The benefits of habitat restoration for rock-dwelling velvet geckos Oedura lesueurii

摘要

Worldwide, efforts to restore habitat quality are rarely matched by efforts to evaluate the effects of those restoration attempts. Simply documenting usage of the newly created habitats by biota is not enough, because such areas may serve as sink populations. We need to monitor viability (growth, survival, reproduction) of individuals that colonize the newly created habitat, compared with conspecifics in non-restored areas. In the Sydney region in south-eastern Australia, humans have degraded sandstone rock outcrops by removing natural rocks for landscaping urban gardens. We restored degraded rock outcrops by placing artificial rocks at sites where natural rocks had been removed. We measured growth rates and survival in velvet geckos Oedura lesueurii at control and restored sites over a 2-year period. Gecko growth rates were unaffected by habitat restoration, but restoring sites with artificial rocks increased the overall numbers of lizards detected (both adults and juveniles). The apparent survival rates of adult male lizards (as estimated using mark) were not significantly affected by habitat restoration. However, apparent survival rates of juvenile geckos were higher at restored sites than at unrestored sites. Synthesis and applications. Habitat restoration using artificial rocks has had measurable conservation benefits on these degraded rocky outcrops. Quantifying those benefits in terms of species' survival and growth rates enables management decisions about habitat restoration to be based upon evidence rather than wishful thinking or untested intuition. Habitat restoration using artificial rocks has had measurable conservation benefits on these degraded rocky outcrops. Quantifying those benefits in terms of species' survival and growth rates enables management decisions about habitat restoration to be based upon evidence rather than wishful thinking or untested intuition.