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Motivation: I present a database that contains information on multiple key traits for all 11,744 recognised species of squamates worldwide. The database encompasses key traits and a reasonably comprehensive picture of available public knowledge. I present comprehensive description of the sources and rationale leading to the assignment of each particular trait state for each species. I hope the dataset can serve the scientific community, promote research and understanding of the group, comparisons with other taxa, and assessment of conservation needs. Furthermore, gaps in our knowledge of squamate traits become readily apparent and will hopefully lead to further study and even better knowledge. Main types of variables contained: Morphological, ecological, life history, geographical and conservation‐related traits. Spatial location: Global. Time period: Late Holocene to recent. Major taxa and level of measurement: Squamata, species. Software format: xlsx. [ABSTRACT FROM AUTHOR]

In winter, many reptiles have a period of inactivity (“brumation”). During brumation there is no energetic intake, therefore there would be an advantage to reducing energetic expenditure. The size of energetically costly organs, a major determinant of metabolic rate, is known to be flexible in many tetrapods. Seasonal plasticity of organ size could serve as both an energy‐saving mechanism and a source of nutrients for brumating reptiles. We studied a population of an invasive gecko, Tarentola annularis, to test for seasonal changes in activity, metabolic rate, and mass of various organs. The observed period of inactivity was December–February. Standard metabolic rates during the activity season were 1.85 times higher than in brumating individuals. This may be attributed to decreased organ mass during winter: heart mass decreased by 37%, stomach mass by 25%, and liver mass by 69%. Interestingly, testes mass increased by 100% during winter, likely in preparation for the breeding season, suggesting that males prioritize breeding over other functions upon return to activity. The size of the kidneys and lungs remained constant. Organ atrophy occurred only after geckos reduced their activity, so we hypothesize that organ mass changes in response to (rather than in anticipation of) cold winter temperatures and the associated fasting. Degradation of visceral organs can maintain energy demands in times of low supply, and catabolism of the protein from these organs can serve as a source of both energy and water during brumation. These findings bring us closer to a mechanistic understanding of reptiles’ physiological adaptations to environmental changes. [ABSTRACT FROM AUTHOR]

Aim: Contemporary environmental, historical and evolutionary factors are increasingly used to decipher the drivers of spatial patterns of species richness. Evidence of such correlations for Chinese reptiles is scarce and poorly understood. We therefore explored the validity of the environmental capacity, historical climatic stability and diversification rates hypotheses on Chinese lizard richness. Location: Mainland China. Taxon: Squamata: Sauria. Methods: We mapped the distribution ranges of all 237 lizards in mainland China using a combination of different datasets. We used current environmental conditions (ambient energy, environmental productivity, and habitat heterogeneity), historical climate stability indices (long term: since ~3.3 Ma and short term: since the last glacial maximum) and mean tip diversification rates, to test whether current environmental conditions, historical climate change and diversification rates drive contemporary richness patterns of lizards in China. We applied piecewise structural equation models (pSEM) to jointly evaluate our hypotheses, considering direct and indirect effects. Results: Chinese lizards showed strong latitudinal diversity gradients. We found consistent support for contemporary climatic and environmental factors relationships with richness. Richness was also positively correlated with short‐term climatic stability, but less so with long‐term stability. Diversification rates were seldom found to be positively correlated with lizard richness. Main Conclusions: Our results support the environmental capacity and historical climate hypotheses, which link high richness to highly productive warm and stable regions (and low richness to cold and unstable regions). We conclude that post‐speciation dispersal and short‐term climatic oscillations quickly swamp the long‐term signal of diversification rates and climatic fluctuations, creating strong current climate–richness associations. [ABSTRACT FROM AUTHOR]

