Why are Australian snakes so toxic?

[InfiniteNow]

That's why I prefaced by saying "easy answer." Maybe I should've said "the sort of correct, but not complete" answer.

[Racoon]

Originally Posted by Eskimo Joe

Hi there folks...
It's a well known fact that most Australian snakes are very toxic, and most of the worlds most toxic snakes are found here. Why is this, why are they so much more toxic than snakes in other parts of the world? Can someone give me a answer on this from a biogeographical and evolutionary view...

There are a few poisonous spiders there as well mate.
Australia has some really neat-o species.

So many things that can kill you,
So little time.

[Boerseun]

Would've been ace cool if they had marsupial spiders!

[bpjg2fat]

eeeee

[Jay-qu]

lol its a dangerous job living down under, but someone has to do it!

[Michaelangelica]

I am not sure that Australia has THE most toxic snake.
We do have some good ones though.
Death by snakebite, however is rare as all respond to a pressure bandage which can give you 1-2 days to seek help. A pressure bandage stops the venom travelling through the lymph system. (venom does not travel in the blood so tourniquets are useless.)
There is a plentiful supply of anti-venom provided by places like the Australian Reptile Park a few miles from me at Somersby Australia (they may have a web site?). I think India has the most deaths caused by snakebite.

However venomous they are, Australian snakes are in dire (like extiction ) trouble. This is due to the silly introduction of the South American Cane Toad into N. Australia (Queensland) as a biolgical control to help sugar farmers. The toads have now taken over most of Queensland, in plague proportions. They are now moving south into NSW and west into NT threatning World Heritage areas like Kakadu National Park.
(There are no native toads in Australia)
Snakes eat the toads and are killed by a poison gland in the toad's "neck"

Australian snake venom is the souce of some unique and potentially useful chemicals and some research is being done on this in many Aust. universities.

Michael

[Ganoderma]

aus has some toxic stuff but so does africa and to a lesser extent asia.

i like to think along the lines posted above about environment. its just how they evolved. its a good observation about predators as well compared to north america. look at the climate. reptiles are cold blooded and there are many many COLD spots in canada and the usa (thats where i am from by the by). its possible that in colder climates prehaps not only a limited amount of species branching off but perhaps also a slower evolution? just a thought. also notice that there are a lot of species in NA that cover a LOT of ground (garters for example). i have often wondered about environmental factors and speciation. barriers like islands, mountains etc...

although perhaps not AS toxic to *people* most other warmer countries (especially those with areas of no freezing temps) have quite toxic snakes.

yes, aus has very toxic snakes, but i think it is played up a little too much...

[Michaelangelica]

Originally Posted by Ganoderma

aus has some toxic stuff but so does africa and to a lesser extent asia.

yes, aus has very toxic snakes, but i think it is played up a little too much...

Agreed.
We mainly use them to scare New Zealanders.
It is a National Pastime.

The Crocks are the ones that usally eat the Yanks. (They, (the Yanks), think they are Alligators)

[Ganoderma]

figured as much....they will believe anything eh?

i always thought you guys in OZ liked yankees...

Another thought is some snakes in the Americas have far better defense mechanisms so perhaps do not need the strength that Australian snakes do. I remember watch a program on discovery channel (I think they were using cobras) testing the differences in amounts of venom used for offensive (eating) and defensive strikes. it was a fair bit more in the defensive which makes sense. So.....if one of the big reasons for having venom is defense and you have other forms of defense (especially pit vipers) the venom strength may not be so important. NA's snakes also seem to be more so sit and wait while more of Australians are, for lack of a better word, hunters.

Delivery systems may play part as well. Australia has some large fanged snakes, like adders, but not much beats the length of a viper...perhaps the physical aspect of having smaller fangs means not as much venom is delivered meaning potent counts. Again, just thoughts.

[Michaelangelica]

Originally Posted by Ganoderma

figured as much....they will believe anything eh?

i always thought you guys in OZ liked yankees...

Crocs love them.
Especially those that go fishing in the Alligator River.

Crocs havent changed their genetic makeup for about 600 mil. years. They don't need to. They are mean SOBs. One ate a little 8 YO aboriginal girl yesterday.
The local Aboriginal Nation did not want any crocs killed as it is their sacred totem.

Snakes are not a problem in most of OZ.
I am surprised, however, that the USA does not use the lymph pressure bandage as first aid. It gives you 12-24 or more hours to get help from even the most deadly of snakes. Are Yanki snakes different?