Quote Originally Posted by chris-uk View Post
I think the environmental conditions aspect is a consideration when housing any snakes together. That many garter species have such a large range makes it easy to put different species together, but I'd still shy away from putting garters together where their natural envionmental conditions varied greatly. What is significant is that the Canadian garters still operate in similar temps to Mexican garters, the difference being the months that they are active. That garters tend to be very adaptable helps keep them together. Similar story with natrix, for example I've read about a population of natrix tessalata living in Poland, when they are normally found further south so there's a adaptability in natrix as well. Whether all species of natrix and thamnophis could be safely kept together... I don't know, we'd have to consider each combination and decide.

Pathogen crossover between thamnophis and natrix is an unknown until someone produces the research that says that a virus/bacteria/other pathogen commonly and harmlessly carried in one genera has ill effects on the other. There's two ways to approach an unknown risk, either assume it is a high risk until proven safe, or assume it is not a risk until it proves otherwise. As with many things we make a risk assessment and decide how to react based on our perception of the risk.
OK then Chris based on my personal experience of keeping these snakes together, i deem it to be risk free there you go i have said it and it is of course just my opinion ....and i don't seem to have aquatically explained that when mixing the two then i am referring to snakes of comparable latitudes not to one from each extreme, i honestly thought that was a given but people keep coming back to the extreme position.