Determining the geographic distribution and ecology of the Critically Endangered Kaputar rock skink (Egernia roomi)

Abstract

Context Knowledge of species’ distribution and habitat associations is fundamental for conservation planning and management, especially in the context of range-restricted taxa. The Critically Endangered Kaputar rock skink (Egernia roomi) is a high elevation species that is restricted to the Nandewar Ranges (New South Wales, Australia). The species was not formally recognised until 2019, with its distribution, ecology, and threats poorly known. Aims To determine the geographical distribution of the Kaputar rock skink and explore its ecology and threats. Methods We performed surveys throughout high elevation regions of Mount Kaputar National Park, targeting suitable habitat for the Kaputar rock skink (rock outcrops and plateaux). Species distributional modelling (SDM) was used to identify potentially suitable habitat outside of our search areas. Key results We detected the species at all historical record sites and at 15 new sites, increasing the species’ known area of occupancy (AOO) four-fold (from 8 km2 to 40 km2), and elevational range three-fold (from 1360–1480 m to 1147–1509 m). Conclusion The AOO for the species now exceeds the IUCN Red List threshold for Critically Endangered, but falls within the range for Endangered under Criterion B. Our SDMs indicated that all predicted suitable habitat for the species falls within the region that we surveyed in this study. Implications Our study provides valuable information on the geographic range of a threatened lizard species and evaluates the potential impact of large-scale fires on the persistence of the species.