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Continual climate change strongly influences temperature conditions worldwide, making ectothermic animals as suitable species for studying the potential impact of climate change on global biodiversity. However, the study of how lizards distributed at different latitudes respond to climate change at the transcriptome level is still insufficient. According to the Climatic Variability Hypothesis (CVH), the range of climate fluctuations experienced by terrestrial animals throughout the year increases with latitude, so individuals at higher latitudes should exhibit greater thermal plasticity to cope with fluctuating environments. Mitochondria, as the energy center of vertebrate cells, may indicate species' plasticity through the sensitivity of gene expression. In this study, we focused on the changes in transcript levels of liver mitochondrial protein-coding genes (PCGs) in skinks from the genus Plestiodon (P. capito and P. elegans) and the genus Scincella (S. modesta and S. reevesii) under low-temperature conditions of 8 °C, compared to the control group at 25 °C. Species within the same genus of skinks exhibit different latitudinal distribution patterns. We found that the two Plestiodon species, P. elegans and P. capito, employ a metabolic depression strategy (decreased transcript levels) to cope with low temperatures. In contrast, the two Scincella species show markedly different patterns: S. modesta exhibits significant increases in the transcript levels of six genes (metabolic compensation), while in S. reevesii, only two mitochondrial genes are downregulated (metabolic depression) compared to the control group. We also found that P. capito and S. modesta, which live at mid-to-high latitudes, exhibit stronger adaptive responses and plasticity at the mitochondrial gene level compared to P. elegans and S. reevesii, which live at lower latitudes. We suggest that this enhanced adaptability corresponds to more significant changes in a greater number of genes (plasticity genes). [ABSTRACT FROM AUTHOR]

Abstract Background New Zealand is home to over 120 native endemic species of skinks and geckos that radiated over the last 20–40 million years, likely driven by the exploitation of diverse habitats formed during the Miocene. The recent radiation of animal hosts may facilitate cross-species virus transmission, likely reflecting their close genetic relationships and therefore relatively low barriers for viruses to emerge in new hosts. Conversely, as animal hosts adapt to new niches, even within specific geographic locations, so too could their viruses. Consequently, animals that have niche-specialised following radiations may be expected to harbour genetically distinct viruses. Through a metatranscriptomic analysis of eight of New Zealand’s native skink and gecko species, as well as the only introduced lizard species, the rainbow skink (Lampropholis delicata), we aimed to reveal the diversity of viruses in these hosts and determine whether and how the radiation of skinks and geckos in New Zealand has impacted virus diversity and evolution. Results We identified a total of 15 novel reptilian viruses spanning 11 different viral families, across seven of the nine species sampled. Notably, we detected no viral host-switching among the native animals analysed, even between those sampled from the same geographic location. This is compatible with the idea that host speciation has likely resulted in isolated, niche-constrained viral populations that have prevented cross-species transmission. Using a protein structural similarity-based approach, we further identified a highly divergent bunya-like virus that potentially formed a new family within the Bunyavirales. Conclusions This study has broadened our understanding of reptilian viruses within New Zealand and illustrates how niche adaptation may limit viral-host interactions.

Exposure to increased temperatures during early development can lead to phenotypic plasticity in morphology, physiology, and behavior across a range of ectothermic animals. In addition, maternal effects are known to be important contributors to phenotypic variation in offspring. Whether the 2 factors interact to shape offspring morphology and behavior is rarely explored. This is critical because climate change is expected to impact both incubation temperature and maternal stress and resource allocation. Using a fully factorial design, and Bayesian multivariate mixed models, we explored how the manipulation of early thermal environment and yolk-quantity in eggs affected the morphology, performance, and antipredator behavior of 2 sympatric Australian skink species (Lampropholis delicata and L. guichenoti). We found that juveniles from the hot treatment were larger than those on the cold treatment in L. guichenoti but not L. delicata. Using repeated behavioral measures for individual lizards, we found an interaction between incubation temperature and maternal investment in performance, with running speed being affected in a species-specific way by the treatment. We predicted that changes in performance should influence antipredator responses. In support of this prediction, we found that maternal investment impacted antipredator behavior, with animals from the yolk-reduced and cold treatment resuming activity faster after a simulated predatory attack in L. delicata. However, the prediction was not supported in L. guichenoti. Our results highlight the importance of exploring the multifaceted role that environments play across generations to understand how different anthropogenic factors will impact wildlife in the future. [ABSTRACT FROM AUTHOR]

Context: Knowledge of species' distribution and habitat associations is fundamental for conservation planning and management, especially in the context of range-restricted taxa. The Critically Endangered Kaputar rock skink (Egernia roomi) is a high elevation species that is restricted to the Nandewar Ranges (New South Wales, Australia). The species was not formally recognised until 2019, with its distribution, ecology, and threats poorly known. Aims: To determine the geographical distribution of the Kaputar rock skink and explore its ecology and threats. Methods: We performed surveys throughout high elevation regions of Mount Kaputar National Park, targeting suitable habitat for the Kaputar rock skink (rock outcrops and plateaux). Species distributional modelling (SDM) was used to identify potentially suitable habitat outside of our search areas. Key results: We detected the species at all historical record sites and at 15 new sites, increasing the species' known area of occupancy (AOO) four-fold (from 8 km2 to 40 km2), and elevational range three-fold (from 1360–1480 m to 1147–1509 m). Conclusion: The AOO for the species now exceeds the IUCN Red List threshold for Critically Endangered, but falls within the range for Endangered under Criterion B. Our SDMs indicated that all predicted suitable habitat for the species falls within the region that we surveyed in this study. Implications: Our study provides valuable information on the geographic range of a threatened lizard species and evaluates the potential impact of large-scale fires on the persistence of the species. The Kaputar rock skink (Egernia roomi) was only formally recognised as a species in 2019, with little known about its distribution and ecology. Given its miniscule distribution, it was federally listed as Critically Endangered, despite no further formal survey work. Here, we use field surveys as well as species distributional modelling to ascertain the species'true range and its threats. [ABSTRACT FROM AUTHOR]

