The golden-tailed gecko: a disturbance-tolerant species in a fragmenting environment

Abstract

Context: In central Queensland, Australia, the development of a coal-seam gas (CSG) industry is creating additional fragmentation of landscapes consisting of woodland and open forest that are already highly fragmented. Aims: To assess the response to fragmentation of Strophurus taenicauda (golden-tailed gecko). The species is 'near threatened' in Queensland. Methods: Occurrence and abundance were examined across three categories of patch size-small (≤10 ha), medium (10-100 ha) and large (≥100 ha)-across three geographic areas of the species' range. Minimal impact (i.e. sighting only) active searches for geckos were conducted at night. A minimum of three replicate sites of each patch size category was surveyed in each of the three geographic areas. Eleven additional patches (each <4 ha and located in the southern geographic area) were surveyed to investigate how size and spatial isolation of small patches affected occurrence and abundance of S. taenicauda. At all sites a standardised set of 22 habitat variables was collected, and the presence of other species of arboreal gecko was recorded. Key results: The species was located across patches of all sizes, including those as small as 1.11 ha. It was also located opportunistically in the matrix among patches and occurred in isolated trees within an urban area. The abundance of another commonly occurring arboreal gecko, Gehyra dubia (dubious dtella), was negatively correlated with S. taenicauda abundance in small patches. The most important habitat variable for S. taenicauda was average basal area of trees. As this increased, especially above 5.7 m2 ha-1, it was more likely to be present. When considering only the small patches, the main factors influencing presence and abundance of S. taenicauda were the average basal area of Callitris glaucophylla (white cypress) and grazing (negligible or absent). Conclusions: Strophurus taenicauda is a species that is tolerant of disturbance and can persist in fragmented habitat, provided the fragments have adequate cover of white cypress. Implications: The species appears to be resilient to the current level of CSG development within its geographic range.