Natrix helveticus or natrix

[Peter Engelen]

This weekend I found a Natrix in Belgium, Limburg, Maasmechelen. This is a location where Natrix is not native. After a few mails I know that in 2004 there were 2 Natrix released in a factory that makes fertilizer. They import a lot of horse manure. They came from Schwalmtal, Germany.

Which subspecies lifes here. Is this natrix or helveticus, or something in between?

Peter

[Peter Oefinger]

The areas west of Rhine river in North Rhine Westphalia have helvetica
http://www.herpetofauna-nrw.de/reptilie ... /index.php

[Peter Engelen]

Thanks Peter.

Now we can begin to discuss in Belgium if we are taking measures to protect these introduced species or not. Red list in Flanders Natrix is as endangered

Kind regards,

Peter

[Peter Oefinger]

see also here:
http://www.herpetofauna-nrw.de/arbeitsk ... /index.php
If you scroll down the page you will find maps for natrix, helveticus and hybrids. Unfortunately the Schwalmtal spot is not included but it is obvious that the Western Rhine populations tend to be helvetica.