11 replies to this topic

[AtlantisRises]

I was Wondering if anyone knew WHY Australia had such poisonous snakes.

I was looking through several sites on the cool and deadly critters we have here and i found this table

Its based on the LD50 (the lethal dose for 50% of the animals tested on(generally mice))

Anyway i think it demonstrates how incredibly potent our snakes are.



http://www.barefootbushman.com/venoms.htm

Anyway as i said. Does anyone know why our snakes have evolved to be so potent. There are no major large predators in Australia therefore their venom is for their prey, yet surely they don't need so potent a venom for what is generally rats and native mice. Or at the largest bandicoots.

Edited by AtlantisRises, 14 October 2006 - 05:52 AM.

[RollingThunder06]

No idea. Those are some impressive numbers. Could it be the area had some past predators and even though they are no longer around the snakes have not changed?

[Col. Kurtz]

Because Australia is the freekin land of the lost..watch out for the sleestacks.

[Unlimited]

nice topic...I think it's because?? maybe the environments just right for them?

[frogfish]

The more potent the venom is, the less of it they have to use. It's an evolutionary tactic. Venom is precious to the snakes. It takes time and energy to create.

Many vipers of the Americas rank up there also...The Fer-de-lance, Bushmanster, neotropical rattlesnake, Mohave rattlesnake, Southern-pacific rattlesnake, etc.

[AtlantisRises]

OK FF but some of these snakes such as the coastal taipan is both extremely poisonous AND it deposits a very large volume of venom(http://www.barefootb...com/ptaipan.htm).

So that can not be the sole reason for the high levels of venom.

And i don't think that there was ever any major predators in Oz. I mean not many creatures are big enough to kill a 2.3 meter long Inland Taipan.

[Col. Kurtz]

I think maybe they are so poisonous because the weather is so hot,, they can kill their prey more quickly without having to use much enery chasing them down or following them while they wait for em to die. Just a thought.  

[frogfish]

Quote

And i don't think that there was ever any major predators in Oz. I mean not many creatures are big enough to kill a 2.3 meter long Inland Taipan

Venom is not for defense, it's main purpose is for hunting. I still believe that the reason the venom is so highly toxic is that so they use less for HUNTING.

[REBEL]

Quote

OK FF but some of these snakes such as the coastal taipan is both extremely poisonous AND it deposits a very large volume of venom(http://www.barefootb...com/ptaipan.htm).

So that can not be the sole reason for the high levels of venom.

And i don't think that there was ever any major predators in Oz. I mean not many creatures are big enough to kill a 2.3 meter long Inland Taipan.

On that list u posted A ,...I've never seen so many ''common brown'' this year as to any other year on the farm, and summer has'nt even  kicked in yet.
Talking to the local vet who told me that one bite from this snake can kill an adult in only a few minutes. Then a small child virtuely has no chance, pretty frighting stuff.

[REBEL]

Quote

I think maybe they are so poisonous because the weather is so hot,, they can kill their prey more quickly without having to use much enery chasing them down or following them while they wait for em to die. Just a thought.  

Good Point.

[AtlantisRises]

Quote

Venom is not for defense, it's main purpose is for hunting. I still believe that the reason the venom is so highly toxic is that so they use less for HUNTING.

That was directed at Rolling Thunder.

[ohio tsunami]

I've heard some interesting theories on a few shows on Discovery & National Geagraphic channels that maybe because of the isolation of Australia (being a large island of sorts) led to different evolution of animals than else where in the world.  Example duck-billed platypus(spelling?).  Sorry, I don't have any direct links to these theories.  Maybe these poisonous snakes, spiders, and the platypus evolved more deadly venom because of the different set of rules of the environment.  I will agree, though I'm not afraid of snakes, I wouldn't want to come into contact with the majority of snakes in Oz.