New World mabuyine skinks are a diverse radiation of morphologically cryptic lizards with unique reproductive biologies. Recent studies examining population-level data (morphological, ecological, and genomic) have uncovered novel biodiversity and phenotypes, including the description of dozens of new species and insights into the evolution of their highly complex placental structures. Beyond the potential for this diverse group to serve as a model for the evolution of viviparity in lizards, much of the taxonomic diversity is concentrated in regions experiencing increasing environmental instability from climate and anthropogenic change. Consequently, a better understanding of genome structure and diversity will be an important tool in the adaptive management and conservation of this group. Skinks endemic to Caribbean islands are particularly vulnerable to global change with several species already considered likely extinct and several remaining species either endangered or threatened. Combining PacBio long-read sequencing, Hi-C, and RNAseq data, here we present the first genomic resources for this group by describing new chromosome-level reference genomes for the Puerto Rican Skink Spondylurus nitidus and the Culebra Skink S. culebrae. Results indicate two high quality genomes, both ∼1.4 Gb, assembled nearly telomere to telomere with complete mitochondrion assembly and annotation. [ABSTRACT FROM AUTHOR]

Normal ophthalmic parameters of the blue-tongued skink (Tiliqua scincoides), one of the largest members of the skink family of lizards, have yet to be evaluated. The objective of this study was to establish baseline ophthalmic parameters for a captive population of 12 healthy, 1-yr-old blue-tongued skinks. Ophthalmic examination, corneal touch threshold, tear production including phenol red thread test (PRTT) and modified Schirmer tear test-2 (mSTT-2), horizontal palpebral fissure length (HPFL), rebound tonometry (TONOVET and TONOVET Plus), and bacterial and fungal cultures were performed. The blue-tongued skinks were all amenable to ocular diagnostic testing. Corneal touch threshold (mean ± SD) was 5.48 ± 0.81 cm. PRTT (mean ± SD) was 9.17 ± 6.62 mm/15 sec. mSTT-2 (mean ± SD) was 2.54 ± 2.72 mm/60 sec. HPFL (mean ± SD) was 6.96 ± 0.62 mm and was positively correlated with body weight. Intraocular pressure (IOP) assessed using TONOVET (mean ± SD) was 8.43± 1.51 mmHg, whereas IOP assessed using TONOVET Plus (mean ± SD) was 12.39± 1.54 mmHg. Differences in TONOVET and TONOVET Plus tonometry values were statistically significant (P < 0.0001), and TONOVET values were positively correlated with body weight. The most common bacterial species identified were Staphylococcus xylosus (10/12) and Staphylococcus sciuri (8/12). Fungal cultures were all negative. One animal had superficial corneal ulceration that resolved with treatment. Ophthalmic examination and testing is readily performed in blue-tongued skinks. These parameters may be useful for ocular assessment of this species in a clinical setting. [ABSTRACT FROM AUTHOR]

Continual climate change strongly influences temperature conditions worldwide, making ectothermic animals as suitable species for studying the potential impact of climate change on global biodiversity. However, the study of how lizards distributed at different latitudes respond to climate change at the transcriptome level is still insufficient. According to the Climatic Variability Hypothesis (CVH), the range of climate fluctuations experienced by terrestrial animals throughout the year increases with latitude, so individuals at higher latitudes should exhibit greater thermal plasticity to cope with fluctuating environments. Mitochondria, as the energy center of vertebrate cells, may indicate species’ plasticity through the sensitivity of gene expression. In this study, we focused on the changes in transcript levels of liver mitochondrial protein-coding genes (PCGs) in skinks from the genus Plestiodon (P. capito and P. elegans) and the genus Scincella (S. modesta and S. reevesii) under low-temperature conditions of 8 °C, compared to the control group at 25 °C. Species within the same genus of skinks exhibit different latitudinal distribution patterns. We found that the two Plestiodon species, P. elegans and P. capito, employ a metabolic depression strategy (decreased transcript levels) to cope with low temperatures. In contrast, the two Scincella species show markedly different patterns: S. modesta exhibits significant increases in the transcript levels of six genes (metabolic compensation), while in S. reevesii, only two mitochondrial genes are downregulated (metabolic depression) compared to the control group. We also found that P. capito and S. modesta, which live at mid-to-high latitudes, exhibit stronger adaptive responses and plasticity at the mitochondrial gene level compared to P. elegans and S. reevesii, which live at lower latitudes. We suggest that this enhanced adaptability corresponds to more significant changes in a greater number of genes (plasticity genes).

Documenting the diet of organisms that have been introduced and naturalised outside their native range is a fundamental component of understanding their trophic interrelations in the receiving environment, and for developing holistic management practices for introduced species' predation impacts in an ecosystem. We describe two accounts of terrestrial reptiles in the diet of an introduced fish, rainbow trout Oncorhynchus mykiss in southern NSW, Australia. Our observations from the Southern Hemisphere together with recently published records from the Northern Hemisphere (e.g. USA, France and Italy) represent the presence of reptiles in the diet of O. mykiss across a broad geographical range and highlight a potential additional consideration of introduced salmonids and their impacts on terrestrial species. [ABSTRACT FROM AUTHOR]

Invasive mammalian predators are a global biodiversity problem, particularly in archipelagos in which native fauna evolved in isolation from mammals. Landscape scale management of selected invasive mammalian predators is occurring across Aotearoa New Zealand to protect vulnerable forest birds and bats. In temperate southern beech forests, both predator irruptions and the timing of predator control is driven by mast seeding of beech trees. Relationships between predators targeted in this control, other invasive mammalian predators and other native taxa, particularly lizards and invertebrates, are poorly understood. We monitored southern grass skinks in the Eglinton Valley, Fiordland from 2009 to 2020 alongside monitoring of predators (stoats, rats and mice) in a system where predator control occurred in response to mast seeding. We evaluated relationships between skink abundance and abundance of rats (targeted in predator control operations) and mice (which also prey on small vertebrates like lizards, but are not controlled). Skink abundance declined over time and was negatively correlated with mouse abundance, but not correlated with rat abundance. Current landscape predator control to protect forest birds and bats is likely insufficient to protect ground-dwelling lizards, and may actually be detrimental to lizard populations if controlling the other predators contributes to a mesopredator release of mice. Mice are significant predators of a range of small vertebrates and large invertebrates, yet research into the sustainable suppression of mice to benefit vulnerable native populations is lacking. We strongly advocate for such research in order to deliver conservation management that benefits the full suite of biodiversity. [ABSTRACT FROM AUTHOR]

