From the Woods to the Great Steppe: The Phylogenetic Affinities and New Distribution Records of the Smooth Snake Coronella austriaca in Kazakhstan

The smooth snake (Coronella austriaca) has a wide but fragmented distribution across the Western Palearctic, with limited records in Kazakhstan. This study aims to provide an updated distribution map and to explore the phylogenetic affinities of C. austriaca in Kazakhstan. The species had not been documented for over 60 years until its recent rediscovery in the region. Field surveys conducted between 2019 and 2024 in the West Kazakhstan and Aktobe regions have yielded novel records, including the southernmost observation in the Mugodzhar mountain range. Mitochondrial DNA analysis confirmed that the Kazakh populations belong to the Eastern lineage, sharing haplotypes with specimens from the northwestern Caucasus and Crimea. Habitat assessment revealed that the species’ distribution is restricted to open habitats of petrophytic and calciphyte steppe communities on chalks and rocky steppes. Of particular interest is that 70% of the observed individuals exhibited patternless coloration, suggesting the potential for regional morphological variation. These findings offer the first evidence for the phylogenetic affiliation of the smooth snake in Kazakhstan and reflect its rarity in the country, highlighting the need for local conservation efforts, including habitat protection and population monitoring.