Size and structure of populations of Oedura reticulata (Reptilia: Gekkonidae) in woodland remnants: Implications for the future regional distribution of a currently common species

The gecko Oedura reticulata is restricted in distribution to the southwest of Western Australia. Within this region O. reticulata occurs mainly in smooth-barked eucalypt woodland habitat, much of which has become fragmented by clearing. In this study, demographic characteristics of nine populations of O. reticulata that currently persist in eucalypt woodland remnants are assessed and compared with those of populations in three nature reserves. The remnants cover a range of sizes but are similar in age, tree species composition and vegetation structure. Population sizes vary considerably among remnants and are poorly correlated with remnant size or the number of smooth-barked eucalypts. Population size does not appear to be limited by habitat availability in most remnants. The number of adults of breeding age is small in most populations suggesting that they may be susceptible to stochastic extinction pressures. The poor dispersal ability of this species between remnants means that the possibility of recolonization of a remnant following an extinction event is unlikely. As a result, the occupancy rate of O. reticulata in remnant woodland is likely to decline.