any accidental wild Tham population in Europe

[Stefan-A]

At the same time, one roman park's little lake is full of those turtles commonly found one inch small in pet shops. In the said lake, those turtles, left unopposed, have reached the size of more than 10 inches...prey on everything else, so only huge fish survive, with them, and the whole population of small fish, frogs and toads have been wiped out.

One weekend with a .17 rifle and a few boxes of ammo, and that pond would be turtle-free.

[Bart]

I believe you're talking about red-eared turtle. It's an invasive species and releasing it in EU (in Poland for sure) is a crime. In Poland there were several reports of that turtle (that fled from captivity or were released by humans) but I doubt it can reproduce in our climate (nevertheless, it can find a proper places where specific microclimate occurs I guess; probably in southern Europe it can establish real populations). But it probably can survive many years (especially winter) and decimate local populations of semi-aquatic turtles like European pond turtle (Emys orbicularis) if given a chance.

As for Thamnophis spp. in Europe, as Stefan once said, it probably can't survive, because almost all fish in Europe contain thiaminase. Maybe they >could< live solely on frogs but as we all know, Thamnophis spp. WILL hunt fish if there's a pond or the river around and snakes probably would seek actively such places or, for instance, find themselves there as a result of following amphibians (not to mention that most amphibians live close to water). Moreover, those snakes would probably hunt down european toads. They aren't immune to their venom though (unlike Natrix natrix) and would probably succumb to it.

In conclusion, the climate looks appropriate, but there's a food barrier that prevents Thamnophis spp. runaways to thrive, not to mention establishing a population in Europe. I may be horribly wrong though.

[Stefan-A]

In conclusion, the climate looks appropriate, but there's a food barrier that prevents Thamnophis spp. runaways to thrive, not to mention establishing a population in Europe.

I hope that's the case anyway.

[PINJOHN]

Moreover, those snakes would probably hunt down european toads. They aren't immune to their venom though (unlike Natrix natrix) and would probably succumb to it.

In conclusion, the climate looks appropriate, but there's a food barrier that prevents Thamnophis spp. runaways to thrive, not to mention establishing a population in Europe. I may be horribly wrong though.

establishing a population in Europe. I may be horribly wrong though. [/QUOTE]
I not sure about your European toad theory i would bet there is little, possibly no, difference in American/European toad toxins i remember one of Shannons threads where she reported huge eastern,s both size and population, that were apparently living on toads which were present in almost plague proportions

[zooplan]

establishing a population in Europe. I may be horribly wrong though.

I not sure about your European toad theory i would bet there is little, possibly no, difference in American/European toad toxins i remember one of Shannons threads where she reported huge eastern,s both size and population, that were apparently living on toads which were present in almost plague proportions[/QUOTE]
I agree that European enviroment offers enough prey for Garter Snakes. Some are proven yet by captive feeding, like earthworms, slugs, Silversides, furthermore like some newts, treefrogs, grasfrogs... mice and last but not least tadpoles have no poison or other protection than flight.
Although we don´t know any current pest population, each found "escapee" could be a specimen of an unknown habitat.

Remember the few San Francisco Garter Snakes, that were caught in official population studies in San Mateo County, CA.

[Serpico]

One weekend with a .17 rifle and a few boxes of ammo, and that pond would be turtle-free.

Lol!! I wish I could do that, maybe with salt loaded shells; but not to turtles, rather to whom freed them there! It was a beautiful little lake, now is a stinking swamp...
Seriously, they are protected as they were considered autoctone. And in Italy every wild reptile is protected.

[zooplan]

There is an old field herp study naming Thamnophis sirtalis to be neozoen in Germany:

DORSCH, A., MAUER, H., TREPTE, M. 1993: Die Amphibien und Reptilien des Main-Taunus-Kreises. Arten,
Lebensräume, Gefährdung, Schutz. Ergebnisse aus der herpetologischen Kartierung im Main-
Taunus-Kreis (1989-1993). Schutzgemeinschaft Deutscher Wald, Stadtverband Hofheim am
Taunus e.V. 91 S. + Anhang.

I had no glance at the paper and can say nothing about its´content, sorry!
Last year an adult female Plains Garter Snake was found and released at the other border of the river Rhein
only few kilometers from my home.
BTW: All my T.radix are save !!!