How does a constrictor know when to let go?

Wildside · 08-13-12, 07:29 PM

I've always thought snakes were able to detect a pulse. Of course that is just the most likely rational thing I could chock it up to without ever really thinking about it. Now I am genuinely curious and interested to hear everyone's knowledge or theories.

DavethePython · 08-13-12, 07:35 PM

Every time the prey ties to take a breath the snake will squeeze tighter making it harder for the prey to breathe in . Eventually they can no longer take in air and suffocate. Once the prey has completely relaxed the snake knows they are dead and let go . I am sure there is more details to it but that is the gist of it.

Wildside · 08-13-12, 07:37 PM

Quote:

Originally Posted by DavethePython

Every time the prey ties to take a breath the snake will squeeze tighter making it harder for the prey to breathe in . Eventually they can no longer take in air and suffocate. Once the prey has completely relaxed the snake knows they are dead and let go . I am sure there is more details to it but that is the gist of it.

That's certainly a better theory then my half-arsed one, let's see what else is thrown out there

shaunyboy · 08-13-12, 07:42 PM

as said when the snake exhales,the snake constricts tighter,so when the prey has FULLY exhaled,it CANNOT inhale,so death comes quickly

imo the snake can determine the prey,has no pulse,is limp,so is dead

cheers shaun

RandyRhoads · 08-13-12, 07:36 PM

I have no idea if they can or not, but when feeding pre killed to my burm she will stay wrapped around it for sometimes 10 minutes or more and clearly it doesn't have a pulse. So my guess is that it's not a big influence on when it decides to let go.

When detecting pulses only a light pressure is used. The slight pressure lets you feel korotkoff sounds (blood rushing through a partial occluded artery). Korotkoff sounds - Wikipedia, the free encyclopedia If you push down too much on an artery you occlude it and can no longer feel it. So my guess there is with the amount of pressure involved, no they cannot feel a pulse.

Wildside · 08-13-12, 07:42 PM

Quote:

Originally Posted by RandyRhoads

I have no idea if they can or not, but when feeding pre killed to my burm she will stay wrapped around it for sometimes 10 minutes or more and clearly it doesn't have a pulse. So my guess is that it's not a big influence on when it decides to let go.

When detecting pulses only a light pressure is used. The slight pressure lets you feel korotkoff sounds (blood rushing through a partial occluded artery). Korotkoff sounds - Wikipedia, the free encyclopedia If you push down too much on an artery you occlude it and can no longer feel it. So my guess there is with the amount of pressure involved, no they cannot feel a pulse.

Let's not say pulse anymore then, let's just go with heartbeat in general. My curiosity has spiked from recent debating and curiosity as to why my constrictors feel the need to constrict f/t. I used to feed live. I'm ready to throw part of my original theory out the window but I wonder if the detection of a "heartbeat", say in the neck of a human, might trigger the instinct to constrict?

knox · 08-13-12, 07:43 PM

Quote:

Originally Posted by Wildside

Let's not say pulse anymore then, let's just go with heartbeat in general. My curiosity has spiked from recent debating and curiosity as to why my constrictors feel the need to constrict f/t. I used to feed live. I'm ready to throw part of my original theory out the window but I wonder if the detection of a "heartbeat", say in the neck of a human, might trigger the instinct to constrict?

Once the snake squeezes, and the blood pressure spikes out of control, there is no longer a heart beat. The blood is not flowing, so the heart can't contract against the ventricles full of pressurized blood.

RandyRhoads · 08-13-12, 07:47 PM

Quote:

Originally Posted by knox

Once the snake squeezes, and the blood pressure spikes out of control, there is no longer a heart beat. The blood is not flowing, so the heart can't contract against the ventricles full of pressurized blood.

^^^ ..Yeah.... not sure what you mean by heartbeat rather than pulse? The electrical firing of the heart..?

knox · 08-13-12, 07:48 PM

Quote:

Originally Posted by RandyRhoads

^^^ ..Yeah.... not sure what you mean by heartbeat rather than pulse? The electrical firing of the heart..?

