Termitaria are an important refuge for reptiles in the Pilbara of Western Australia

In all, 154 of 158 above-ground termitaria deconstructed in the Pilbara of Western Australia contained at least one vertebrate, and there was a mean of 30.4 (s.e. = 2.03) vertebrates and 4.5 (s.e. = 0.17) species in each mound. There was a significant difference in the relative abundance of species found in the termitaria and the 64 species found in the adjacent area. Termitaria were mostly occupied by eight species: Gehyra pilbara (66.3% of captures), Heteronotia binoei (13.7% of captures), Furina ornata (6.9%), Antaresia stimsoni (3.3%), Cyclorana maini (3.0%), Gehyra variegata (1.5%), Suta punctata (1.3%) and Planigale sp. (0.9%). It is likely that F. ornata, A. stimsoni and S. punctata used termitaria as a diurnal refuge and also prey upon reptiles living in the mound. If other termitaria in the Pilbara support a similarly high number of vertebrates, then these mounds provide an environmentally significant microhabitat and vertebrate fauna inhabiting the mounds should be captured and relocated before the termitaria are cleared or isolated as a result of development.

Predicting impacts of global climate change on intraspecific genetic diversity benefits from realistic dispersal estimates

Global climates are rapidly changing, which for many species will require dispersal to higher altitudes and latitudes to maintain favourable conditions. Changes in distribution for less mobile species is likely to be associated with losses to genetic diversity, yet this cannot be quantified without understanding which parts of a species distribution will colonise favourable regions in the future. To address this we adopted a realistic estimate of dispersal with predicted changes in species distributions to estimate future levels of intraspecific genetic diversity. Using 740 geckos (Gehyra variegata) collected across their distribution in central and eastern inland Australia, we predict genetic loss within phylogenetically distinct units at both mtDNA and microsatellite markers between 2010 and 2070. We found that using a quantified and realistic estimate of dispersal resulted in significant declines to allelic richness (5.114 to 4.052), haplotype richness (7.215 to 4.589) and phylogenetic diversity (0.012 to 0.005) (P < 0.01). In comparison, predicted losses were substantially over- or underestimated when commonly applied dispersal scenarios were utilised. Using biologically relevant estimates of dispersal will help estimate losses of intraspecific genetic diversity following climate change impacts. This approach will provide critical information for the management of species in the near future.

Levels of dispersal and tail loss in an Australian gecko (Gehyra variegata) are associated with differences in forest structure

Corridors of natural habitat are often sought to maintain dispersal and gene flow among habitat patches. However, structural changes in natural habitat over space and time may influence connectivity. Here we investigate whether differences in forest structure and the frequency of potential retreat sites is associated with the genetic structure of a tree-dwelling Australian gecko (Gehyra variegata). We sampled 113 adult geckos from multiple state forest and adjacent reserve locations within the Pilliga forest, New South Wales, Australia. Individuals were genotyped at 14 microsatellite loci and levels of dispersal were inferred by the degree of genetic structuring observed in state forest and reserve. A greater proportion of dead trees and tree debris (features that are used as retreat sites by G. variegata) were present within the state forests than in the reserve locations (P < 0.05). This reduction in frequency of retreat sites in reserves was associated with significantly less genetic structuring of G. variegata, implying higher levels of dispersal. Tail loss was also significantly higher in G. variegata sampled in reserves than in the state forests. We conclude that dispersal characteristics in G. variegata are associated with structural changes to natural habitat and that this may influence rates of predation.

Molecular phylogeny of Australian Gehyra (Squamata: Gekkonidae) and taxonomic revision of Gehyra variegata in south-eastern Australia

We provide the first phylogenetic hypothesis for the Australian species of the gekkonid genus Gehyra, based on 1044bp of the mitochondrial ND2 gene. Species representing the Asian, Melanesian and Australian radiations are resolved as separate clades, indicating relative isolation and independence of each of these evolutionary lines. Within the Australian radiation, the arid zone species form a monophyletic subgroup distinct from the remaining species found in tropical and warm mesic habitats. Extensive chromosome variation and highly variable external morphology have made species recognition difficult within Gehyra, exacerbated by the likely presence of numerous undescribed cryptic species. Three species of Gehyra are currently recognized in the southeastern inland of Australia, G. variegata, G. montium and G. purpurascens. We re-describe a fourth species, G. lazelli, to include those populations long referred to informally as the 2n=44 chromosome ‘race’ of Gehyra variegata. Gehyra lazelli widely overlaps the distribution of G. variegata in South Australia and the southern inland of New South Wales, with no suggestion of intergradation in morphology, mitochondrial DNA, allozyme variation or karyotype.