
0.1 Gray band Kingsnake
0.1 Desert Kingsnake
0.1 Pueblan Milksnake
1.0 Bullsnake
1.0 Rhodesian Ridgeback (Hondo)
0.1 Spouse (WC)
0.0.8 hatchling ball pythons

>>I have to disagree here, what about Hognose snake defense? They intentionally try to look OR act like something else when startled. There are several snakes that try to make themselves bigger as a defense mechanism...

>>This should open up a big can of worms! LOL!

One order of worms, coming up.

No, no, no, a thousand times no. Hognose snakes have no idea that they look or sound like somehting else or even that they look scary. I assure you if you take a hognose egg and put in a box until it hatches, when you open the box it will very likely puff up and hiss. It has evolved that preprogrammed response to perceived danger. It's possible/probable that that trait was beneficial and therefore passed on because it fooled predators, but it has nothing to do with any conscious calculation by the snake.

Larry,
I see you finally get my point. That is exactly what I was saying.

Randal

>>I see you finally get my point. That is exactly what I was saying.

You're just trying to make my head explode aren't you?

This stuff makes me wonder about the coral snake/tricolor snake connection. I always thought the tricolors where mimicing the deadly corals. The more I learn the more it seems that as potent as coral snake venom is, it is not functionally defensive (maybe more so in the past, but now conserved as most venomous consider this commodity "valuable"?). So why the mimicry, which could only serve to scare away the prey which the venom is used on (which probably only see in black and white anyway)? I guess a related question would be what is the proportion of predators/prey and color vision/BW vision that causes any color mimicry to make sense anyway. Is any other venomous snake as mimiced (if that is what is is) as the coral snake which is not aggressive anyway?
Thanks to you all for indulging me on this.
Jim

Yea I learned a great deal also from this subject and I'm very happy for that. I really don't have any opinion on this whole thing, but I do think its nature. Just look at the animal kingdom besides snakes, bugs mimic all the time and take it to new highs, why not snakes? Corns also vibrate there tails by the way.... Mine does it all the time. And I also want to side with the trampling theory because it makes a little more sense than the other arguments. But I don't think a specific snake says to itself "hey look what those guys are doing, let me do it times 10", LoL that would be hilarious, so that kind of debunks the whole theory of them understanding that it works for them so it might work for me theory but it doesn't totally disprove it.

As LarryF hit on the nose, I was referring to natural selection. Over time, the animals which proved to have developed some kind of mechanism survived better and reproduced more often then animals without the mechanism which evenutally died off.

My take on the coral/milk mimicry thing is that predators learned not to mess with the snakes which had a certain coloration to them, and it just so happened that another kind of snake was taking on the same coloration, so it was left alone. This is just a broad explanation of a process that would have taken hundreds of thousands of years to come to fruition. Not a happening that could have been recorded over a weekend. Heheee
-----
Tom
TCJ Herps
"The more people I meet, the more I like my snakes"

I have been doing a lot of research lately on rattlesnake evolution. The tail rattling is common in areas where pit vipers live, which is why Asian and American snake rattle tails, but European and African ones don't. The rattlesnake tail is believed to be an amplification of this behavior.

Contrary to common belief, rattlesnakes did not evolve on the plains of North America and thier rattle wasn't to warn of large grazing animals. It is now thought that they evolved in the mountains of Mexico. The reason why is harder to come by. It is either to warn off small carnivores like the coati or to protect the tip of the tail. The 2 tail protection theories are based on that the rattling would have occured in rocky areas where small stones and pebbles could damage the tail. Also many of the rattleless tail shakers commonly rattle thier tail against dried leave to amplify the sound. Since thier are no dried leaves in these areas, the rattlesnake might have developed something else (the rattle) to make themselves heard. The other thought is that since the tail was used as a caudal lure, the keratin links (rattle) protected the tip of the tail incase it got bit.

Mind you, this is not a fact, just a few of the theories I've picked up in my research. This has gotten me very interested in this "behavior evolution".

"It is now thought that they evolved in the mountains of Mexico. The reason why is harder to come by."

Sound carries further up there???? LOL
-----
1.1 Blackheaded pythons
1.1 Woma (Juvie female)
2.1 Aussie Olives
1.1 Timors
1.0 Angolan Juvie
1.1 Savu
1.1 Juvie Bloods
1.1 Juvie Balls
1.1 IJ Carpets
1.1 Coastal Carpets
1.2 Macklotts
1.1 Papuan Olives
0.1 Jungle Carpet
2.2 Scrubs (on breeding loan)
1.0 Jungle/Diamond cross
0.1 child, CB
0.1 wife, WC

I did not say that rattlesnakes evolved on the plains. I stated that the rattle may have evolved from trying to warn large hooved mammals. Big difference. As far as origins of the rattlesnake pit vipers, that I don't know. Origins in Mexico? Any fossil evidence to prove this?
-----
"I am all that is Divine, I am all that is Evil.
I am the one who brings forth Death,
On the wings of a Weevil." JSKII

"I did not say that rattlesnakes evolved on the plains."

lol..I'm the one that started that one. It's a viable theory. Heck, there are plenty of plants slowly dying off because the large grazers no longer eat the seed pods. (what DOES eat an Osage Orange nowadays in one bite?) I doubt that most mammoths had problems w/poisonous snakes because of the size...much like an elephant. Large herds of herbivores that startle easily would be my best guess.

Anyway, that's my story...and I'm sticking to it
-----
1.1 Blackheaded pythons
1.1 Woma (Juvie female)
2.1 Aussie Olives
1.1 Timors
1.0 Angolan Juvie
1.1 Savu
1.1 Juvie Bloods
1.1 Juvie Balls
1.1 IJ Carpets
1.1 Coastal Carpets
1.2 Macklotts
1.1 Papuan Olives
1.0 Jungle Carpet
2.2 Scrubs (on breeding loan)
0.1 Jungle/Diamond cross
0.1 child, CB
0.1 wife, WC

As a matter of fact, there is fossil evidence of rattlesnakes in Mexico. There is no fossil evidence of rattlesnakes in the great plains.

Someone earlier also brought up the fact that there is a much higher number of species in Mexico than there is in the US. In fact, all rattlers except 3 are found in Mexico.

"Someone earlier also brought up the fact that there is a much higher number of species in Mexico than there is in the US. In fact, all rattlers except 3 are found in Mexico."

Take this with the humor intended....but were the bison stopping the rattlers at the border? How many rattlers crossed the Rio?
-----
1.1 Blackheaded pythons
1.1 Woma (Juvie female)
2.1 Aussie Olives
1.1 Timors
1.0 Angolan Juvie
1.1 Savu
1.1 Juvie Bloods
1.1 Juvie Balls
1.1 IJ Carpets
1.1 Coastal Carpets
1.2 Macklotts
1.1 Papuan Olives
1.0 Jungle Carpet
2.2 Scrubs (on breeding loan)
0.1 Jungle/Diamond cross
0.1 child, CB
0.1 wife, WC