What factors render a species more vulnerable to extinction? In reptiles, foraging mode is a fundamental ecological dimension: some species actively search for immobile prey, whereas others ambush mobile prey. Foraging mode is linked to diet, morphology, movement ecology, and reproductive output, and hence plausibly might affect vulnerability to threatening processes. Our analyses of data on 1543 taxa revealed links between foraging mode and (IUCN) conservation status, but in opposite directions in the two main squamate groups. Ambush‐foraging snakes were more threatened and with declining populations than were active searchers, whereas lizards showed the reverse pattern. This divergence may be linked to differing consequences of foraging mode for feeding rates and reproductive frequency in snakes versus lizards. Our findings underscore the need for taxon‐specific conservation management, particularly in groups such as reptiles that have been neglected in global conservation prioritization. [ABSTRACT FROM AUTHOR]

Sexual selection has long been thought to increase species diversification. Sexually selected traits, such as sexual signals that contribute to reproductive isolation, were thought to promote diversification. However, studies exploring links between sexually selected traits and species diversification have thus far primarily focused on visual or acoustic signals. Many animals often employ chemical signals (i.e., pheromones) for sexual communications, but large-scale analyses on the role of chemical communications in driving species diversification have been missing. Here, for the first time, we investigate whether traits associated with chemical communications—the presence of follicular epidermal glands—promote diversification across 6,672 lizard species. In most analyses, we found no strong association between the presence of follicular epidermal glands and species diversification rates, either across all lizard species or at lower phylogenetic scales. Previous studies suggest that follicular gland secretions act as species recognition signals that prevent hybridization during speciation in lizards. However, we show that geographic range overlap was no different in sibling species pairs with and without follicular epidermal glands. Together, these results imply that either follicular epidermal glands do not primarily function in sexual communications or sexually selected traits in general (here chemical communication) have a limited effect on species diversification. In our additional analysis accounting for sex-specific differences in glands, we again found no detectable effect of follicular epidermal glands on species diversification rates. Thus, our study challenges the general role of sexually selected traits in broad-scale species diversification patterns. [ABSTRACT FROM AUTHOR]

Ecogeographic research into how species' forms vary across space, time, and climate has taken on new urgency due to contemporary global climate change. Research using museum specimens and other records to study biological rules like Bergmann's, Allen's, and Gloger's Rules has a long history and continues to generate publications and robust scientific debates. Despite the prevalence and history of the field, however, no simple guide on how to carry out such work has ever been published. To lower the barriers of entry for new researchers, this review was created as a practical guide on how to perform ecogeographic research. The guide consolidates disparately published methodologies into a single, convenient document that reviews the history and present of the field of ecogeographic rule research, and describes how to generate appropriate hypotheses, design experiments, gather, and analyze biotic and geographic data, and interpret the results in an ecologically meaningful manner. The result is a semi‐standardized guide that enables scientists at all levels from any institution to carry out an investigation from start to finish on any biological rule, taxon, and location of their choice. [ABSTRACT FROM AUTHOR]

Rensch's rule relates to a pattern whereby sexual size dimorphism is more female‐biased in small‐sized species and more male‐biased in large‐sized ones. We collected literature and museum data on the body size of males and females belonging to 4032 lizard species, as well as data on their reproductive modes and clutch sizes. We used phylogenetic comparative analyses, and general linear mixed models, to test Rensch's rule and examined how reproductive mode and clutch size affect sexual size dimorphism. Sexual size dimorphism was independent of clutch size in lizard species with variable clutch sizes and in oviparous lizards. Large litters were associated with female‐biased sexual dimorphism in viviparous and in scincomorph lizards. Inference regarding Rensch's rule depended on the analytical method used to identify it. The widely used, but less conservative, reduced major axis regression usually support Rensch's rule while ordinary least squares regressions mostly show isometric relationships. The rule tended to apply more to oviparous than to viviparous lizards. We infer that Rensch's rule is, at best, a weak pattern in lizards. This is especially true in viviparous lineages where females reproduce infrequently and therefore evolve large sizes to maximise fecundity, resulting in female‐biased dimorphism. [ABSTRACT FROM AUTHOR]

