Persistence of Australia's most threatened snake (Hoplocephalus bungaroides) in Australia's oldest National Park

Abstract

Evaluating the ecological effectiveness of protected areas is fundamental to understanding their value as a conservation tool. Investigating whether protected areas can retain highly threatened species should provide a rigorous test of their effectiveness. I used occupancy modelling to investigate population stability of a threatened venomous snake over a 16-year period in the 135-year-old Royal National Park in Australia. I predicted that if the broad-headed snake (Hoplocephalus bungaroides) was in decline then the probability of occupancy should decline over time and the age structure of the population should shift due to the species' slow life history traits. The occupancy-based finite rate of increase remained just above 1.0 throughout the study, and the age structure remained unchanged, suggesting population stability. Modelling provided some support for hypotheses that distance to roads and walking trails influenced the probability of site extinction, while the number of occupied adjoining sites increased the probability of site colonization. There was no influence on site occupancy of a wildfire that occurred 4 years into the study. My findings suggest protection of habitat at specific locations may be sufficient to conserve this species but further population monitoring should occur to confirm this. My study shows that protected areas with high public visitation can play an important role in biodiversity conservation.