Conservation management cannot proceed in the absence of the basic ecological data necessary to develop conservation strategies for a species. Species considered Data Deficient and possibly extinct are poorly known, and are often overlooked in conservation planning. This is despite a growing body of evidence indicating that Data Deficient species are more likely to be threatened by extinction compared to well‐studied taxa. Hence, there is an immediate need to resolve data deficiency, and to search for species that are possibly extinct. Here, we conducted the first systematic search for a Data Deficient Australian skink, Lampropholis elongata (long sunskink), which prior to our study, had not been seen for approximately 9 years. A combination of pitfall trapping and active searches was used in attempt to detect the species. We rediscovered L. elongata at four sites within its known distribution on the southern edge of the New England Tablelands Bioregion in New South Wales, Australia. Our findings suggest that the species can be detected relatively easily using active survey methods, especially by inspecting tussock bases. We further highlight that areas of high canopy openness and high cover of Poa sieberiana (grey tussock‐grass) appear to be key habitat for the species. [ABSTRACT FROM AUTHOR]

The White-necked Puffbird (Notharchus hyperrhynchus) consumes mainly large insects, and may take small vertebrates, but this has rarely been documented. We document predation by a Puffbird on a lizard in the tropical humid rainforest of Corcovado National Park, Costa Rica. On 5 December 2022, at 17:25 h we observed a Whitenecked Puffbird perched at 7 m height that flew to a branch at 6 m high in an adjacent tree and captured a Central American Mabuya (Marisora unimarginata). The Puffbird returned to its perch, where we observed for 4 mins as the Puffbird hit the skink against the surface, until it was dead and swallowed it whole. Our observation provides the first documented evidence of predation on a lizard by the White-necked Puffbird in tropical forest. This is important given that populations of the White-necked Puffbird are declining, and the Central America Mabuya has a restricted distribution. Hence, our observation provides species-level information on predator-prey interactions that may fill knowledge gaps for management decisions. [ABSTRACT FROM AUTHOR]

New Zealand's endemic reptile fauna is highly threatened and pathogens causing infectious diseases may be a significant risk to already endangered species. Here, we investigate Cryptosporidium infection in captive endemic New Zealand reptiles. We found two mammal-related Cryptosporidium species (C. hominis and C. parvum) and six subtypes from three gp60 families (Ib, Ig and IIa) in 12 individuals of captive endemic Tuatara, Otago and Grand skinks, and Jewelled and Rough geckos. Cryptosporidium serpentis was identified in two Jewelled geckos using 18S. In New Zealand, C. hominis and C. parvum are associated with infections in humans and introduced domestic animals but have also been recently found in wildlife. Our finding of Cryptosporidium infection in endemic reptiles can help inform strategies to monitor the conservation of species and manage potential introductions of pathogens to in-situ and ex-situ populations. [ABSTRACT FROM AUTHOR]

Predator-free sanctuaries can assist the conservation of multiple endemic species, but quantitative evidence of these benefits is often lacking, especially for herpetofauna. We measured population responses of three common lizard species (schist geckos, Woodworthia 'Central Otago'; McCann's skinks, Oligosoma maccanni; and southern grass skinks, O. aff. polychroma Clade 5) 1 year before and 5 years after mammalian predators were removed inside a mammal-proof fence in a dry grass/shrubland habitat with abundant schist rock in Central Otago, New Zealand. Gecko counts in 25 artificial retreats (ARs) along replicated, 250-m long transects inside the fence increased from 5.2 to 17.7 per transect, compared with 3.3 to 5.4 per transect outside the fence where predators were present. This indicates a doubling of counts inside the fence when changes outside the fence are accounted for. The number of skinks seen along these transects increased from 1.3 to 2.3 per transect without predators, compared with 0.6 to 0.4 with predators. Lizard tracking tunnel indices (recorded only after predators were removed) were significantly higher without predators (62% geckos, 42% skinks) than where predators were present (12% geckos, 2% skinks). Tail loss in geckos was significantly higher where predators were present (24%) than where they were absent (1%). These data suggest that common lizard species are being suppressed to a significant degree by mammalian predators and demonstrate the potential for their recovery where predators are removed. [ABSTRACT FROM AUTHOR]

The main drivers of lizard population declines in Aotearoa New Zealand are habitat loss and introduced predators. Therefore, habitat enhancement could be useful for mitigating declines, but there is little information on how Aotearoa-endemic lizards respond to these interventions. We examined whether novel habitats created by ten c. 375 m3 constructed rock piles would be used by McCann's skinks (Oligosoma maccani), southern grass skinks (O. aff. polychroma Clade 5), and kōrero geckos (Woodworthia "Otago/Southland large"). The rock piles and their immediate edges were surveyed 22 times between four months and 2.4 years post-construction, resulting in 228 sightings of McCann's skinks on all ten piles, 20 sightings of southern grass skinks on six piles, and two sightings of kōrero geckos on two piles. Estimated abundance of McCann's skinks increased over time, and neonates were observed. These observations indicate that rock pile construction could create habitats for McCann's skinks, but further inference is limited. We recommend that future mitigation programs quantify how habitat construction affects lizard populations and suggest methods for achieving this. [ABSTRACT FROM AUTHOR]

