Home Range Size and Micro-habitat Density Requirements of Egernia napoleonis: Implications for Restored Jarrah Forest of South Western Australia


K. Christie, email kimberley.christie@gmail.com


Compared to natural forests, coarse woody debris (CWD) is typically scarce in restored forests due to the long time it takes to develop naturally. In post-mining restored forests in the Jarrah forest of south western Australia, CWD is returned at densities of one log pile per hectare. We tested the adequacy of these densities for meeting the micro-habitat requirements of Napoleon's skink (Egernia napoleonis), a species rarely found within restored sites. Home range size and overlap, and micro-habitat densities used by skinks, were measured by radio-tracking 12 individuals in natural, unmined forest. Napoleon's skinks had small home ranges (0.08 ± 0.02 ha), based on 8 individuals with sufficient fixes. All skinks overlapped in home ranges, with average overlaps of 43.5 ± 8.6%. Ten of the 12 skinks shared micro-habitats and 4 shared them simultaneously, which indicates some social tolerance. This will influence as to how many micro-habitats are required. Micro-habitats were used at high densities: logs at 49.2 ± 8.8 ha−1 and woody debris piles at 12.4 ± 4.8 ha−1. Based on these densities, it is recommended that CWD is returned to restored forests at densities of 60 ha−1, which should provide sufficient micro-habitats for multiple skinks. Due to the infeasibility of returning such CWD densities across large areas of restored forest, CWD could be preferentially returned as patches, large enough for numerous home ranges, adjacent to unmined forest, or as corridors between unmined forest. These recommendations for returning micro-habitats should be tested for effectiveness in encouraging recolonization of restored forest by Napoleon's skink and other species.