Aim: Many ectotherms are at risk from climate change as temperatures are increasingly exceeding their thermal limits. Many evaluations of the vulnerability of ectotherms to climate change have relied on statistical metrics derived from coarse‐scale climatic data, which may result in misleading predictions. By applying an integrative approach, we investigated geographical correlates of the vulnerability of lizards to climate change. Location: Globally. Taxon: Lizards. Methods: We combined data on lizard thermal physiology and ecology, with high‐resolution climate data and biophysical modelling to assess lizards' vulnerability to climate change. We calculated warming tolerance (difference between their body temperatures and upper thermal limits) and number of hours of activity. We investigated associations between warming tolerance and activity time with latitude, altitude and biome types. We compared our approach with traditional methods to calculate warming tolerance (using solely macroclimatic data). Results: We found no latitudinal trend in the warming tolerance of lizards calculated from body temperature, but there was a weak negative correlation with altitude. We found associations between hours of activity and latitude and altitude. Desert species showed narrower warming tolerance than tropical and temperate species. Desert species and temperate species had reduced hours of activity when compared to tropical species. When warming tolerance was calculated from macroclimatic data, however, it was positively correlated with latitude and altitude, and species from tropical forested biomes showed narrow warming tolerances. Main Conclusions: Vulnerability metrics calculated from macroclimatic data can produce divergent outcomes to those observed from fine‐scale climatic data. Our work indicates that the ability of desert and temperate lizard species to cope with heat stress by thermoregulating is more constrained than that of tropical species. Integrative assessments of ectotherms' vulnerability to climate change can highlight species and regions that should be prioritised for conservation management. [ABSTRACT FROM AUTHOR]

Aim: A decline in body size has been proposed as a universal response to global warming, but this is often questioned. We describe and characterize recent morphological changes in the avifauna of Israel as a whole and test several hypotheses regarding their cause. Location: Israel. Time period: 1950–2020. Major taxa studied: Aves. Methods: We analysed the morphology of 7,981 museum specimens. For each of the 106 species, we calculated the rate of change in mass, head and body length, wing length and approximate relative surface area, both over time and as a function of temperature anomaly (the difference between temperatures in a given year and the interannual average). We used phylogenetic generalized linear mixed models (PGLMMs) to determine trends and their relationship to the ecology of species. Results: Over the last 70 years there have been consistent changes through time in mass, length and surface area‐to‐volume ratio. Mass decreased by 18.3%, length increased by 5.1%, and surface area‐to‐volume ratio increased by 28.9%. The increase in the ratio of surface area to volume through time corresponds to a 12.2% increase per degree Celsius of warming. In contrast, changes in wing length were few and inconsistent. Most species changed in either mass or length, but seldom in both. The effect of rising temperature on morphology was roughly an order of magnitude stronger than the effect of a comparable geographical difference in habitat temperature. Changes were modulated by migratory habits but not explained by human commensalism or diet. Main conclusions: A decrease in mass and increase in length are widespread, both leading to higher relative surface area. Results conform with predicted responses to global warming, but not with any of our other tested hypotheses. If warming is the driver of these changes, the diverging responses observed between different species might represent different solutions to solve a common problem. [ABSTRACT FROM AUTHOR]

Aim: In the absence of topographic barriers to dispersal, spatial boundaries of species are largely governed by the environmental regimes they occupy. Flying lizards (Agamidae: Draco) from peninsular India have surmounted prominent geographic barriers, but their northern distribution abruptly ends at the 'Goa gap', a latitudinal boundary separating the wet and dry regions of the Western Ghats. Given their exclusively arboreal habits, we posit that canopy physiognomy determines Draco distribution in regions of climatic suitability. Location: Peninsular India. Taxa: Draco dussumieri, Monilesaurus rouxii. Methods: We analysed occurrence data collated from multiple sources against a suite of climatic and canopy‐specific predictors to model the occurrence of Draco. We used an information theoretic approach to binary logistic regression that incorporates presence/absence data, along with a maximum entropy‐based algorithm that models ecological niches in space using presence‐only data. Climatic data were obtained from CHELSA and WorldClim. We compared models for Draco dussumieri with the only other largely sympatric, arboreal agamid, Monilesaurus rouxii, which spans the Goa gap. Finally, we statistically tested how regions Draco inhabits differ in canopy physiognomy from the regions in the Western Ghats where it does not occur. Results: Canopy height was the most influential predictor of Draco presence in regions of climatic suitability under both the logistic regression and maximum entropy models. While climatically suitable regions occur north of the Goa gap, these regions harbour significantly lower canopies with lesser coverage. Despite a narrower range of climatic suitability, Monilesaurus has spanned the Goa gap, presumably because it is less dependent on canopy traits. Main conclusions: Lower canopies with lesser coverage act as a biogeographic barrier for the dispersal of Draco into regions of climatic suitability. In addition to being a climatic boundary, the Goa gap serves as a vegetational barrier that demarcates regions with significantly dissimilar canopy physiognomies. Our study highlights the importance of quantifying environmental regimes that organisms occupy to better understand distribution patterns. Our results implicitly predict the effects of deforestation on Draco distribution in the peninsula and therefore, influence its conservation strategy. [ABSTRACT FROM AUTHOR]

