Lizards go north: Balkan wall lizard population found all the way in the Czech Republic

The northernmost population of the Balkan lizard, recently discovered in the Czech Republic, has proven to be genetically unique and variable.

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The Czech Republic is a zoologically well-studied area, and its reptile fauna is not very rich. Therefore, the recent discovery of a new reptile species for the country, the Balkan wall lizard (Podarcis tauricus), came as a big surprise. This lizard inhabits areas of the Central and Western Balkans as far as Crimea, with isolated areas of occurrence in Hungary and northern Romania, so how did it get as far north as the Czech Republic? Fortunately, the genetics in much of the lizard’s range are relatively well-studied. Finding out where lizards from the Czech Republic fit genetically could reveal the origins of this northernmost population.

Podarcis tauricus in the wild – Váté písky near Bzenec, Czech Republic.

An analysis published by Czech herpetologists in the journal Biodiversity Data Journal shows that the lizards from the Czech population are genetically variable; therefore, the population was not established by the introduction of a single gravid female.

Geographical distribution of Podarcis tauricus. The green arrow shows the northernmost known locality (Váté písky, Czech Republic).

The population also has genetic “markers” not yet found elsewhere, although it is clearly related to populations from the Central and Western Balkans and Hungary. These findings suggest that this could be an original, possibly relict population.

Haplotype network, designed from 24 haplotypes of the cytb locus from 167 individuals of Podarcis tauricus and Podarcis gaigeae (Psonis et al. 2017; this study). Colours correspond to the country of the specimen’s geographical origin and each circle corresponds to a haplotype. The circle size is proportional to the number of individuals with the same haplotype. The number of individuals per haplotype is indicated. Due to the unequal size of cytb sequences from Psonis et al. (2017), only a fragment of 257 bp which was common for all 167 sequences was used for the haplotype network reconstruction. For this region of cytb locus, the sequences of our individuals from Czech Republic are identical to 18 individuals from Albania, Hungary, Kosovo and Serbia.

However, we cannot rule out recent introductions or spontaneous northward dispersal of the lizard associated with global climate change. Exotic species of animals and plants appear in the Czech Republic through various routes and tracing their origin is not always easy. Both intentional and unintentional introductions have been recorded for some reptiles, while some previously southern vertebrate and invertebrate species spread to the north spontaneously.

The first genetic data on the origin of the northernmost population of the Balkan wall lizard suggest that the lizard can spread to the north naturally; however, further investigations are needed to support this tentative conclusion. 

Research article:

Rehák I, Fischer D, Kratochvíl L, Rovatsos M (2022) Origin and haplotype diversity of the northernmost population of Podarcis tauricus (Squamata, Lacertidae): Do lizards respond to climate change and go north? Biodiversity Data Journal 10: e82156. https://doi.org/10.3897/BDJ.10.e82156