Islands in the sky – could complex topography help us rewild beyond the fence?

Abstract

Context. The protection of threatened species in fenced safe havens has become a vital component of conservation management in Australia. However, despite their success, fenced safe havens face several ecological and economic constraints. There is a need to explore additional approaches to restore species beyond the fence. Aims. To explore naturally occurring mesas as potential ‘sky-island safe havens’, created by natural barriers in elevation and relief, which may restrict the movement of introduced predators and other mammals. Methods. We examined species occurrences at a mesa site (Mt. Talaterang in south-east NSW, Australia) as well as a nearby lower-lying site (Little Forest Plateau). We then provide a geospatial analysis of other mesas in NSW to investigate the number of potential sky-island safe havens in the state. Key results. Species assemblages differed between the two sites, with red foxes (Vulpes vulpes), dingoes/domestic dogs (Canis dingo/familiaris), and European rabbits (Oryctolagus cuniculus) absent from the mesa site, while Antechinus spp. were not detected from the lower-lying site. Feral cats (Felis catus) occurred at significantly lower densities on the mesa site compared to the lower-lying site. In NSW, we identified 91 other mesas of ≥10 ha with similar topology as Mt. Talaterang. Conclusions. Although differences in species assemblages are expected between different habitats, the absence of red foxes and lower number of feral cat detections at the mesa site suggest the need to further explore the potential for mesas in conservation initiatives. Implications. Our findings introduce a supplementary conservation strategy that could augment existing fenced safe haven approaches.