Diversity of Austrian amphibians and reptiles

The present distribution of amphibians and reptiles in Central Europe is generally considered as the result of post glacial and thus relatively young colonisation from glacial refugia. In a few species glacial isolation in different areas has led to clear distinguishable morphological differences in groups of populations, which presently are considered as subspecies or semispecies, respectively. So far, genetic investigations have only, been performed on a few species, and Austrian samples were of only marginal importance. We have performed preliminary investigations of Austria specimens of Common lizard (Zootoca vivipara), adder (Vipera berus) and Grass frog (Rana temporaria). The results indicate major genetic differences within so-called subspecies. These are probably also due to the long-lasting isolation in glacial refugia. In the course of the project a genetic analysis of 5 species of reptiles (Zootoca vivipara, Podarcis muralis, Lacerta agilis, Anguis fragilis, Vipera berus) and 4 species of amphibians (Rana temporaria, Rana arvalis, Bufo bufo, Triturus alpestris) will be performed covering the whole territory of Austria and including samples from neighbouring regions. The goal of the study is to establish hypotheses about glacial refugia for the species investigated and also to reconstruct postgalcial routes of colonisation. Moreover, the knowledge about intraspecific biodiversity is of highest importance for conservation purposes. It is planned to sequence parts of the mitochondrial genes coding for 12SrRNA and 16SrRNA (together approx. 950 bp) for all samples. For species showing only little differences in those genetic regions, we will also investigate the control-region (section of the mitochondrial genome showing the highest evolutionary speed). Furthermore, using nuclear genes (allozyme--electrophoresis), the degree of hybridisation and gene flowin contact zones with distinctly different haplotypes will be examined.

In the course of the project we analysed mitochondrial DNA markers of more than 400 reptile samples of four Austrian species, Podarcis muralis (Wall lizard), Zootoca vivipara (Common lizard), Vipera berus (Adder) and Vipera ammodytes (Long-nosed viper). The samples came from localities distributed over the whole ranges of the respective species. All these species showed remarkable geographically correlated intraspecific differentiation. From the recent distribution of the different "Austrian" haplotype groups and taking into consideration the known climatic preferences of the species we were able to identify the probable Wurm glacial refugia and post-glacial colonisation routes to Austria for all relevant haploclades. We found three clades of the Wall lizard, the first one from the populations from Carinthia and the eastern border of the Alps, the second one from the Inn valley and the third one from two small isolated areas in Vienna and Lower Austria, respectively. With the common lizard we found four main clades, one of them corresponding to the subspecies Z. v. carniolica in Carinthia (oviparous), the other three corresponding to different population groups of the nominate form (ovoviviparous). Three clades of the adder were found, the first in the populations occurring in the north of the Danube, the second one in Vorarlberg and northern Salzburg, and the third one widely distributed in the Alpine regions. I constrast to that only a single haplotype was detected in the Austrian populations of the Long-nosed viper. The high differentiation of the investigated Austrian reptile species, especially of the two lizards, is an important basis for specific conservation strategies. At least two of the wall lizard groups have very restricted areas in Austria, and one group of the Common lizard may be endemic.