Wednesday, April 11, 2012
Consider the Eastern Diamondback rattlesnake, for example. The normal venom yield is 492 to 650 mg when the snake is milked. The lethal dose for this snake is considered to be about 100 mg of venom. That means an Eastern Diamondback bite has a very good chance of being lethal, because the snake can inject only a fraction of it's venom load into the victim in order to cause death.
Now compare that with the Sidewinder rattlesnake. The normal yield of venom ranges between 20 to 35 mg per milking, and the lethal dose is considered to be 40 mg. This snake can unload its entire venom capacity and still not hit the lethal threshold.
Again, I stress that this does not mean the Sidewinder is not a dangerous serpent. It is. In fact, note that it takes less than half the amount of a Sidewinder's venom than that of an Eastern Diamondback to be considered deadly to humans. So the venom is very potent. It's just that the snake doesn't normally produce enough to cause human death.
The rule for safety in snake country is to be very watchful to prevent an encounter. Avoid snake habitat such as old buildings, ledges, bushes, debris piles, etc. If you spot a snake, leave it alone. Most venomous snakebites to humans happen because the person messed with the snake on purpose. Fewer than 20% of snakebites occur purely by accident.