The capture of animals in live traps poses inherent risks of heat stress and mortality to trapped individuals. Despite a long history of pitfall trap use in New Zealand for monitoring small lizards, the design of traps and their covers often varies; however, the effects that this has on the internal temperature of the traps is unknown. Poor trap design may increase the risk of stress and mortality if internal temperatures exceed thermal limits. We tested the influence of three aspects of trap design (cover material, cover colour, and internal trap size) on the maximum and mean internal trap temperatures at Kaitorete Spit, New Zealand. Temperatures were recorded with dataloggers across 24 days during midsummer (December 2020 to January 2021). Internal temperatures reached a maximum of 38.2 °C (on a day with a maximum air temperature around 31 °C). Those trap temperatures are above predicted harmful thermal limits of some New Zealand gecko species and levels that induce avoidance behaviour in some skinks. Maximum temperatures were lower under plywood covers than those made of plastic or Onduline, brown covers than black, and in 4 L traps rather than 1 L. The best trap design had thermal maxima 3.9 °C lower than the worst design, averaging 4.9 °C above air maximum temperatures in the best design compared with 8.6 °C above for the worst. As climate change increases temperatures in some areas, the risk of heat stress and mortality rises for lizards constrained in pitfall traps. We recommend the use of plywood covers and larger internal trap sizes to reduce this risk. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation are likely to seriously impact parasites, a less studied but critical component of ecosystems, yet we lack long‐term experimental evidence. Parasites structure communities, increase connectivity in food webs, and account for a large proportion of an ecosystem's total biomass. Food web models predict that parasites with multiple obligate hosts are at greater risk of extinction because the local extinction, or reduction in abundance, of any host will result in a life‐cycle bottleneck for the parasite. We examine the response of a parasite and its multiple hosts to forest fragmentation over 26 years in the Wog Wog Habitat Fragmentation Experiment in southeastern Australia. The parasite is the nematode Hedruris wogwogensis, its intermediate host is the amphipod, Arcitalitrus sylvaticus, and its definitive host is the skink, Lampropholis guichenoti. In the first decade after fragmentation, nematodes completely disappeared from the matrix (plantation forestry) and all but disappeared from their definitive host (skinks) in fragments, and by the third decade after fragmentation had not appreciably recovered anywhere in the fragmented landscape compared to continuous forest. The low prevalence of the nematode in the fragmented landscape was associated with the low abundance of one or the other host in different decades: low abundance of the intermediate host (amphipod) in the first decade and low abundance of the definitive host (skink) in the third decade. In turn, the low abundance of each host was associated with changes to the abiotic environment over time due largely to the dynamically changing matrix as the plantation trees grew. Our study provides rare long‐term experimental evidence of how disturbance can cause local extinction in parasites with life cycles dependent on more than one host species through population bottlenecks at any life stage. Mismatches in the abundance of multiple hosts over time are likely to be common following disturbance, thus causing parasites with complex life cycles to be particularly susceptible to habitat fragmentation and other disturbances. The integrity of food webs, communities, and ecosystems in fragmented landscapes may be more compromised than presently appreciated due to the sensitivity of parasites to habitat fragmentation. [ABSTRACT FROM AUTHOR]

Introduction: The eastern blue‐tongued skink (Tiliqua scincoides scincoides), native to eastern Australia, is commonly kept as both a pet and for breeding. As a sexually monomorphic species, it is important to develop reliable techniques for sex identification, both for breeding and health purposes. Numerous techniques have been developed for the identification of sex in other reptile species but, other than possibly morphometric analysis, none have proven to be reliable in this species. Two techniques showing promise are contrast radiography of the hemepenes/hemeclitores, and morphometrical analysis. This study looks at both techniques and compares them for accuracy. Methods and Materials: Twenty captive eastern blue‐tongued skinks (of known sex) were sedated, contrast radiography of their hemepenes /hemeclitores was performed, and physical measurements were taken for morphometric analysis. The radiographs were examined by a panel of three researchers (blinded to the known sex) to identify sex. The morphometric data were statistically analysed, following a previously published methodology, and the individual sex identified. Again, the researchers were blinded to the known sex. Results: The contrast radiography technique was 100% accurate in correctly identifying the sex of all the skinks. Morphometric analysis was, by contrast, only 70% accurate. Conclusion and Clinical Relevance: Physical differences between wild and captive skinks, as well as different environmental and nutritional factors, may have contributed to the lower accuracy of morphometric analysis in identifying the sex of eastern blue‐tongued skinks. While contrast radiography was more accurate, the need for specialised equipment may render this technique impractical for field researchers, but more suitable for owned animals. More research is needed to assess the impact of captivity on eastern blue‐tongued skinks' physical morphometrics. [ABSTRACT FROM AUTHOR]

The diet in skinks is known mainly for extra-European species, especially from Australian ones, where these lizards are represented by a great number of species, while, in comparison, data for species from other continents are scarce. The three-toed skink, Chalcides chalcides, is found in a restricted part of northern Africa and in Italy, where it is distributed almost uniformly throughout the peninsula and on the major islands. Although it is well studied for aspects such as morphology and ecology, data concerning trophic preferences are scarce, and available only for the populations of south-central Italy. In this note we report preliminary data about the diet of an Apennine population of the three-toed skink, Chalcides chalcides, at the northern boundary of its distribution area. Faecal contents from 20 individuals were collected in June 2015, obtaining an overall sample of 48 prey items. Araneae constituted the most preyed taxon (over 40%), followed by Hemiptera (35,4%) and other prey taxa (Hymenoptera, Coleoptera, and Dermaptera) in much lower percentages. We found no differences between smaller/younger and larger/older individuals in consumed preys. As well as confirming the general trophic predilection of this skink for spiders, we also found some interesting differences in preyed items with studied populations of south-central Italy. [ABSTRACT FROM AUTHOR]

The diet in skinks is known mainly for extra-European species, especially from Australian ones, where these lizards are represented by a great number of species, while, in comparison, data for species from other continents are scarce. The three-toed skink, Chalcides chalcides, is found in a restricted part of northern Africa and in Italy, where it is distributed almost uniformly throughout the peninsula and on the major islands. Although it is well studied for aspects such as morphology and ecology, data concerning trophic preferences are scarce, and available only for the populations of south-central Italy. In this note we report preliminary data about the diet of an Apennine population of the three-toed skink, Chalcides chalcides, at the northern boundary of its distribution area. Faecal contents from 20 individuals were collected in June 2015, obtaining an overall sample of 48 prey items. Araneae constituted the most preyed taxon (over 40%), followed by Hemiptera (35,4%) and other prey taxa (Hymenoptera, Coleoptera, and Dermaptera) in much lower percentages. We found no differences between smaller/younger and larger/older individuals in consumed preys. As well as confirming the general trophic predilection of this skink for spiders, we also found some interesting differences in preyed items with studied populations of south-central Italy.

