Rattlesnakes evolving?

[I-KandyReptiles]

Anyone else read this? It got mentioned on a radio station here, so I googled it and found this article:

http://www.npr.org/templates/story/s...ryId=216924322

Thoughts?

[Tribal]

I am going on a dove hunt in Cotulla TX and there is a dense population there so I hope it is not true lol. They are not scary when you know they are there but a quiet one gives me an uneasy feeling.

[Mephibosheth1]

Could definitely see it happening

This isn't "evolution" in terms of "they're gonna be walking up trees" or flying though. Rattler still a rattler genetically, even if their tails are atrophied....

[reptileexperts]

It's called selection of a trait that keeps getting inherited because its beneficial to the organism - "On the origin of species - by means of natural selection . . . " natural selection is when a genetic trait randomly pops up and its favored. This leads to population shifts. Of course, this does not mean that it will always be the case, populations can shift back, and in this case if there is anything that makes the atrophied tail a weakness, it willl be exploited heavily in enough time.

Is it evolving? eh. . . one snake evolved a mutation and it just happeend to stick.

Common thought - in Texas, it has been noted as well that Western Diamondbacks will not rattle unless you are within a certain distance of them. In fact, if they believed that they have not been seen they may simply retreat. Only when cornered wiill the display of danger come out.

Cheers

[sorraia]

Natural selection... those animals best adapted to their environment are the ones most likely to survive and reproduce. Those who reproduce pass on their genes, both for morphology and behavior. Therefore... if rattlesnakes who make noise are more easily detected and more likely to be killed, they are also less likely to survive and reproduce. If they are less likely to survive and reproduce, then rattling snakes become less and less common. The real question becomes, is this true, or is data just lacking?

Interestingly enough... there actually is a species of rattlesnake that does not possess a rattle. A coworker of mine used to work on the island where these snakes occur. I first learned about them from her.
Santa Catalina Island Rattlesnake: http://www.sdnhm.org/archive/fieldgu.../crot-cat.html

[Raven01]

I saw something on the rattlers in an entire county not rattling. There was an old guy that hunts rattlesnakes as often as he can, usually by sound in probable locations. The theory is his hunting pressure has left only the quieter snakes to pass on their genes so, over the last few decades snake in that area have become quiet rattlesnakes.
His fear of what he doesn't understand is in effect endangering more people as the snakes do not try to warn you off but, instead are more likely to freeze then strike if you seem to be posing a threat.

[Diamond Serpents]

Pretty cool read, I really don't think its a issue if they lost the rattle. You can't hear other venomous snakes warning you (besides maybe a hiss). Don't forget rattle snakes have body language when they're going to strike just like any other snake. The rattle is just a sound warning so I really don't see this effecting anything but definitely really neat how some are getting quieter.

I mean we have rattlesnakes here in PA in our mountains which is 45 min away. But for example I live in the country and I have never seen one in any of my woods in 26 years of playing in them growing up.They just stay up in the mountains and survive our cold winters in large snake pits. These snakes are very interesting indeed of how they have evolved and live in general.

[wienkeg]

Yep, rattlesnakes evolving to deal with humans. Rattlesnake with no rattle = doesn't get killed by some idiot who hates snakes. Rattlesnake with rattle = gets killed by some idiot who hates snakes.

Rattlesnake with no rattle gets to pass it's genes on, just like the ball pythons with cool genes get to pass them on.

[sorraia]

Here's an interesting blog post. It's not about the article posted in this thread, but about an email going around stating that hogs in Texas eat rattlesnakes that rattle and so the Texas rattlesnakes aren't rattling any more.

http://www.livingalongsidewildlife.c...s-because.html


I already gave a reply, but wanted to expand. I'm not fully convinced rattlesnakes are rattling less because of people. If rattlesnakes are tending toward rattling less, I believe it goes beyond just people. I personally have a feeling part of this may be a case of people not realizing how often rattlesnakes do or don't rattle. I can only speak for my personal observations and experiences, but in that experience and observation, rattlesnakes only rattle as a last ditch effort to scare off a potential threat. They don't rattle unless that threat comes within a certain distance. In my experience, that distance is about 3 feet. The snake also needs to feel exposed, and be warm enough to react. If it's a cool morning, the snake may just sit tight, perhaps too cold to move. Rattlesnakes aren't especially vibrantly colored (or at least not the ones I've seen), they rely on their camouflage to protect themselves much more than they rely on their rattle. Biting tends to be the last ditch effort when all else has failed. Neonates don't even have rattles to make noise with, so in a way they are potentially more dangerous than the adults who do rattle.

As nice as the rattle is for a warning, it isn't something any of us should rely on. Rattlesnakes don't rattle every time. My dad grew up in an area where there were lots of rattlesnakes. I'm a biologist now and I venture into rattlesnake areas as part of my job. My dad taught me the most dangerous rattlesnake is the one you don't hear. If you are going out in an area where there are venomous snakes, you should always keep your eyes open, not just your ears. I once watched a coworker almost step on a rattlesnake, early one morning while the snake was still trying to warm up. My coworker didn't even see the snake, even though it was very obvious to me, but I also have a tendency to look where I'm putting my feet.

[djansen]

I go looking for them here in AZ and have only had one not rattle even though I was almost on top of him, the others were quite inclined to let me know they were there.