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this kept me up for a few minutes last night. did rattlesnakes evolve the rattle to enhance the rattling that so many rattle-less snakes do? (king, corn, bullsnakes etc.)OR, do the rattle-less snakes mimic rattlesnake rattles?
just curious, really
joe

Well I'll give it a try -- rattlesnakes evolved largely in territory and times when there were large herds of hooved animals - primarily buffalo -- which would likely have stepped on them in a terminal fashion during migrations. Hence it makes sense that something to warm the advancing critters that there was a venomous creature underfoot would have been an evolutionary advantage. I would think the tail shaking behavior of some other snakes would have followed as an evolutionaty adaption that says "I'm not really a rattler, but I mimic one pretty well, so be wise and leave me the heck alone, sicne you can't really be sure." Much like insect mimicry -- the walking stick would have evolved after the stick for obvious reasons.

so, in short, the rattle came first, and the colubrids are mimicking the rattlesnakes behavior. thank you. makes you wonder why no african snakes evolved rattles, when there are many large herding mammals over there.

>>makes you wonder why no african snakes evolved rattles, when there are many large herding mammals over there.

Regardless of the presence of large animals, this is exactly why I disagree. There are plenty of African snakes that "rattle" (I'm pretty sure I've seen mambas do it). Asian ratsnakes rattle as do Australian taipans. As far as we know, there have never been rattlesnakes anywhere on those continents.

If you pay attention, I think you'll find that wild caught specimens of a majority of species "rattle".

There's probably no way to prove it either way, but I'm convinced that "rattling" evolved long before the rattlesnakes, maybe even before snakes. I think I even remember seeing iguanas and monitors "rattle".

I think the rattlesnake's rattle evolved simply as a better way, probably as described in a post below.
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What goes up must come down...unless it exceeds escape velocity.

I agree that colubrids probably developed the rattling behavior first. I have seen a fair number of snakes that rattle that have never had rattlesnakes in their natural range that rattle. Rattlesnakes may have just taken this already fairly effective warning to animals and just made it more effective. But my opinion is worth no more than anyone elses.

Mike

noone knows-- God gave them rattles?
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2 tham radix
1 Chicago Tham s. semifasciatus
2 elaphe vulpina
1 gray tiger sallie
4 Aphonopelma hentzi
2 G rosea
1 Haplo minax

"The evolution of the rattle is something of a mystery. There are no snakes with intermediate stages - they either have a rattle or they don't. Many other snakes, though, vibrate their tails if they are disturbed, and if they happen to be resting among dead leaves or loose pebbles, a rustling or a rattling sound is the result. The first step towards the evolution of a rattle could have been taken by a snake that vibrated its tail which had, by chance a deformed tip, causing a biuldup of shed epidermis."

---- Chris Mattison's the Encycloedia of snakes

Although no definate, it does offer a theory of the snake's rattle.

Snake mimicry is an interesting topic.

Often times when people see 2 species exhibit similar behavior they automatically jump to the conclusion that the "less dangerous" animal is mimicking the "more dangerous" animal. As others have mentioned many snakes of many taxa shake their tails. It is probably just by chance that rattlesnakes enhanced this behavior. The evolution of the rattle itself is still not greatly understood. However, I do believe it is just an "enhancement" of an already existing snake behavior. I think about the only genus that comes to mind that I can say that I've tried to observe "rattling" in that I haven't seen it would be Nerodia. While Nerodia musk, thrash their entire body, bite, and otherwise act pleasurably, I've neve seen one "rattle" its tail. Why? I dunno.

Another thought that comes to mind is often times people will see a north american hognose flatten out and they say that "it is hooding up to look like a cobra so that you think it is dangerous." This is very misleading. The 2 animals share a common behavior for defense. One of the animals just happens to be venomous. This behavior is also seen in other venomous ane nonvenomous species. The hognose is no more mimicking a cobra than the cobra is mimicking a hognose.

As to why a rattle hasn't evolved on other continents a better question is probably why did it evolve in the Americas. Random chance. I would venture that on average a lot of your African ground dwelling species have adapted warning methods to avoid being trampled. The large vipers of Africa are quite good at hissing and making their presence known. Perhaps they just took a different path to accomplish the same purpose that the rattle serves in the Americas, and happened to do so by random chance.

And to really open up a can of worms, look at coral snake mimicry and whether it is or not

I think Nerodia or Natrix wouldn't rattle their tail, because they are often found in water.
Rattlings one's tail in water would be very effective as a defensive posture. But, hey, what the hell do I know? LOL!