Aim: Geographic range size varies greatly across species. Climate, along with aspects of a species' biology, may influence its spatial extent. We investigate intrinsic and extrinsic predictors of range size in Australian skinks. We predicted that larger body size, longer limbs, and larger clutch sizes would be associated with larger ranges, and that ranges would be larger in colder, more arid, and more seasonal climates. Location: Mainland Australia. Taxon: Skinks (Scincidae). Methods: We test for climatic and geographic correlates of range size of Australian skink species (417 of 462 described species), as well as investigate the effects of body size and clutch size (259 species). We compare detailed morphological measurements of 1,324 specimens across nine pairs of widespread and narrow‐ranged congeneric species to investigate the roles of intrinsic (body size, clutch size, morphology) and extrinsic (mean temperature and precipitation) factors in determining range size. Results: In the broader analysis, large range sizes were associated with the presence of fully developed limbs, low precipitation seasonality, high temperatures, and high precipitation. Ranges of species traversing the Great Dividing Range are larger by an order of magnitude than those east of the range, with western ranges being intermediate. Affinity to specific biomes explained less variation than climatic variables. For the nine species pairs, wide‐ranging species share similar morphologies and clutch sizes with overlapping narrow‐ranging congeners, but generally inhabit more arid regions. Main conclusions: We found several extrinsic, but few intrinsic, factors were correlated with range size. The narrow mesic belts in Australia compared with the extensive expanse of arid and semi‐arid regions may explain why desert species have larger ranges. This interpretation agrees with the notion that the size of the domain, here a climatic domain rather than a physical one, may exert strong influence on species' range sizes. [ABSTRACT FROM AUTHOR]

We describe a 226 km range extension for the known distribution of the Western Soil-Crevice Skink Proablepharus reginae in Western Australia. This record from Cape Range National Park is the first for this species on the North West Cape and within the Cape Range IBRA sub-region and marks the most westerly record of P. reginae for mainland Australia. This finding raises the terrestrial reptile species richness for the Cape Range peninsula to 90. Previous surveys in this area failed to detect P. reginae, which demonstrates the value of repeated surveys in documenting species richness in remote locations. Furthermore, we provide morphological and ecological data and discuss this record in the contexts of geographic variation and the high number of isolated reptile populations and endemism seen on the Cape Range peninsula. [ABSTRACT FROM AUTHOR]

The purpose of the present application, under Articles 74.1.1 and 81.1 of the Code, is to maintain consistent usage of the commonly used name Emoia nigra (Hombron & Jacquinot, 1853) by setting aside a lectotype designation for Gongylus (Eumeces) freycinetiDuméril & Bibron, 1839 by Wells & Wellington in 1985 in favour of a later lectotype designation by Brown in 1991. [ABSTRACT FROM AUTHOR]

Vertebrates introduced in non-native habitats have contributed to several extinctions in the modern era, with direct effects mainly over birds, mammals and reptiles on islands. Fernando de Noronha Archipelago, in tropical Atlantic Ocean, is a World Heritage natural site, holding the most diverse breeding seabird community off Brazil, in addition to endemic landbirds and reptiles. It also holds invasive black rats (Rattus rattus), tegu lizards (Salvator merianae) and feral cats (Felis catus), among the 26 exotic species reported in the archipelago, all of which are species with potentially high impact upon native fauna. Aiming to assess the role of exotic vertebrates on the fauna, we investigated their diets through stomach content and scat analysis, and stable isotope analysis (SIA) followed by isotopic mixing models. The main food items for tegu lizards were fruits, with relative importance (Prey-specific Index of Relative Importance – %PSIRI) of 41.3%, and the endemic Noronha skink (Trachylepis atlantica; 19.6%) and for black rats was Noronha skink (30.3%). The diet of feral cats was composed by rodents (31.6%), birds (28.6%) and Noronha skink (18.8%). SIA and Bayesian mixing models provided evidences that invasive species use marine matter to synthesize tissues, probably derived directly or indirectly from seabird colonies. This study demonstrated that exotic species feed on other exotic, as well as endemic species. The most heavily impacted species was the endemic Noronha skink. We demonstrated the predation pressure of exotic fauna upon endemic vertebrates, and strongly recommend the implementation of an invasive species control and eradication plan.

Abstract Sexual size dimorphism (SSD) is widespread in animals, especially in lizards (Reptilia: Squamata), and is driven by fecundity selection, male–male competition, or other adaptive hypotheses. However, these selective pressures may vary through different life history periods; thus, it is essential to assess the relationship between growth and SSD. In this study, we tracked SSD dynamics between a “fading‐tail color skink” (blue tail skink whose tail is only blue during its juvenile stage: Plestiodon elegans) and a “nonfade color” tail skink (retains a blue tail throughout life: Plestiodon quadrilineatus) under a controlled experimental environment. We fitted growth curves of morphological traits (body mass, SVL, and TL) using three growth models (Logistic, Gompertz, and von Bertalanffy). We found that both skinks have male‐biased SSD as adults. Body mass has a higher goodness of fit (as represented by very high R2 values) using the von Bertalanffy model than the other two models. In contrast, SVL and TL for both skinks had higher goodness of fit when using the Gompertz model. Two lizards displayed divergent life history tactics: P. elegans grows faster, matures earlier (at 65 weeks), and presents an allometric growth rate, whereas P. quadrilineatus grows slower, matures later (at 106 weeks), and presents an isometric growth rate. Our findings imply that species‐ and sex‐specific trade‐offs in the allocation of energy to growth and reproduction may cause the growth patterns to diverge, ultimately resulting in the dissimilar patterns of SSD.

