The effects of body size and introduced predator exclusion fencing on reptile detection and occupancy

The feral cat and fox have been implicated as a key threatening process contributing to 90 native species extinctions. The feral cat and European red fox predation pressure vary in how native species are influenced affect their species-specific traits, including body size. Predator exclosure fencing was used as predator suppression due to previous positive biodiversity responses. The study species were seven lizards, encompassing a range of body sizes. Five detection methods were used, and these were replicated at 22 sites, 10 within the fenced area and 12 outside. These effects of detection (p) and occupancy (Ψ)probability were modelled as Single Season Multi-Method models via the software PRESENCE. Method specific and species effect were the most significant for cross-species detection (p) probability and method-specific was most significant for each species. The Pitfall trap was the most detected trap in the study. Predator exclusion fence and body size effect were most influential for occupancy (Ψ) probability across species with an overall negative effect. Small body-sized species occupied outside the fence area more whilst reflected across single-species occupancy (Ψ) probability, larger bodied study species eastern striped skink, shingleback skink and the varanids all occupied more positively inside the fenced exclosure. These results suggest though the predator exclusion fence is a valuable tool for protecting native biodiversity, further research will need be to conducted to ensure that predator exclusion fencing also provides a positive occupancy outcome for smaller bodied lizards.