Aim: Birds have recently undergone a major extinction event which apparently is ongoing. According to some estimates, humans have caused the extinction of up to 20% of the entire avian species diversity since the latter part of the Pleistocene. Few attempts, however, were made to determine how many extinctions are actually known, rather than projected to have occurred. We aimed to quantify the known avian extinctions and assess the relevance of factors thought to have promoted their extinctions, that is, large size, flightlessness and insularity. Location: Global. Taxon: Aves. Materials and Methods: We collected data on bird extinctions from the literature. We recorded the geographic range, flight ability and body size of each species. If mass data were unavailable, we estimated them from linear measurements using machine learning tools. We modelled masses of extinct birds on those of extant ones and estimated the effects of taxonomy, body mass, insularity and flight ability. Results: We have identified 469 species of birds that humans, directly or indirectly, drove to extinction. These extinctions have predominantly occurred on islands. Extinct birds were often flightless. We estimated the body mass of 291 extinct species and found that overall, the median mass of extinct species was seven times larger than that of extant ones. Extinctions mostly occurred in families of large‐bodied birds, whilst lineages of small birds have fared better. Insular birds are overall larger than mainland birds, a trend that becomes even more evident when the extinct forms are analyzed. However, within lineages, sizes are only slightly larger on islands than on continents. Main conclusions: Our findings suggest that extinct bird species differed from extant birds by being larger, mostly restricted to islands, and often flightless. These factors made them especially vulnerable to human prosecution and to other anthropogenically related declines. Our modern understanding of birds is skewed with respect to the nature of avian faunas that existed before the current wave of human‐induced extinctions changed our world forever. [ABSTRACT FROM AUTHOR]

Biddick & Burns (2021) proposed a null/neutral model that reproduces the island rule as a product of random drift. We agree that it is unnecessary to assume adaptive processes driving island dwarfing or gigantism, but several flaws make their approach unrealistic and thus unsuitable as a stochastic model for evolutionary size changes. [ABSTRACT FROM AUTHOR]

The reptilian form of hibernation (brumation) is much less studied than its mammalian and insect equivalents. Hibernation and brumation share some basic features but may differ in others. Evidence for hypometabolism in brumating reptiles beyond the effect of temperature is sporadic and often ignored.We calculated the standard metabolic rates (SMR, oxygen uptake during inactivity), in winter and/or summer, of 156 individuals representing 59 species of Israeli squamates across all 17 local families. For 32 species, we measured the same individuals during both seasons. We measured gas exchange continuously in a dark metabolic chamber, under the average January high and low temperatures (20°C and 12°C), during daytime and nighttime. We examined how SMR changes with season, biome, body size, temperature and time of day, using phylogenetic mixed models.Metabolic rates increased at sunrise in the diurnal species, despite no light or other external cues, while in nocturnal species the metabolic rates did not increase. Cathemeral species shifted from a diurnal‐like diel pattern in winter to a nocturnal‐like pattern in summer. Regardless of season, Mediterranean species SMRs were 30% higher than similar‐sized desert species. Summer SMR of all species together scaled with body size with an exponent of 0.84 but dropped to 0.71 during brumation. Individuals measured during both seasons decreased their SMR between summer and winter by a 47%, on average, at 20°C and by 70% at 12°C. Q10 was 1.75 times higher in winter than in summer, possibly indicating an active suppression of metabolic processes under cold temperatures.Our results challenge the commonly held perception that squamate physiology is mainly shaped by temperature, with little role for intrinsic metabolic regulation. The patterns we describe indicate that seasonal, diel and geographic factors can trigger remarkable shifts in metabolism across squamate species. [ABSTRACT FROM AUTHOR]