Context: In montane systems, closely related species tend to segregate spatially along elevational gradients. The role of biotic interactions, relative to species physiological requirements, in maintaining these distribution patterns is an important question in spatial ecology. Theory suggests that the role of interspecific competition can be significant in the maintenance of elevation replacement distributions. Despite this, there has been limited work investigating factors beyond thermophysiology in determining ranges in temperate montane species. Objectives and methods: We investigated agonistic (i.e. aggressive) behaviour in response to a simulated intruder (conspecific versus heterospecific 3D printed models) in two sister species of temperate montane lizard, Liopholis guthega and L. montana, from south-eastern Australia. The two species have similar thermal tolerances at an area of distributional overlap between 1600 and 1700 m above sea level, above which L. montana is replaced by the high elevation specialist L. guthega. Results: We found that response to intruder stimuli differed between the two species, with the high elevation L. guthega actively biting both conspecific and heterospecific models, whereas the lower elevation L. montana, never attacked either model type. Our findings provide evidence of asymmetric agonistic response in the two montane reptile species. Conclusions: These findings have important implications for understanding how biological interactions and behaviour, in addition to thermo-physiological data, might mediate landscape scale distribution patterns both now and as environments change in the future. More broadly, our results are not consistent with the widespread idea that low elevation species will inevitably 'push' higher elevation species out, as global warming erodes species' thermal envelopes. [ABSTRACT FROM AUTHOR]

Behavioral syndromes, when individuals within a population express consistent behavioral differences across time and context, are widespread in animal taxa. For many species, males and females experience different selective pressures after maturation, resulting in the divergence of life‐history and behavioral traits. However, the potential for sex‐specific differences in individual behaviors and behavioral syndromes has rarely been assessed. Here, we tested for sex‐specific differences in behavior (activity, exploration, sociability) and personality in the southern rainforest sunskink, Lampropholis similis. We found that most behaviors in L. similis did not differ between sexes, the exception being sociality which was higher in females than males. In terms of consistency among behaviors, activity and exploration, but not sociability, were repeatable, and there were no sex‐specific differences in repeatability of behavioral traits. Although a behavioral syndrome among these three traits is present in a congener (L. delicata), we found no evidence for such a syndrome in either sex of L. similis. Our study is consistent with the results of studies on other Lampropholis skinks that have found only limited sexual differences in behavior. More broadly, our study demonstrates there can be considerable differences in the presence or absence of behavioral syndromes in closely related species. [ABSTRACT FROM AUTHOR]

The rapid changes in altitude, and associated habitat, of mountain ecosystems make them ideal natural laboratories for testing the effect of environmental heterogeneity on species assemblage. Our understanding of the sensitivity of Australian reptiles to elevational clines is limited. We examined lizard distribution across three elevation zones (montane, subalpine and alpine), spanning from 900 to 1840 m above sea level, in the Australian alps. We aimed to examine how elevation influences species diversity and abundance, and ectoparasite load, and whether species alter their habitat use amongst different elevational zones. Active searches were conducted across the elevation zones to identify lizard community structure (at least 16 species) across elevational zones, along with skink habitat preferences and the ectoparasite load. Skink diversity and abundance were negatively correlated with increased elevation. The alpine zone had significantly lower diversity and abundance of skinks. Habitat use differed amongst both elevations and species. Ectoparasite prevalence was also significantly diminished in the alpine zone. Ectoparasites only infected a subset of the skink community, with ectoparasite load increasing as the active season progressed. This study provides evidence of the complex interplay between elevation and species diversity, as well as the differences in ectoparasite pressure along elevational gradients in the Australian alps. [ABSTRACT FROM AUTHOR]

We here describe the first Neogene record of the squamate clade Mabuyidae. Although this clade has a cosmopolitan distribution today, no pre‐Quaternary fossil record of these reptiles has so far been documented. The material comes from the locality Solnechnodolsk (Russia) and is dated to the late Miocene (MN 13). Although it comprises only jaw elements, it constitutes the first evidence of the occurrence of fossil skinks around the area of the Black Sea. The material is identical to Heremites vittatus, showing the existence of this lineage as early as the late Miocene. Thus, it may be used as a potential calibration point for further studies. The comparative anatomy of the structures of lower jaw in selected scincomorph taxa with a special reference to Mabuya group is presented. The closure of the Meckelian canal is the condition at the basal node of the clade Sphenomorphidae + Eugongylidae + Egerniidae + Mabuyidea, whereas the closed canal in Acontias (Acontidae) evolved independently. However, Sphenomorphidae (Asymblepharus and Scincella) + Eugongylidae (Ablepharus) retain a large anterior opening of the Meckelian canal, whereas only a small opening characterizes the basal node of Egerniidae and Mabuyidae, except for H. vittatus and H. septemtaeniatus. The closure of the Meckelian canal in these two taxa is less well developed in comparison with other mabuyid skinks. Thus, a heterochronic pedomorphic process might have played a role in the evolution of these skinks. The Meckelian canal condition supports the monophyly of Heremites. [ABSTRACT FROM AUTHOR]

A specimen of the Triodia Earless Skink Hemiergis millewae was discovered on the Barrier Range of far-western New South Wales (NSW). This observation is significant because it constitutes the first record of the species in NSW and the Broken Hill Complex bioregion, extending the species' range 140 km north-east of the nearest known population in South Australia. Suitable spinifex habitat for H. millewae is highly isolated and small in extent on the Barrier Range, and the species may qualify for listing as a threatened species in NSW. I discuss the cause of apparent disjunctions in the species' distribution and highlight the need for additional survey effort. [ABSTRACT FROM AUTHOR]

The description of Rurk’s Cat Skink Ristella rurkii is expanded herein based on recent field sightings and a voucher specimen. Three individuals comprising an adult male, an adult female, and a juvenile were encountered in Kodaikanal, Palni Hills of the southern Western Ghats. Morphological and ecological notes on the voucher specimen and these live sightings are elaborated to enrich the current knowledge on this little-known species. This species is also illustrated in life herein for the first time. The current report forms the rediscovery of this species after nearly 90 years and after a lapse of 175 years since its original description. A review of its past distribution records is compiled and further surveys are recommended to revise the geographic range and conservation status of this Data Deficient species.

