Reptile & Amphibian Forums

It seems that it should be rather easy to find out how many species of snakes are venomous in North America. However I cant get a number. Does anyone here know how many native species of venomous snake we have?

Thanks:
JasonMc

Depends on the definitions of "North America" and "venomous", but if you mean "continental US and Canada" and "dangerous to humans", you come up with about 20, depending on particular taxonomic scheme followed.

Thanks for the response! Thats what I was counting as well. It just seems like their are more.
Thanks again:
JasonMc

>>It seems that it should be rather easy to find out how many species of snakes are venomous in North America. However I cant get a number. Does anyone here know how many native species of venomous snake we have?
>>
>>Thanks:
>>JasonMc
>>

Actually it is anything but easy. It all depends on how one defines "species." Some taxonomists consider practically every geographically isolated population a different species (the so-called 'Evolutionary Species Concept') or every mtDNA lineage as a different species, whereas other taxonomists are more conservative and only count species according to the Biological Species Concept.

And there has also been a dispute on the definition of venomous as well. There are some garter snake bites that have been known to produce toxic effects, and some of these can be attributed to allergic reactions to the bites. Nevertheless, there is an attempt to label these snakes "venomous" because of the toxic effects of their bites. Without an agreement on definitions of venomous and species, one can never arrive at a consensus as to how many venomous species are found in the United States.

I failed to mention that I was just looking for the more severe venomous snakes. However as you mentioned, their are many other mildly venomous, rear fanged snakes like the Hoggnose, racers, and what I think ive been hearing, the corn snakes. As you know rear fanged mildly venomous snakes can be equally deadly depending on the reaction of the bite to the person bitten.

Thanks for reminding about the mildly venomous snakes. I totally overlooked them!

JasonMc

>>I failed to mention that I was just looking for the more severe venomous snakes. However as you mentioned, their are many other mildly venomous, rear fanged snakes like the Hoggnose, racers, and what I think ive been hearing, the corn snakes. As you know rear fanged mildly venomous snakes can be equally deadly depending on the reaction of the bite to the person bitten.
>>
>>Thanks for reminding about the mildly venomous snakes. I totally overlooked them!
>>
>>JasonMc >>

There is absolutely no evidence to show that the ratsnakes and their descendants (kingsnakes, gopher snakes et al.) are venomous or even toxic. There has been a claim that the common ancestor of all the colubrid snakes was venomous, but that is a real stretch of reason and imagination. Using that particular definition of venom, human saliva can be considered venom and human beings are venomous, which is of course absurd.

Of course the number of venomous species can be exaggerating by the splitters, taxonomists who like to propose new species on the basis of differences that most other taxonomists would consider trivial.