The IUCN recently coordinated the first assessment of extinction risk of the world's reptile species. This monumental undertaking allows, for the first time, an examination of threats and prioritization of conservation effort, not just for reptiles, but for land vertebrates as a whole. Reptiles are now the largest class of land vertebrates in terms of species numbers. The dynamic nature of reptile taxonomy, the 18 years it took for the Global Reptile Assessment to be completed, the poor state of knowledge for many species – especially of squamates – and the evolving nature of threats, however, all highlight the need for continued monitoring of reptile species and threats. Here we review the status of reptile conservation assessments, and identify the challenges facing the next reptile assessments. We then recommend potential avenues that could facilitate efficient, accurate and timely future assessments. • The first Global Reptile assessment only covers ~85 % of species currently recognized • Newly described reptiles, Data Deficient species and species that underwent taxonomic splitting after they were assessed require new dedicated studies to correctly assess their conservation status • Small ranged species and species not observed for lengthy periods of time need to be carefully assessed in the future • The effects of climate change and future land use changes need to be well integrated into assessments • approaches to measuring Red List criteria need to be diversified, population trends, generation length and projected declines should increasingly be used [ABSTRACT FROM AUTHOR]

The world is facing a biodiversity crisis, and species are in danger of slipping towards extinction before having their conservation status formally determined. Australian squamates (snakes and lizards) form a highly diverse (over 1000 species) fauna, with 12% being either Data Deficient or Not Evaluated. We examined attributes of Australian squamates categorized as Data Deficient or Not Evaluated and compared key traits that are linked with threatened categories via univariate and multivariate models. We further used the machine learning model of Caetano et al. (2022, PloS Biology, 20, e3001544) to predict the putative extinction risk categories for Data Deficient and Not Evaluated Australian squamate species based on an analysis of reptiles globally. We found that Data Deficient Australian squamates are often lacking information on their drivers of threat and distribution, but not intrinsic traits or uncertain taxonomy. Data Deficient, Not Evaluated and threatened species often possess similar traits, including having small range sizes, being insular endemics and recently described, indicating that they may require some similar conservation management. Meanwhile, Not Evaluated species exhibit certain unique traits relative to evaluated species. We predicted 21% of Data Deficient and Not Evaluated species are threatened which is three times greater than currently assessed species (7%). This may indicate that a larger proportion of poorly known squamate species are more likely to be threatened than previously thought. Overall, our findings provide an important resource for the conservation management of Australian squamates by highlighting key traits and missing data, as well as providing a list of Data Deficient and Not Evaluated species that should be prioritized for research. [ABSTRACT FROM AUTHOR]

The article presents a global analysis of phylogenetic endemism patterns of land vertebrates, their environmental correlates, and threats. Topics discussed include main global determinants of phylogenetic endemism, importance of narrow-range species in sustaining biodiversity in the face of environmental change, and hypotheses and related predictors of phylogenetic endemism in tetrapods.