Abstract Background The application of target capture with next-generation sequencing now enables phylogenomic analyses of rapidly radiating clades of species. But such analyses are complicated by extensive incomplete lineage sorting, demanding the use of methods that consider this process explicitly, such as the multispecies coalescent (MSC) model. However, the MSC makes strong assumptions about divergence history and population structure, and when using the full Bayesian implementation, current computational limits mean that relatively few loci and samples can be analysed for even modest sized radiations. We explore these issues through analyses of an extensive (> 1000 loci) dataset for the Australian rainbow skinks. This group consists of 3 genera and 41 described species, which likely diversified rapidly in Australia during the mid-late Miocene to occupy rainforest, woodland, and rocky habitats with corresponding diversity of morphology and breeding colouration. Previous phylogenetic analyses of this group have revealed short inter-nodes and high discordance among loci, limiting the resolution of inferred trees. A further complication is that many species have deep phylogeographic structure – this poses the question of how to sample individuals within species for analyses using the MSC. Results Phylogenies obtained using concatenation and summary coalescent species tree approaches to the full dataset are well resolved with generally consistent topology, including for previously intractable relationships near the base of the clade. As expected, branch lengths at the tips are substantially overestimated using concatenation. Comparisons of different strategies for sampling haplotypes for full Bayesian MSC analyses (for one clade and using smaller sets of loci) revealed, unexpectedly, that combining haplotypes across divergent phylogeographic lineages yielded consistent species trees. Conclusions This study of more than 1000 loci provides a strongly-supported estimate of the phylogeny of the Australian rainbow skinks, which will inform future research on the evolution and taxonomy of this group. Our analyses suggest that species tree estimation with the MSC can be quite robust to violation of the assumption that the individuals representing a taxon are sampled from a panmictic population.

Trade-offs are thought to be important in constraining evolutionary divergence as they may limit phenotypic diversification. The cranial system plays a vital role in many functions including defensive, territorial, predatory and feeding behaviours in addition to housing the brain and sensory systems. Consequently, the morphology of the cranial system is affected by a combination of selective pressures that may induce functional trade-offs. Limbless, head-first burrowers are thought to be constrained in their cranial morphology as narrow heads may provide a functional advantage for burrowing. However, having a wide and large head is likely beneficial in terms of bite performance. We used 15 skink species to test for the existence of trade-offs between maximal push and bite forces, and explored the patterns of covariation between external head and body morphology and performance. Our data show that there is no evidence of a trade-off between bite and burrowing in terms of maximal force. Species that generate high push forces also generate high bite forces. Our data also show that overall head size covaries with both performance traits. However, future studies exploring trade-offs between force and speed or the energetic cost of burrowing may reveal other trade-offs. [ABSTRACT FROM AUTHOR]

Many reptiles occur in landscapes that are prone to fire, yet limited information is available on the cues these species use to detect approaching fires or their immediate and preemptive behavioral responses to fire stimuli. Here, we describe the behavioral response of ten captive sleepy lizards (Tiliqua rugosa) that were inadvertently exposed to light smoke. Proportionately, significantly more individuals that were exposed to smoke exhibited increased activity, including swift pacing, repeated escape behaviors, and rapid olfactory-related tongue-flicking than those that were not exposed, which did not exhibit any such changes in activity or behaviors. Additionally, of 14 reptile species housed in the smoke-affected area, T. rugosa was the only species to exhibit a noticeable behavioral response. Since there were no visible flames, sounds of fire, reductions in light levels or visibility, or increases in temperature, these observations suggest that T. rugosa detects smoke through olfaction. Moreover, because most individuals were captive-born and, therefore, naïve to smoke or fire, this response likely represents an adaptive innate behavioral response of the species. We discuss these findings in the light of fire avoidance behavior in Tiliqua and reptiles in general. [ABSTRACT FROM AUTHOR]

The Liu’s skink, Plestiodon liui, is endemic to China. In this study, a nearly complete mitochondrial genome (mitogenome) (17,643 bp in length) of P. liui from Junzhang Mountain, Wuxi, Jiangsu province, China, was determined by next-generation sequencing. Similar to the typical mtDNA of vertebrates, it contained two ribosomal RNA genes, 13 protein-coding genes (PCGs), 22 transfer RNA genes, and one control region (CR). With exception to the CR, all of the 37 genes were completely recovered. The PCGs were used to perform Bayesian phylogenetic analyses together with other scincid lizards with mitogenome data in GenBank. The resulting phylogenetic tree supported the monophyly of the P. capito group, and suggested that P. liui is the sister taxon to P. capito plus P. tunganus. The mitogenome of P. liui will provide fundamental data for the exploration of the mitogenome evolution in skinks.

Predator-based selection has resulted in the repeated evolution of a variety of antipredator traits. Despite the effectiveness of these traits, some species experience shifts or even complete loss of antipredator traits during development. The evolutionary forces that favour such a transition are poorly understood. We sought to comprehend the role of predator-based selection and organismal factors underlying developmental loss of antipredator traits by focusing on decoy coloration in skink lizards. To this end, we studied the ontogenetic loss of decoy tail coloration in three Nearctic skink species. We performed natural history collection surveys and clay-model studies on predation to determine the organismal determinants of decoy coloration (body size and energy content of the tail) and predation based upon size and decoy coloration. We found that decoy coloration was lost during development at a similar size in all three species. Although predation rates on juvenile models were similar for both uniform brown and decoy models, predation rates on adult models with decoy coloration were much higher than those on non-decoy adult models. Overall, our results suggest that predator-based selection is an important factor driving the ontogenetic loss of decoy coloration at similar sizes across these species and might be generalizable to other antipredator traits. [ABSTRACT FROM AUTHOR]

Studies of thermal sensitivity in ectotherms require accurate measurements of body temperature using a reliable device, including in field situations. In this study, we tested the accuracy of a compact and inexpensive mini-infrared thermometer (mini-IRT, 22.3 g) at close distance (within 5 mm) for measuring skin surface temperature of small lizards or their models (painted copper bars). First, we used copper bars to assess the effect of model width on the accuracy of the measurement. We placed the heated models on a cool background, and then surface temperatures were measured with a mini-IRT for comparison with a thermogram from an infrared camera (IRC). We also assessed the accuracy of the mini-IRT for measuring skin temperature for two species of small lizards in the laboratory and in the field, in comparison with the skin surface temperature measured with the IRC and with cloacal temperature measured with a thermocouple thermometer. Our results with inanimate models show that the accuracy of the mini-IRT at a distance within 5 mm is biologically acceptable (within ±1.0 °C of the mean value obtained using a more expensive, calibrated device) when the width is ≥ 7 mm. For live lizards, we observed highly significant relationships between skin surface temperature measured with the mini-IRT and temperatures measured with the two other devices. The mean discrepancies between the mini-IRT and other devices were acceptably small for geckos but larger for the smaller and more slender skinks. Taken together, our results suggest that skin temperature measured with the mini-IRT at a close distance is acceptable for field studies on lizards with an abdominal width ≥7 mm, serving as an inexpensive proxy for core body temperature in situations where portability and affordability of equipment and minimal animal handling are paramount. Nonetheless, calibration of mini-IRTs before use is strongly recommended. • A pocket-sized infrared thermometer (mini-IRT, 22.3 g) is an inexpensive field tool. • Mini-IRT values matched means for an infrared camera with models of width ≥5 mm. • Temperature discrepancies between devices were minor for live geckos, but larger for small skinks. • The mini-IRT is useful for measuring skin temperature of lizards when abdominal width ≥ 7 mm. • Calibration of mini-IRTs before use is strongly recommended. [ABSTRACT FROM AUTHOR]