A pulse is the result of a heart beat.

RandyRhoads · 08-13-12, 07:50 PM

Quote:

Originally Posted by knox

Once the snake squeezes, and the blood pressure spikes out of control, there is no longer a heart beat. The blood is not flowing, so the heart can't contract against the ventricles full of pressurized blood.

With that being said now i'm curious what the heart does when this happens. Could it possibly send the preys heart into ventricular fibrilation, or would it just slow down into bradyastolic cardiac arrest. How would you even figure that one out, hook the prey up to a tiny EKG? LOL

knox · 08-13-12, 07:51 PM

Quote:

Originally Posted by RandyRhoads

With that being said now i'm curious what the heart does when this happens. Could it possibly send the preys heart into ventricular fibrilation, or would it just slow down into bradyastolic cardiac arrest. How would you even fifure that one out, hook the prey up to a tiny EKG? LOL

Definite Asystole. No matter how much the SA node is firing, the myocardium can't contract against blood that has no place to go.

knox · 08-13-12, 07:38 PM

I am not sure if they CAN feel a pulse.

In my opinion, and there is NO basis for this other than my opinion,they simply squeeze and squeeze by a mental clock. Case in point - snakes that constrict F/T prey items. They definitely sense movement, which is why they don't squeeze F/T as long as live.

One thing is for sure - though the prey might suffocate, it dies from extremely high blood pressure and lack of blood flow - a much quicker demise than suffocation.

That's my "take" on the subject.

CDN_Blood · 08-13-12, 07:39 PM

I would think if the prey is large enough, they could indeed detect a pulse. I mean, I've seen snakes flinch when flies land on them, so they're likely sensitive enough to feel the pulse, but it's the sustained lack of motion once prey has been dispatched that is their trigger for release. Some will wait longer than others, but if you were to ask me, I'd say that is what does it

moshirimon · 08-13-12, 07:57 PM

I think certain snakes know better than others. my retic would hold the rat until it was dead. my boa will hold it for hours as if she's just making sure it will be dead

Rogue628 · 08-13-12, 10:29 PM

Quote:

Originally Posted by moshirimon

I think certain snakes know better than others. my retic would hold the rat until it was dead. my boa will hold it for hours as if she's just making sure it will be dead

I have some that do each. IMO, I think alot of it has to do with what the animal has been conditioned to eat as well. I have a few animals that I feed f/t and live to....it doesn't matter to them if it's really alive or dead, the seem to hang onto their food for about the same amount of time. (these are my king, boa, and two royals)

My two dumerils and carpet were eating live before I got them. Most of their meals are f/t now (I've fed live a couple of times waiting for a new shipment of feeders to come in) and each of them will hold onto their food for a long time as if it were live. (these are also adult animals BTW).

My burms have always eaten f/t, with an occasional live one thrown in when waiting for a new shipment to come in (I can count on one hand how many times each have taken live and still have digits left over). My bigger burm will constrict her f/t for a couple of minutes, as if to make sure it's not alive and my smaller burm will pretty much start eating off the tongs without attempting to "kill" her food most times. The couple of times I have fed her live, she held onto it for a long time, I'm assuming her way of making sure it's dead. I also had switching issues with her when she was younger and was practically hand fed for about 6 months (she's a little over a year old now).

You can take my feeding experiences and observations with my animals and apply them to the subject accordingly.

Also, has any noticed a difference in what their animals eat (f/t vs p/k or live) according to that animal's feed mode? I've noticed that my carpet's feed mode isn't what it used to be when I first got her. I'm not sure if it's because I've been feeding her better meals on a more regular basis than her previous owners, as well as feeding f/t now, so she's not quite as hungry like she once probably was. I'm not sure how relevant it would be to this thread but thought I'd throw that out there as well.