Randal

It sure seems like I remember my adult, wild-caught Nerodia fasciata rattling, but it's possible I'm confused.
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What goes up must come down...unless it exceeds escape velocity.

It's just my opinion that the tail shake came first, and rattlesnakes ended up with a device on the end to help enhance the rattling of the tail. I base this only on the other point I want to make here....

It's crucial that you keep in mind that evolution isnt the result of a conscious effort on a species part. An animal cant decide to evolve in a certain way. It either has the genes present, or it doesnt. Slight accidental differences are the root factor here, or a misfire of a Hock gene**. If the genes are present, and they get expressed, then that's when the change gets made. So, I think over time, snakes that shook their tails were less likely to get trampled or messed with. This behavior got passed on as part of instinct, like the same instinct that drives animals to eat when they're hungry. Over more time, the American species developed extra stuff on the tails that enhances the sound. Maybe it started as just a more blunt tail because more meat at the end creates more impact on the leaves or whatever. Then the meaty end developed a loose scale over it's tip, which happened to make a little rattling noise, and this was more successful than no noise at all, and thousands of generations later, more and more buttons started to not fall off during a shed.

I think, for a ratsnake to "try" and imitate a rattlesnake to keep it from getting molested sounds a bit wrong to me. A rat snake doesn't know how much better equipped rattlesnakes are

It's also difficult for some people to truly wrap their heads around how long this kind of thing takes to happen.

**Hock genes are like "boss" genes which have some control over groups of other genes. They provide general sets of instructions for more specific tasked genes. Recently, scientists manipulated a hock gene in a frog to grow a fifth leg where it's eye or ear should have gone. This is a drastic example, but given random chance, every once in a while a minor change will happen which doesnt negatively affect the ability of an animal to survive. Sometimes it's beneficial.

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Tom

"The more people I meet, the more I like my snakes"

>>I think, for a ratsnake to "try" and imitate a rattlesnake to keep it from getting molested sounds a bit wrong to me. A rat snake doesn't know how much better equipped rattlesnakes are

However, it doesn't really matter whether they know why it works, or even know that they are doing it for that matter. If rattlesnakes existed first, and a ratsnake randomly mutated to have a tail-shaking behavior and other animals mistook it for a rattlesnake, that snake's genes would be more likely to be passed on.

(But I don't think that's how it happened...probably...)
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What goes up must come down...unless it exceeds escape velocity.

Right, I agree. I just wanted to be clear that it's not conscious effort by the animal as a "learned by example" situation from another species.
It's all very interesting.
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Tom

"The more people I meet, the more I like my snakes"

What about the fact that some species of Old World Pythons and Boids use the tail as a diversionary tactic from the head? Have other snakes not evolved to use the tail the same way? I'm sure the sound of a rattle would aid in the attraction to the tail as opposed to other end used for eating.

Just another thought.

Nate

I have witnessed my Madagascar Ground Boa "Rattle". Sure we could call it caudal luring, but it wiggled it's tail when it was excited. I've often heard the thought that the rattle evolved to keep from being trampled by large hooved animals, but it just as easily could have been to scare away predators in rocky terrain.

As for mimicking of coral snakes....There are tricolored snakes even in WA state where I live. There aren't coral snakes within a 1000 miles or more from here. Tricolored snakes aren't mimicking coral snakes. They've evolved a color scheme that disappears when they move. When not in motion they have 3 colors. When they move, they are black. Try it yourself

Doug T

Here's one of those Washington Tri-colors.

Regarding the old world snakes I was refering to Charina bottae.

N/P
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http://www.simply-sober.com/him.html

http://simply-sober.com/blog1/

The egg came first. The cleidoic egg was in existence before chickens evolved, as they inherited this trait from their ancestor species. Therefore the egg came first.

Simple.

Whoa! Hold on there! The chicken came first!
The chicken had to lay the egg so we could go get Egg McMuffins at McDonalds. Whats wrong with you?
LOL!

What about the mc chicken
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http://www.simply-sober.com/him.html

http://simply-sober.com/blog1/

No sir, the chicken came first!
And we have Col. Sanders to thank for that.

That snake certainly isn't mimicking any coral snake.

Nice catch!

Doug T

>>Here's one of those Washington Tri-colors.
>>
>>Regarding the old world snakes I was refering to Charina bottae.

I've only seen Coral snakes at the zoo but I have videos of thier defence displays and I have to say Zonata and alot of the other Tri-color snakes do the same jerky, spazzing, looping movement IMO.

Nate