Elevational Distribution Patterns in an Australian Subtropical Rainforest Lizard Fauna

Abstract

Baseline data are critical to understanding the impacts of climatic change on the distribution of animals and plants. Here we present the results of elevational surveys for rainforest lizards along two routes in Lamington National Park in subtropical eastern Australia. Surveys were particularly focused on two threatened montane species: Harrisoniascincus zia and Silvascincus tryoni. Survey results were numerically dominated by four abundant taxa (including the two threatened montane specialists), although 10 species were recorded in total. Silvascincus tryoni was found to have a very narrow elevational distribution, with a considerably lower probability of occupancy at lower elevations where the congener S. murrayi dominated. The two focal montane specialists extended to significantly lower elevations along a deep gully and creekline when compared to a geographically proximate and broadly parallel ridgeline. Species in another genus of lizards—Saproscincus—were also far more abundant along the creekline. These data emphasise the potential importance of landscape heterogeneity in enabling both the elevational distribution of species in this community and their potential resilience to rising temperatures under climate change. These detailed data on lizard species that are relatively easy to survey and identify, and show contrasting distributions closely associated with elevation and temperature, provide a baseline for detecting future changes in Australia's subtropical montane rainforests.