We created a database of lost and rediscovered tetrapod species, identified patterns in their distribution and factors influencing rediscovery. Tetrapod species are being lost at a faster rate than they are being rediscovered, due to slowing rates of rediscovery for amphibians, birds and mammals, and rapid rates of loss for reptiles. Finding lost species and preventing future losses should therefore be a conservation priority. By comparing the taxonomic and spatial distribution of lost and rediscovered tetrapod species, we have identified regions and taxa with many lost species in comparison to those that have been rediscovered—our results may help to prioritise search effort to find them. By identifying factors that influence rediscovery, we have improved our ability to broadly distinguish the types of species that are likely to be found from those that are not (because they are likely to be extinct). Some lost species, particularly those that are small and perceived to be uncharismatic, may have been neglected in terms of conservation effort, and other lost species may be hard to find due to their intrinsic characteristics and the characteristics of the environments they occupy (e.g. nocturnal species, fossorial species and species occupying habitats that are more difficult to survey such as wetlands). These lost species may genuinely await rediscovery. However, other lost species that possess characteristics associated with rediscovery (e.g. large species) and that are also associated with factors that negatively influence rediscovery (e.g. those occupying small islands) are more likely to be extinct. Our results may foster pragmatic search protocols that prioritise lost species likely to still exist. [ABSTRACT FROM AUTHOR]

In animals, the success of particular lineages can be measured in terms of their number of species, the extent of their geographic range, the breadth of their habitats and ecological niches, and the diversity of their morphological and life‐history traits. Here, we review the distribution, ecology, morphology and life history of skinks, a diverse lineage of terrestrial vertebrates. We compared key traits between the three subfamilies of skinks, and between skinks and non‐scincid lizards. There are currently 1743 described species of skink, which represent 24% of global lizard diversity. Since 2010, 16% of lizard descriptions have been of skinks. The centres of skink diversity are in Australia, New Guinea, southeast Asia, Oceania, Madagascar and central Africa. Compared with non‐scincid lizards, skinks have larger distributional ranges, but smaller body sizes. Sexual size dimorphism is rare in skinks. Almost a quarter (23%) of skinks exhibit limb reduction or loss, compared with just 3% of non‐scincid lizards. Skinks are more likely to be viviparous (34% of species) compared with non‐scincids (13%), and have higher clutch/litter sizes than non‐scincids. Although skinks mature later than non‐scincids, their longevity is similar to that exhibited by other lizard groups. Most skinks (88%) are active foragers, and they are more likely to be carnivorous than non‐scincids. Skinks are more likely to be diurnal or cathemeral than other lizard groups, but they generally have lower field body temperatures compared with non‐scincids. The success of skinks appears to be both a result of them hitting upon a winning body plan and ecology, and their capacity to regularly deviate from this body plan and adapt their ecology and life history (e.g. repeated limb reduction and loss, transitions to viviparity) to prevailing conditions. [ABSTRACT FROM AUTHOR]

Context: Skinks comprise the dominant component of the terrestrial vertebrate fauna in Oceania, New Guinea, and Eastern Wallacea (ONGEW). However, knowledge of their diversity is incomplete, and their conservation needs are poorly understood. Aims: To explore the diversity and threat status of the skinks of ONGEW and identify knowledge gaps and conservation needs. Methods: We compiled a list of all skink species occurring in the region and their threat categories designated by the International Union for Conservation of Nature. We used available genetic sequences deposited in the National Center for Biotechnology Information's GenBank to generate a phylogeny of the region's skinks. We then assessed their diversity within geographical sub-divisions and compared to other reptile taxa in the region. Key results: Approximately 300 species of skinks occur in ONGEW, making it the second largest global hotspot of skink diversity following Australia. Many phylogenetic relationships remain unresolved, and many species and genera are in need of taxonomic revision. One in five species are threatened with extinction, a higher proportion than almost all reptile families in the region. Conclusions: ONGEW contain a large proportion of global skink diversity on <1% of the Earth's landmass. Many are endemic and face risks such as habitat loss and invasive predators. Yet, little is known about them, and many species require taxonomic revision and threat level re-assessment. Implications. The skinks of ONGEW are a diverse yet underexplored group of terrestrial vertebrates, with many species likely facing extreme risks in the near future. Further research is needed to understand the threats they face and how to protect them. [ABSTRACT FROM AUTHOR]

