|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by FSB on February 6, 2010
|
Mail this to a friend!
|
|
I have searched but can't seem to find any further information on the web about the study by Rich Legere and Jim Ball. Perhaps it is still underway or has not been published. Marty seemed to have some reservations about it - he says they were comparing rattle-segment length and snakes from sparsely populated areas with snakes from areas with more human activity. My original query was just to find out whether or not such a study exists, without getting into the validity of the idea one way or another, but I'm glad to see the debate about it here. It's an idea that has been kicked around for some time by many people who work in the field, including Joe Slowinski. I started wondering about it over 3 decades ago when I started observing and collecting rattlesnakes in SW Virginia, where they had long been persecuted, and noticed how few of them ever sounded off, even while being hooked. If such a trait has begun to assert itself [and rattlesnakes have definitely been persecuted by humans for enough generations to have an effect], I don't think it would have to be a "knowing gene" or a conscious decision on the part of the snakes to not use their rattles. Much as I like them, I can't credit them with having the intelligence to associate the use of their rattles with getting themselves whacked. I do think that there is a natural range of temperament expressed in each generation that runs from excitable snakes that sound off at the slightest disturbance to quiet ones that are more prone to lie still and rely on their cryptic coloration. It makes sense that the snakes with calmer temperaments will be more likely, in the presence of humans, to survive, reproduce and pass their quieter temperaments along to at least some percentage of their progeny, while snakes that are quick to rattle will be selected for decapitation by loggers, hikers, farmers, etc. who otherwise wouldn't have noticed them. The idea does warrant further investigation.
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by Cro on February 6, 2010
|
Mail this to a friend!
|
Fred, this is a very interesting topic.
I hope you got the Email that I sent in reply concerning this topic, my computer was acting up that day.
As Charles has stated, Natural Selection can come into play.
If we have a population of rattlesnakes that live close to humans, and there are some in the bunch that are more excitable, and rattle when someone approaches too close, it is more likely that those snakes will be killed by humans right after they sound off and draw attention to themselves. And, it is even more likely that sounding off could cause a predator like a wild hog,(that kill and eat rattlesnakes), to locate that snake and use it for a meal.
On the other hand, if there are snakes in that same population that are less excitable, and instead of rattling, rely on natural cryptic coloration to avoid detection, it is likely that humans would pass by them and never know they were there. Those snakes would not be killed nearly as often as the ones that sang out.
Over time, the number of "quiet" ones would become more of the population, and would pass the "quiet" trait to the offspring more often. You might eventually wind up with a mute population of rattlesnakes, where the rattle serves no purpose.
The Santa Catalina Rattlesnake - Crotalus catalinensis, is a good example of this. Although closely related to the mainland Crotalus ruber, this snake has adapted to its island habitat, and over time become more elongated so that it can climb better up into trees where its major prey item is birds. It has also developed much longer fangs, which help penetrate bird feathers, and has lost the rattle, that might be a problem for a climbing snake, as it could get caught up in branches, and it could also warn wary birds.
It is easy to see here that many folks have jumped on the "rattle was developed to protect the snakes from getting stepped on by large grazing animals," theory.
Ok, that "might" make some sense for rattlesnakes that live out in open lands where grazing animals were once common. However, even in those areas, the rattlesnakes would live mostly in small rock outcroppings where the lizards and mice were found, and, thus would be out of the way of the big stupid bison and antelope anyway.
Also, one has to ask why tiny rattlesnakes like Pygmy Rattlesnakes even have a rattle ? The sound it produces is far too faint to serve as any sort of warning to a large grazing animal. Do you think that a bison really would know the difference between the sound of a 9 inch rattlesnake or a cricket chirp, or, if it would even care ? A 2000 lb bison might respect a 6 foot rattlesnake, but, it is not likely at all that it would fear a smaller one.
Also, one has to ask what purpose does a rattle serve for a montane rattlesnake? From what I can tell, large grazing animals do not climb mountains. So, what purpose do rattles serve on those snakes ? Why do they still have rattles ?
Folks often point out that non venomous snakes rattle their tails so as to "mimic" a rattlesnake, and scare away predators. Really ? So, all of the rat snakes just one day decided that they would all vibrate their tails, so that they would sound like rattlesnakes, and thus be protected ? If that were the case, then why do snakes with venom also vibrate their tails ? Is that cottonmouth or bushmaster vibrating its tail so that it can sound like a rattlesnake ? Is that cobra in Asia vibrating its tail so that it can mimic a rattlesnake, in a land where rattlesnakes never lived ?
It is quite obvious that the vibrating of tails in snakes came long before the rattle, and not Vice Versa.
Many snakes caudal lure. Tail vibration could be related to that. But, what might be even more amazing, is that if a vibrating tail were hitting the ground, or, a water surface, it would set up "sound" waves that would travel through the substrate, and could be detected by others snakes through the lower jaw, which would transfer the waves to the internal part of a snakes ear, and register as vibrational "sound," that could quickly warn other snakes of danger in a den site like area.
