Eastern blue-tongue lizards (Tiliqua scincoides) are kept in zoos and increasingly commonly as exotic pets, but little is known about improving their welfare by enrichment of their environment. Using nine animals kept individually in cages provided with a brick for basking and a pipe for hiding, we initially investigated enriching their environment with mealworms, either scattered on the floor or inserted into a foodball. The mealworms increased the time that the lizards spent feeding on both their ration and the mealworms and increased liveweight gain. Scattering the mealworms on the floor of their cages increased the time taken to eat them, compared with taking them from the foodball. Mealworms also reduced the time that the lizards spent hiding. Second, using eight individually housed lizards and replacing the pipe with a log which could be used both for basking and hiding, we investigated whether increasing the size of their enclosure and its temperature affected their behaviour, in a two-factor changeover design with two-week periods. When lizards were moved from small to large enclosures, they greatly increased the time that they spent walking on the first day, and they walked longer and further for the rest of the period. Lizards in big enclosures also spent more time hiding in the log and less time inactive on the log or the brick. Lizards in hot enclosures spent more time basking on the log and less time hiding in it, which would be valuable for display animals. The benefit of enriching the captive environment of Eastern blue-tongue lizards by scattering mealworms in their cage may depend on the effect on the lizards’ weight and the cage's conditions, as captive lizards often become obese, and inactivity and weight loss are normal in their natural habitat during the dry season. Increasing the size of enclosures increases walking activity and reduces weight gain, which similarly will have variable effects on welfare depending on the impact on their bodyweight. Lizards in large enclosures have an increased propensity to hide so it is important that opportunities for this are provided.

Host–parasite co-evolutionary studies can shed light on diversity and the processes that shape it. Molecular methods have proven to be an indispensable tool in this task, often uncovering unseen diversity. This study used two nuclear markers (18S rRNA and 28S rRNA) and one mitochondrial (cytochrome oxidase subunit I) marker to investigate the diversity of nematodes of the family Pharyngodonidae parasitizing New Zealand (NZ) lizards (lygosomine skinks and diplodactylid geckos) and to explore their co-evolutionary history. A Bayesian approach was used to infer phylogenetic relationships of the parasitic nematodes. Analyses revealed that nematodes parasitizing skinks, currently classified as Skrjabinodon, are more closely related to Spauligodon than to Skrjabinodon infecting NZ geckos. Genetic analyses also uncovered previously undetected diversity within NZ gecko nematodes and provided evidence for several provisionally cryptic species. We also examined the level of host–parasite phylogenetic congruence using a global-fit approach. Significant congruence was detected between gecko-Skrjabinodon phylogenies, but our results indicated that strict co-speciation is not the main co-evolutionary process shaping the associations between NZ skinks and geckos and their parasitic nematodes. However, further sampling is required to fully resolve co-phylogenetic patterns of diversification in this host–parasite system.

As with many islands, Christmas Island in the Indian Ocean has suffered severe biodiversity loss. Its terrestrial lizard fauna comprised five native species, of which four were endemic. These were abundant until at least the late 1970s, but four species declined rapidly thereafter and were last reported in the wild between 2009 and 2013. In response to the decline, a captive breeding programme was established in August 2009. This attempt came too late for the Christmas Island forest skink Emoia nativitatis, whose last known individual died in captivity in 2014, and for the non-endemic coastal skink Emoia atrocostata. However, two captive populations are now established for Lister's gecko Lepidodactylus listeri and the blue-tailed skink Cryptoblepharus egeriae. The conservation future for these two species is challenging: reintroduction will not be possible until the main threats are identified and controlled.