Experimental rock outcrops reveal continuing habitat disturbance for an endangered Australian snake

Protected areas are commonly viewed as safe havens for endangered species. To test this notion, we experimentally constructed small rock outcrops for the endangered broad-headed snake (Hoplocephalus bungaroides) within a nati onal park near Sydney, Australia. Rock outcrops provide vital shelter sites during the cooler months of the year. Constructed rock outcrops (3 x 5 m) were placed at II paired sites located near (less than or equal to 250 m) a nd far from (>400 m) walking tracks and roads. Eight of our 22 rock outcrop s were disturbed by people over a 15-month period. Disturbance consisted of displacement of some rocks or complete destruction of the outcrop. Disturb ed outcrops occurred up to 450 m from a walking track or road. Disturbance to natural outcrops has also been observed in this park. This demonstrates a continuing decline in the quality of this snake's habitat. Twenty of our rock outcrops were colonized by velvet geckos (Oedura lesueurii), the prima ry prey of this snake. One broad-headed snake was found in one outcrop. Acc ording to these findings, attempts to restore the habitat of this endangere d snake should be centered on sites located greater than or equal to 500 m from a walking track or road. Our study highlights the value of targeted ex periments that precede larger-scale habitat restoration.