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Re: Hierophis viridiflavus feigning death when handled

PostPosted: Wed Jan 10, 2018 8:09 pm
by Ruggero M.
Berislav Horvatic wrote:
Mario Schweiger wrote:Yes, that it was, after a lot of guys want to get pictures and always tried to do the snake ikebana. but the snake disnt turn upside down, just got completely relaxed, like dead. after some minutes (for sure it seems longer as it has been), she got alive again.
something like that also happened with a Dolichophis caspius on Ada Bojana.


Mario, I would say your snake just fainted. It happened to me once with a Vipera berus bosniensis. It was hot,
and I insisted on making photos in full sunshine. I was prepared to bear the heat, but the snake was not. The
photo session lasted for much too long, since the viper was not "cooperative", it just wanted to run away into
some shade. Suddenly it fainted. I was very much ashamed of myself and my ruthlessness. I hurried with it
into the nearby shade, where it soon recovered.


Could the same thing have happened to the viridiflavus of the picture?

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Wed Jan 10, 2018 11:10 pm
by Ilian Velikov
Certainly a very interesting discussion that brings a lot of questions to my mind. Berislav's fainting theory makes sense. I guess snakes are so different that we forget they could faint like any other living thing. However, I was wondering how does a snake faint? Why would they turn on their back? It's not like they were standing up and fell down. Why would they not just relax and loose consciousness? Then I started thinking about other species in which "feigning death" is confirmed. My knowledge on the subject is rather limited and I only know about the N. natrix and N. tessellata doing this (any others?) but could this behavior be related to exposing the "warning" chequered pattern of black and white/orange/red on the belly that might act as a repellent to predators rather than actually feigning death?

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 12:44 am
by Berislav Horvatic
Ilian Velikov wrote:Certainly a very interesting discussion that brings a lot of questions to my mind. Berislav's fainting theory makes sense. I guess snakes are so different that we forget they could faint like any other living thing. However, I was wondering how does a snake faint? Why would they turn on their back? It's not like they were standing up and fell down. Why would they not just relax and loose consciousness?

As for me, it's been just a single (very unpleasant) experience, no "theory" in any sense. Yes, the snake fainted
like any other living being, no "display"... Of course it did not turn on its back, just fainted... lost consciousness,
if you like. Lay flat and motionless and irresponsive... "Feigning death" is something quite different from that...

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 9:51 am
by Ilian Velikov
Berislav Horvatic wrote:As for me, it's been just a single (very unpleasant) experience, no "theory" in any sense.


I was refering to this

Berislav Horvatic wrote:Mario, I would say your snake just fainted.


And my question about how snakes faint was following Ruggero's question

Ruggero Morimando wrote:Could the same thing have happened to the viridiflavus of the picture?



Berislav Horvatic wrote:"Feigning death" is something quite different from that...

Yes, but could it be that it's just us that interpret it as "feigning death"? I still struggle to see how this would be an effective defense mechanism. The snakes are cought pretty much alive and after some struggle they turn belly up and "pretend to die"...Wouldn't any predator want exactly this? Catch its prey, kill it and eat it. How would this change the predator's mind to eat the snake? Not to mention that most snake predators (mainly mammalian) would happily scavenge a dead snake as well. And after all when snakes actually die (or faint) they don't turn on their backs as you pointed. So why do it when pretending to die? So I was wondering if the "warning" colours of the Natrix belly play some role.

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 11:10 am
by Alexandre Roux
I've seen one doing this a few years ago when I was young and felt like I was obligated to handle every snake I saw :roll:
I was with a friend who was stunned by this behaviour and thought every whip snake do that, so he tried with a second one. I think he still remembers that was not a good idea :lol:

Saw that kind of thing too:

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 12:37 pm
by Mario Schweiger
here another example.
But why a nearly 2.5 meters long and 7.5 kg heavy Python bivittatus should play death when handled?
https://www.researchgate.net/publication/321803820_DEATH_FEIGNING_BEHAVIOR_IN_THE_BURMESE_PYTHON_Python_bivittatus_KUHL_1820_IN_CHITWAN_NATIONAL_PARK_NEPAL

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 1:01 pm
by Ilian Velikov
Alexandre, the behavior from your video doesn't look like "feigning death" to me but rather like the snake is coiling into a ball to protect its head - a very common defensive behavior in most (if not all) snakes.

Mario Schweiger wrote:here another example.
But why a nearly 2.5 meters long and 7.5 kg heavy Python bivittatus should play death when handled?


Good question Mario. The article also says "factors associated with display of such a behavior are considered owing to avoid predators and maximize probability of their survival". While in mammals such as the opossum feigning death is displayed when danger is sensed, before the predator has cought the opossum (e.g. when an eagle flies nearby), in snakes this behavior is displayed once the snake is cought and often after some time of struggle and trying to escape. So how is this avoiding predators? Also from all the N.natrix I've cought (which are a lot) only one individual did feign death and I've never observed this in the numerous tessellata that I've cought. Why would such behavior be so infrequent/rare if it was actually avoiding predation?

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 1:42 pm
by Michal Szkudlarek
Why would such behavior be so infrequent/rare if it was actually avoiding predation?

Maybe selective pression was low because these snakes are not being preyed upon often.

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 1:51 pm
by Ilian Velikov
Michal Szkudlarek wrote:because these snakes are not being preyed upon often.

I'm not sure if this is true. In big parts of their range they co-exist with many predators that would feed on them, some of which do so regularly. Some that come to mind are storks, herons, otters, foxes, other snakes, and when young even frogs/toads, fish and so on. But I don't see how "feigning death" would be effective against any of these.

Re: Hierophis viridiflavus feigning death when handled

PostPosted: Thu Jan 11, 2018 2:14 pm
by Michal Szkudlarek
But I don't see how "feigning death" would be effective against any of these.

The possibility of being killed is lower if you feign death because predators prefer eating animals which are evidentially alive.