Stephen Beatty

This data set contains size and/or sex data from 41,021 freshwater turtles from 38 species and 428 populations located in parts of Australia both with and without introduced foxes, as well as populations in the United States of America, which naturally have raccoons (Procyon lotor), foxes, and other nest predators. The goal was to examine population-level body size distributions to establish a baseline for “typical” turtle populations and test whether populations that are exposed to introduced foxes have proportionately fewer juveniles compared to both AU populations that lack introduced foxes and USA populations that are naturally exposed to nest predators. We additionally conducted analyses on the biases of trapping methods, effects of sample size, and effects of water body type. This data set was assembled by pooling the data from numerous researchers.

Anthropogenic climate change is forecast to drive regional climate disruption and instability across the globe. These impacts are likely to be exacerbated within biodiversity hotspots, both due to the greater potential for species loss but also to the possibility that endemic lineages might not have experienced significant climatic variation in the past, limiting their evolutionary potential to respond to rapid climate change. We assessed the role of climatic stability on the accumulation and persistence of lineages in an obligate freshwater fish group endemic to the southwest Western Australia (SWWA) biodiversity hotspot. Using 19,426 genomic (ddRAD-seq) markers and species distribution modelling, we explored the phylogeographic history of western (Nannoperca vittata) and little (Nannoperca pygmaea) pygmy perches, assessing population divergence and phylogenetic relationships, delimiting species and estimating changes in species distributions from the Pliocene to 2100. We identified two deep phylogroups comprising three divergent clusters, which showed no historical connectivity since the Pliocene. We conservatively suggest these represent three isolated species with additional intraspecific structure within one widespread species. All lineages showed long-term patterns of isolation and persistence owing to climatic stability but with significant range contractions likely under future climate change. Our results highlighted the role of climatic stability in allowing the persistence of isolated lineages in the SWWA. This biodiversity hotspot is under compounding threat from ongoing climate change and habitat modification, which may further threaten previously undetected cryptic diversity across the region.