Living on the edge genomic and ecological delineation of cryptic lineages in the high-elevation specialist Erebia nivalis

Cold adapted species of high elevations may be especially impacted by global warming since they might be limited in their capacity to adapt to changing conditions, or might be prevented from shifting their distributions upwards if no suitable habitats are available.The latter might be true for Erebia nivalis, a high-elevation specialist that mainly occurs in the Austrian Alps and on few mountaintops in Switzerland, where its taxonomic and conservation status remains unclear.We aimed to clarify the relationship of geographically isolated populations of E. nivalis using whole-genome resequencing data to reconstruct population connectivity and phylogenetic relationships. We inferred current and historical effective population sizes and combined these with tests for ecological differentiation based on available occurrence data, to re-evaluate the conservation status of E. nivalis.Our results confirm that Swiss and Austrian E. nivalis subspecies should be considered different evolutionary significant units, marked by moderate genomic differentiation, distinct demographic histories and a difference in the abiotic conditions of their habitats. These subspecies should be treated as independent units for conservation purposes.In both subspecies, we found rapid uphill range shifts over the last decades, little population connectivity, low current effective population sizes and low genetic diversity, especially in Switzerland. The above, combined with the low dispersal capacity of this two-year lifecycle species, and its need to overwinter under snow, which is rapidly retreating from several regions of the Alps, leads us to suggest that the status of E. nivalis should be updated to Vulnerable or Endangered in the European, Swiss and Austrian Red Lists.