Genetic diversity and biogeographic history inform future conservation management strategies for the rare sunset frog (Spicospina flammocaerulea)

Abstract

Outlining the distribution of genetic variation, patterns of gene flow and clarifying the biogeographic processes underlying population history are critical components of a comprehensive conservation strategy for endangered or vulnerable species. We provide this information for the vulnerable sunset frog (Spicospina flammocaerulea) using a comprehensive genetic dataset (ND2) with samples from 17 of 22 geographic localities where this species has been found. From genetic, biogeographic and coalescent-based analyses, we document the existing genetic variation, likely movement patterns and explore the biogeographic history of S. flammocaerulea. While catchment-based genetic variation is well documented in other high-rainfall taxa in south-western Australia, a much more complex scenario including dispersal across ridge lines between catchments better explains the distribution of genetic variation and observed patterns of gene flow in S. flammocaerulea. The population history of S. flammocaerulea is strongly indicative of recent population contraction and expansion, which may be related to late Pleistocene climate fluctuations. This suggests that this species can adapt or move in response to fluctuating climates provided suitable habitats or expansion areas are available. However, like many other endemic taxa with limited geographic ranges in south-western Australia, the potential to shift distributions is hampered by being land-locked within an agricultural landscape, limiting management options in the face of climate change. © 2011 CSIRO.