eyelaser wrote:
Bill, that part about not rattling. My understanding is that there are rattlers out there that stay quiet as a recent evolutionary tactic to not being killed by people who find them more easily when they make a noise. So I am not sure the lack of rattling indicates it was "chillin"
Eric
Eric,
I don't think that applies to the AZ Black Rattlesnake. They are notoriously quiet and not very aggressive.
One study I conducted was with Mohave rattlesnakes and they are noted for being more aggressive. We surgically implanted radio-transmitters in 4 of them and replaced the batteries about every 3 to 4 months for up to a year. I found that they were more likely to remain quiet if they were concealed in cover but if out in the open they might start rattling quite a distance from me. One snake would remain quiet even though I might be only 3 or 4 feet from him when he was in cover. If he was on a road he might start rattling 20 feet away.
I would say that any trend to not rattle would be more of an adaptive behavior rather than an evolutionary trend.
normsmith wrote:
Eric,
I don't think that applies to the AZ Black Rattlesnake. They are notoriously quiet and not very aggressive.
One study I conducted was with Mohave rattlesnakes and they are noted for being more aggressive. We surgically implanted radio-transmitters in 4 of them and replaced the batteries about every 3 to 4 months for up to a year. I found that they were more likely to remain quiet if they were concealed in cover but if out in the open they might start rattling quite a distance from me. One snake would remain quiet even though I might be only 3 or 4 feet from him when he was in cover. If he was on a road he might start rattling 20 feet away.
I would say that any trend to not rattle would be more of an adaption behavior rather than an evolutionary trend.
Norm
Norm
Norm...Show more →
Norm, I love it that I can get info like that on this forum. Thanks so much for the info, and incite! Now when I rattle off my facts I will know what I am talking about or maybe I'll just keep quiet...in my case that would be evolutionary and certainly not an adaptation
Eric
Thanks again for all of the comments, very much appreciated.
Whether you admire or loath snakes, they do seem to fascinate.
I spend as much free time as possible out in the sticks looking for them. Combining another passion, photography, just adds to the satisfaction I get from seeing them in their natural habitat. I'm happy to be able to share the photographs.
Norm, awesome info! I've found scutulatus and viridis to be notorious for "going off" prematurely. I also recall a single molossus sounding off and giving himself up from under a palo verde tree while I drove by in my Jeep. He was well off the dirt road under the tree and I never would've known he was there had he not rattled.
Bill
Jul 09, 2012 at 07:18 PM
Thomas Sanders Offline • • • • • • Upload & Sell: Off
azbill wrote:
Thanks again for all of the comments, very much appreciated.
Whether you admire or loath snakes, they do seem to fascinate.
I spend as much free time as possible out in the sticks looking for them. Combining another passion, photography, just adds to the satisfaction I get from seeing them in their natural habitat. I'm happy to be able to share the photographs.
Norm, awesome info! I've found scutulatus and viridis to be notorious for "going off" prematurely. I also recall a single molossus sounding off and giving himself up from under a palo verde tree while I drove by in my Jeep. He was well off the dirt road under the tree and I never would've known he was there had he not rattled.
Bill...Show more →
Bill, viridis was the species I worked on when I was an undergrad at Oregon State, There was a den site that was the northern most for the subspecies, At least it was as far as was known at the time. My partner and I marked a bunch of them as they were coming out of hibernation. We also did all the measurements, etc. Then the next spring we did the same thing and I made a training movie on the techniques for handling and methods for future students who might continue the study. My partner was a pilot and when we flew over the area we noted some areas similar. We found another denning site a mile or so away,
Norm
If a rattler's not thermo-regulating or on the move, it's going to be coiled, both for defensive posturing and heat-conservation. It'll flick its tongue at you to see how close you're getting - a sort of 3D mapping thing. The more it flicks its tongue, the more attention it's paying.
Different species of rattlers will show different levels of aggression. If it's hissing and rattling, it's obvious what it's thinking. You also have to look at the head position. If it starts moving the head back, its likely feeling threatened. A combination of these behaviors will give you an idea of the threat-level.
Rattlers don't like turning their backs on you, so don't think that just because it's not backing off that's it's placated. Some species have to be super pissed to strike, though, and will prefer to back down, although that's not to be counted on; the Southern Pacific rattlers I see frequently are normally docile, although I got a cold welcome from a large adult guarding a younger mate's burrow. You just gotta judge each one as you find it, taking obvious precautions.
or maybe I'll just keep quiet...in my case that would be evolutionary and certainly not an adaptation 
Wonderful shots, though.