The repeated evolution of gliding in diverse Asian vertebrate lineages is hypothesized to have been triggered by the dominance of tall dipterocarp trees in the tropical forests of Southeast Asia. These dipterocarp forests have acted as both centres of diversification and climatic refugia for gliding vertebrates, and support most of their extant diversity. We predict similarities in the diversification patterns of dipterocarp trees and gliding vertebrates, and specifically test whether episodic diversification events such as rate shifts and/or mass extinctions were temporally congruent in these groups. We analysed diversification patterns in reconstructed timetrees of Asian dipterocarps, the most speciose gliding vertebrates from different classes (Draco lizards, gliding frogs and Pteromyini squirrels) and compared them with similar-sized clades of non-gliding relatives (Diploderma lizards, Philautus frogs and Callosciurinae squirrels) from Southeast Asia. We found significant declines in net-diversification rates of dipterocarps and the gliding vertebrates during the Pliocene–Pleistocene, but not in the non-gliding groups. We conclude that the homogeneity and temporal coincidence of these rate declines point to a viable ecological correlation between dipterocarps and the gliding vertebrates. Further, we suggest that while the diversification decay in dipterocarps was precipitated by post-Miocene aridification of Asia, the crises in the gliding vertebrates were induced by both events concomitantly. [ABSTRACT FROM AUTHOR]

Aim: The identification of biogeographical zones has been fundamental in broadscale biodiversity analyses over the last 150 years. If processes underlying bioregionalization, such as climatic differences, tectonics and physical barriers, are consistent across vertebrate clades, we expect that groups with more similar ecological characteristics would show more similar bioregions. Lack of data has so far hampered the delineation of global bioregions for reptiles. Therefore, we integrated comprehensive geographic distribution and phylogenetic data of lepidosaurian reptiles to delineate global reptile bioregions, compare determinants of biogeographical boundaries across terrestrial vertebrates and test whether clades showing similar responses to environmental factors also show more similar bioregions. Location: Global. Time Period: Present. Major Taxa Studied: Reptiles, amphibians, birds, mammals. Methods: For reptiles, we used phylogenetic beta diversity to quantify changes in community composition, and hierarchical clustering to identify biogeographic 'realms' and 'regions'. Then, we assessed the determinants of biogeographical boundaries using spatially explicit regression models, testing the effect of climatic factors, physical barriers and tectonics. Bioregions of reptiles were compared to those of other vertebrate clades by testing the overall similarity of the spatial structure of bioregions, and the match of the position of biogeographical boundaries. Results: For reptiles, we identified 24 evolutionarily unique regions, nested within 14 realms. Biogeographical boundaries of reptiles were related to both climatic factors and past tectonic movements. Bioregions were very consistent across vertebrate clades. Bioregions of reptiles and mammals showed the highest similarity, followed by reptiles/birds and mammals/birds while amphibian bioregions were less similar to those of the other clades. Main Conclusions: The overall high similarity among bioregions suggests that bioregionalization was affected by similar underlying processes across terrestrial vertebrates. Nevertheless, clades with different eco‐physiological characteristics respond somewhat differently to the same environmental factors, resulting in similar but not identical regionalizations across vertebrate clades. [ABSTRACT FROM AUTHOR]

[Display omitted] • >4500 ultraconserved elements loci resolved the phylogeny of the snake superfamily Elapoidea. • Anatomical data and phylogeny supported establishment of a new Afro-Asian family of snakes, Micrelapidae. • Different phylogeny estimation methods inferred largely congruent topologies. • Time calibrated phylogeny supported the hypothesis of a rapid elapoid radiation in the Eocene. The highly diverse snake superfamily Elapoidea is considered to be a classic example of ancient, rapid radiation. Such radiations are challenging to fully resolve phylogenetically, with the highly diverse Elapoidea a case in point. Previous attempts at inferring a phylogeny of elapoids produced highly incongruent estimates of their evolutionary relationships, often with very low statistical support. We sought to resolve this situation by sequencing over 4,500 ultraconserved element loci from multiple representatives of every elapoid family/subfamily level taxon and inferring their phylogenetic relationships with multiple methods. Concatenation and multispecies coalescent based species trees yielded largely congruent and well-supported topologies. Hypotheses of a hard polytomy were not retained for any deep branches. Our phylogenies recovered Cyclocoridae and Elapidae as diverging early within Elapoidea. The Afro-Malagasy radiation of elapoid snakes, classified as multiple subfamilies of an inclusive Lamprophiidae by some earlier authors, was found to be monophyletic in all analyses. The genus Micrelaps was consistently recovered as sister to Lamprophiidae. We establish a new family, Micrelapidae fam. nov. , for Micrelaps and assign Brachyophis to this family based on cranial osteological synapomorphy. We estimate that Elapoidea originated in the early Eocene and rapidly diversified into all the major lineages during this epoch. Ecological opportunities presented by the post-Cretaceous-Paleogene mass extinction event may have promoted the explosive radiation of elapoid snakes. [ABSTRACT FROM AUTHOR]

