“…Divergence among the resulting clusters is the shallowest across our study, but the estimated divergence time falls outside the 95% confidence interval for this estimate (Table 4), suggesting a lack of support for this western split, in agreement with the Procrustes results and second-best K from the STruCTure analysis (Table 1) southern South Island has been less well studied phylogeographically than the north, probably due to the near absence of glacial refugia, inaccessibility of its southwest corner, and extensive deforestation. However, the Haast corridor has proven important as a potential glacial refugium (Weir et al, 2016) and contact zone (Davis et al, 2019) for lineages of multiple species. For B. scutellaris, expansion into the south from the east as well as via Haast highlights that the Otago highlands may be more permeable to some species than the topographic barriers delimiting northern South…”