A Snake's hiss

[jungle jim]

Definition of unwelcome;
1. (of persons) not welcome
2. causing dissatisfaction or displeasure (a snake's hiss?)

Why do snakes hiss, beats me, so I thought I'd ask.

Some time ago I was at a show looking at the reptlle display when the snake expert went "top shelf" and extracted an Inland Taipan aka Fierce Snake. While admiring this beautiful but highly dangerous snake he began explaining some known facts about snakes. They are 100% deaf and thus demonstrated by speaking loudly up close with no response. They have very poor eyesight (up to a couple of metres only). They are aware of movement....needless to say this wasn't demonstrated.

I have had numerous snake encounters all of a passive silent nature but I am aware snakes do hiss. About a year ago I was returning along a track when I espied some distance ahead a snake (about 15-20mtrs), as I drew near it began to hiss loudly for which I was grateful because I knew where it was, beside the track lodged in a hole. The hissing continued until I was well passed.

Point is they are deaf, how do they know their hissing will be heard by others or do they have some sort of inbuilt mechanism to relieve stress or get pysched up. As their eyesight is poor I was well beyond the range limit so I can only gather its movement senses are very good. The only difference on this walk was I picked up and injury and there was a fair bit of blood so maybe their sense of smell is good.

On TV when two male snakes begin brawling over mating rights for a female I don't recall any hissing taking place. So maybe snakes know we (including other members of the animal kingdom) can hear but they can't.

Any ideas as always interested in science.

[Pteropus]

Hi jungle jim. Hissing is a defensive anti-predator strategy that is basically a warning. When many snakes feel threatened they will flatten their necks to look bigger than they are, and will hiss. This tells a potential attacker to back off. See the red belly in this pic.

red belly defensive posture

034 Red belly.JPG (291.13 KiB) Viewed 10189 times

I am not 100% sure if they hiss during combat, but there is plenty of thrashing about, and probably some hissing. They are fighting for dominance and perhaps they do not necessarily feel threatened like a potential predator would make them feel though.

Male mulga snakes in combat

168 mulga snake combat.JPG (311.88 KiB) Viewed 10189 times

But even deaf animals can make noises, and through the process of evolution, an animal that can defend itself has greater chances of passing on its genes, which might include the ability to hiss.
Here is an interesting article on snake hearing by the way -> http://news.sciencemag.org/sciencenow/2 ... -hear.html

[jungle jim]

Hello Pteropus,

Thanks for your reply.

I suspected the "hiss" had something to do with an audible warning to stay clear but after many years and numerous passive encounters its hard to work out. I read the article you suggested and this was very interesting, it appears they do have internal hearing and thus explains their awareness of hissing although the research appears very limited but positive. I am sure that as further research is undertaken our knowledge of what is holding true may completely change. The flattening of heads I have seen on TV and at some reptile shows, a highly effective visual warning.

[jackhinde]

Snakes do have some ability to detect sound, and the eyesight is very much species dependent in regard to distance they can see.
The exhalation is used as a warning, and is also as a simple "i am here" when the snake interacts with other organisms. I am able to pick up a snake bag and identify my snakes from the sound they make, tigers "cough", red bellies have a "wheeze" for example.

[north-north-west]

... tigers "cough", red bellies have a "wheeze" for example.

So not even snakes are immune to the common cold . . .

[jackhinde]

hmmmn, such jokes aside snakes have their own little viral issues, indeed one sweeping through captive collections now is known as the sunshine virus, because the first cases were in pet pythons on the sunshine coast- not because there is anything sunny about finding your serpent with its legs in the air...

[jungle jim]

Hello Jackhinde,

Thanks for you comments.

[corvus]

Snakes do have some ability to detect sound, and the eyesight is very much species dependent in regard to distance they can see.
The exhalation is used as a warning, and is also as a simple "i am here" when the snake interacts with other organisms. I am able to pick up a snake bag and identify my snakes from the sound they make, tigers "cough", red bellies have a "wheeze" for example.

In my experience our Tigers down here "bark" rather than "cough" is that because they are tougher and deadlier
corvus