As far as the study about rattlesnakes getting quieter in some populations, it has been researched, and I will try to find the article again.
Fred, perhaps you should tell folks of your "economy of design, economy of metabolism and economy of lifestyle" ideas concerning the rattle.
That could really get this thread going. It is a amazing idea. Of course, it will also draw flames from those who are not able to get past being set in their ways concerning old ideas, LOL. But, what better discussion could we have while being snowed in, LOL ?
Best Regards
John Z
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by LarryDFishel on February 6, 2010
|
Mail this to a friend!
|
Archie, I thought it went without saying that I meant to take a fairly large sample.
One of two things would happen.
1) Most of these snakes would behave roughly the same in captivity with some variation between individuals. This would prove nothing.
2) There would be a statistically clear tendency of the ones from parents that lived near humans to rattle less than the ones that did not. This would not prove, but would strongly suggest, that humans were actively selecting out the lines that were more prone to rattle.
Raising them in captivity might very well be a bigger influence than genetics, leading to 1), but it would remove any develpmental influences that would invalidate 2).
For the record, I don't have much of an opinion on whether the theory is correct or not. While I can see a rattle attracting the attention of a human who might kill the snake, many won't rattle unless they are in a position where they are likely to be seen anyway and many humans will kill any snake they see. Also, some humans actually heed the warning and stay aay from rattlesnakes, so I don't know whether there is a net influence or not, but it seems plausible.
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by pictigaster1 on February 6, 2010
|
Mail this to a friend!
|
|
I know of a population of atrox and a population of viridis that are on the plains where they still graze antalope and cattle.Both of these populations are psycotic by nature.They live and hibernate in mammal burrows.You can find them easy by walking the prarie dog towns.When approached they rattle from a distance giving any hoofed animal the heads up they are there.I do find this topic interesting and FSB and John have some sound ideas .Where I live at the bottom of the great plains is where vast herds of mammals grazed for thousands of years.Yet in the canyons the atrox in large do not rattle until bothered.Further south leps will rattle and turn around in there holes in rock come out and watch you.I have found many this way.I have scene populations witch differ in the way they behave .I was just wondering at what point could a study be based.Massive populations have been wiped out in vast areas of there habitat.I love new ideas and love hearing others ideas on them.
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by pictigaster1 on February 6, 2010
|
Mail this to a friend!
|
|
Larry I am just trying to see some peoples ideas on this .Winter can be very boring .While snakes and snake people are not.This site needs topics that make people put there opinion out for others to see. This is a good topic.
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by Crotalusssp on February 6, 2010
|
Mail this to a friend!
|
I do not believe this study could be carried out with captive animals. As we all know, captive animals many times be acclimated and change from their initial behavior patterns. I also believe that this study would require a larger population or several different populations for the same species, spread over different geography. Evolution occurs at a population level, not an individual or species level. Population is defined as all individuals of a species in one area. So for example comparing populations of horridus in different areas/states would be advised. This would make the study large in terms possible population and spread over a large geography.
I have heard this idea/hypothesis for many years. While, I agree it may be very hard to test and prove statistically, I believe it would be confirmed if tested. This hypothesis would not be proven for every population, but I am confident it would be for some.
Charles
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by Cro on February 6, 2010
|
Mail this to a friend!
|
I think the biggest problem is that folks tend to want definitive answers to everything.
They want to pin things down to just one answer, where, there are actually many, many answers, as nature is extremely complex, and one population will act different from a different population.
Perhaps we should call this micro-adaption or micro-evolution.
It makes sense that populations of rattlesnakes that still live out among hoofed animals might be more prone to rattle, and populations that live in the canyons are probably more prone to stay quiet.
We make a mistake when we try to pin a one size fits all tag onto a group of animals.
Best Regards
John Z
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by pictigaster1 on February 6, 2010
|
Mail this to a friend!
|
|
Larry I am just trying to see some peoples ideas on this .Winter can be very boring .While snakes and snake people are not.This site needs topics that make people put there opinion out for others to see. This is a good topic.
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by Irishviper on February 6, 2010
|
Mail this to a friend!
|
Odd that this question would arise now? My thesis is covering such topics with lep lep and klauberi using the behaviour of their rattling. The study is complete and I am awaiting revisions, but I would be glade to discuss my findings.
Alan
|
| |
|
RE: Rattlesnake Non-rattling Study
|
Reply
|
|
by Crotalusssp on February 6, 2010
|
Mail this to a friend!
|
Alan, I for one would love to read your research and hear your thoughts/findings on this subject. Is your research specifically on reduced rattling in populations or all behavior concerning rattling?
Look forward to hearing/reading up on your work.
Charles
|
| |
|
Email Subscription
You are not subscribed to this topic.
Subscribe!
My Subscriptions
Subscriptions Help
Check our help page for help using
, or send questions, comments, or suggestions to the
Manager.
|