Sexual size dimorphism (SSD) is widespread in animals, especially in lizards (Reptilia: Squamata), and is driven by fecundity selection, male–male competition, or other adaptive hypotheses. However, these selective pressures may vary through different life history periods; thus, it is essential to assess the relationship between growth and SSD. In this study, we tracked SSD dynamics between a "fading‐tail color skink" (blue tail skink whose tail is only blue during its juvenile stage: Plestiodon elegans) and a "nonfade color" tail skink (retains a blue tail throughout life: Plestiodon quadrilineatus) under a controlled experimental environment. We fitted growth curves of morphological traits (body mass, SVL, and TL) using three growth models (Logistic, Gompertz, and von Bertalanffy). We found that both skinks have male‐biased SSD as adults. Body mass has a higher goodness of fit (as represented by very high R2 values) using the von Bertalanffy model than the other two models. In contrast, SVL and TL for both skinks had higher goodness of fit when using the Gompertz model. Two lizards displayed divergent life history tactics: P. elegans grows faster, matures earlier (at 65 weeks), and presents an allometric growth rate, whereas P. quadrilineatus grows slower, matures later (at 106 weeks), and presents an isometric growth rate. Our findings imply that species‐ and sex‐specific trade‐offs in the allocation of energy to growth and reproduction may cause the growth patterns to diverge, ultimately resulting in the dissimilar patterns of SSD. [ABSTRACT FROM AUTHOR]

The critical thermal limits of organisms and the thermal sensitivity of their performance tend to vary predictably across latitudinal gradients. There has been comparatively less investigation into variation in thermal biology with elevation, despite similar gradients in environmental temperatures. To redress this, we examined critical thermal limits (CTmin and CTmax), thermal sensitivity of locomotor performance, and shelter site attributes, in three lizard species that replace one another along a contiguous elevation gradient in south-eastern Australia. The species examined consisted of a highland specialist, Liopholis guthega, mid-elevation species, Liopholis montana, and lowland species, Liopholis whitii. We found similar habitat attributes between the species, but L. guthega predominantly occurred in open habitat, which might reflect a strategy for maximizing exposure to insolation. We found intraspecific variation in lizard thermal traits, most notably in cold tolerance of L. guthega and in both heat and cold tolerance of L. whitii, suggesting population-specific variables acting on thermal physiology rather than a species distribution maintained by distinct thermal tolerances. This study represents one of the few examinations of thermal trait variability within and between species with elevation in a temperate system and provides evidence for thermal physiology driven by adaptation and/or physiological plasticity to local conditions. [ABSTRACT FROM AUTHOR]

Understanding genetic structure and diversity underpins the management of isolated populations. Small populations confined to islands may require effective genetic management for population persistence due to inbreeding and reduced genetic diversity. Endemic to the offshore islands of mainland Mauritius, the Bojer's skink (Gongylomorphus bojerii) has previously been managed as two genetic units due to divergence between populations to the north and south-east. In 2009, a few individuals were discovered on the south-eastern island Ile de la Passe (IDLP), an island within its former range where the species was believed to have gone extinct. This island was later supplemented with translocations from other south-eastern islands, but individual geographic origin and the genetic consequences of these translocations remains unknown. Demographic population history and translocation events were reconstructed using a suite of microsatellite markers and the mitochondrial DNA cytochrome b gene, assessing two northern and three south-eastern populations to infer the geographic origin of the IDLP individuals, and to assess the population's genetic diversity and structure. Although IDLP showed significant differentiation from all other populations, all analyses indicated a south-eastern origin, possibly founded by a single gravid female. Subsequent translocations have so far failed to ameliorate IDLP's genetic diversity. In addition, admixture analysis was used to track translocation and gene-flow in IDLP. We recommend using additional translocations from other south-eastern islands to further genetically support IDLP. Our study highlights the need to clarify cryptic population structure and utilise post-translocation genetic monitoring among similarly managed populations, particularly endangered island populations. [ABSTRACT FROM AUTHOR]

Seabirds are considered ecosystem engineers, because they facilitate ecosystem functioning (e.g., nutrient cycling), crucial for other marine and terrestrial species, including reptiles. However, studies of seabird-reptile interactions are limited. Here, we assessed the influence of the 'Critically Endangered' Whenua Hou Diving Petrel (Pelecanoides whenuahouensis) on the occurrence of two threatened skinks, Stewart Island green skink (Oligosoma aff. chloronoton) and southern grass skink (O. aff. polychroma). We surveyed skinks for 26 consecutive days at 51 sites with and 48 sites without Diving Petrel burrows in the dunes on Codfish Island (Whenua Hou), New Zealand. We used occupancy modelling to assess the influence of burrows on the occurrence of skinks, while accounting for other factors affecting occupancy (Ψ) and detection probabilities (p). Diving Petrel burrows had a contrasting effect on the occurrence of skinks. On average, Ψ̂ of Stewart Island green skinks was 114% higher at sites with burrows compared to sites without, while Ψ̂ of southern grass skinks was only 2% higher. Occurrence of both skinks was negatively influenced by the presence of the other skink species. On average p̂ were low: 0.013 and 0.038 for Stewart Island green and southern grass skinks, respectively. Stewart Island green skinks appear attracted to burrows, which might facilitate thermoregulation (i.e., shelter from temperature extremes). The larger Stewart Island green skinks may subsequently exclude the smaller southern grass skinks at burrows, causing the contrasting relationships. We suggest that these interspecific interactions should be considered when implementing conservation management, e.g., through the order of species reintroductions. [ABSTRACT FROM AUTHOR]