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Australo-Pacific Petroica robins are known for their striking variability in sexual plumage coloration. Molecular studies in recent years have revised the taxonomy of species and subspecies boundaries across the southwest Pacific and New Guinea. However, these studies have not been able to resolve phylogenetic relationships within Petroica owing to limited sampling of the nuclear genome. Here, we sequence five nuclear introns across all species for which fresh tissue was available. Nuclear loci offer support for major geographic lineages that were first inferred from mtDNA. We find almost no shared nuclear alleles between currently recognized species within the New Zealand and Australian lineages, whereas the Pacific robin radiation has many shared alleles. Multilocus coalescent species trees based on nuclear loci support a sister relationship between the Australian lineage and the Pacific robin radiation-a node that is poorly supported by mtDNA. We also find discordance in support for a sister relationship between the similarly plumaged Rose Robin (P. rosea) and Pink Robin (P. rodinogaster). Our nuclear data complement previous mtDNA studies in suggesting that the phenotypically cryptic eastern and western populations of Australia's Scarlet Robin (P. boodang) are genetically distinct lineages at the early stages of divergence and speciation.

Complex spatial and temporal phylogenetic patterns have emerged among Pacific Island radiations and their Australian and New Guinean congeners. We explore the diversification of Australo-Pacific Pe...

Artificial retreats or refuges (ARs) provide a useful method for sampling lizards and a possible means of restoring habitat to aid population persistence. Previous research suggests that preferences for ARs may vary among species and between different designs. To test these ideas further, we examined the influence of thermal and structural characteristics on use of three types of ARs by the nocturnal common gecko (Hoplodactylus maculatus) and diurnal McCann's skink (Oligosoma maccanni), two lizards endemic to New Zealand. The field study confirmed that the three ARs (triple-layered Onduline, triple-layered iron, solid concrete) differed in retreat-site temperatures provided during each of three seasons (winter, spring and summer). In their top spaces, Onduline ARs were the warmest by day, coolest by night, and thus displayed the largest diel variations in temperature. In the laboratory, common geckos showed a significant preference for Onduline whether ARs were exposed to a radiant overhead heat source or not, whereas skinks did not display any preference among the three types of ARs regardless of heating. The three types of ARs provided field temperatures within the thermal preference range of both species (data obtained from the literature) but only for the top spaces of the ARs and only during summer. Onduline was the only AR to consistently provide the temperatures preferred by pregnant females. Although this study suggests that structural properties alone may be sufficient to explain the preference of geckos for triple-layered Onduline stacks, it does not eliminate the possibility that attractive thermal properties also contribute. Long-term studies are needed to test the effects of artificial refuge supplementation on reptiles, and on their predators and competitors.