Distribution and habitat assessment of the Broad-headed Snake Hoplocephalus bungaroides

Conservation reserves are commonly relied on as a primary means of conserving threatened species. We conducted surveys for the endangered Broad-headed Snake Hoplocephalus bungaroides across 236 sites in 10 conservation reserves of the Sydney region, to assess the present day distribution of this species. Surveys were targeted at rock outcrops, which provide critical shelter sites during the year. Sites were stratified on the basis of proximity to walking tracks and roads as a surrogate for potential anthropogenic disturbance. Despite the apparent suitability of much of the habitat surveyed, few Broad-headed Snakes were detected and in only four of the reserves. This confirms the rarity of this species and suggests that apparent habitat suitability within conservation reserves is an inadequate basis on which to conclude that a species may be reasonably conserved. Habitat disturbance was common across the reserves, often irrespective of distance from tracks and roads. Much of this disturbance appeared to be due to activities associated with hikers and reptile poachers, rather than rock thieves as previously postulated. The abundance of loose rocks (total rocks, snake preferred rocks) varied across reserves but was not related to distance to tracks and roads, or greater at sites where snakes were detected. We conclude that the conservation needs of this species are more urgent than previously reported.