Wild mammals are icons of conservation efforts, yet there is no rigorous estimate available for their overall global biomass. Biomass as a metric allows us to compare species with very different body sizes, and can serve as an indicator of wild mammal presence, trends, and impacts, on a global scale. Here, we compiled estimates of the total abundance (i.e., the number of individuals) of several hundred mammal species from the available data, and used these to build a model that infers the total biomass of terrestrial mammal species for which the global abundance is unknown. We present a detailed assessment, arriving at a total wet biomass of ≈20 million tonnes (Mt) for all terrestrial wild mammals (95% CI 13-38 Mt), i.e., ≈3 kg per person on earth. The primary contributors to the biomass of wild land mammals are large herbivores such as the white-tailed deer, wild boar, and African elephant. We find that even-hoofed mammals (artiodactyls, such as deer and boars) represent about half of the combined mass of terrestrial wild mammals. In addition, we estimated the total biomass of wild marine mammals at ≈40 Mt (95% CI 20-80 Mt), with baleen whales comprising more than half of this mass. In order to put wild mammal biomass into perspective, we additionally estimate the biomass of the remaining members of the class Mammalia. The total mammal biomass is overwhelmingly dominated by livestock (≈630 Mt) and humans (≈390 Mt). This work is a provisional census of wild mammal biomass on Earth and can serve as a benchmark for human impacts. [ABSTRACT FROM AUTHOR]

Aim: Limb reduction is a dramatic evolutionary transition, yet whether it is achieved in similar trajectories across clades, and its environmental drivers, remain unclear. We investigate the macroevolutionary and biogeographical patterns of limb reduction in skinks, where limb reduction occurred more often than in any other tetrapod clade, and test their associations with substrate categories using a global database. We test for habitat associations of body shapes in a group of Australian skinks using quantitative habitat data. Location: Global (Scincidae), Australia (Sphenomorphinae). Taxon: Skinks, Australian Sphenomorphinae. Materials and Methods: We use morphological data to explore the patterns of limb reduction in the world's skinks, investigating how body proportions differ across skink clades and subfamilies. We examine the relationships between body shape and substrate (coarsely classified). Further, we investigate the relationships between body shape and high‐resolution soil and climate properties extracted from each species' distribution for Australian sphenomorphines. Results: Relationships between limb lengths and trunk elongation show idiosyncratic patterns across skink clades. Presacral vertebrae numbers positively correlate with trunk elongation in all taxa, except Glaphyromorphus. Skinks from sandy habitats show greater disparity between forelimb and hindlimb lengths than all other substrate categories. In sphenomorphines, shorter limbs and elongated trunks correlate with colder, more humid microhabitats and richer soils; high limb disparity correlates with hot, arid microhabitats and sandy, poor substrates. Main Conclusions: The evolutionary trajectories of limb reduction in skinks are clade‐specific and sometimes unique. Selection for specific limb proportions and body sizes in limb‐reduced forms changes across substrates. On poor, sandy substrates of arid environments, body shapes with longer hindlimbs may be more efficient for locomotion in a granular fluid (i.e. sand) and exploit the air–substrate interface than complete limblessness. On richer, more humid substrates, such morphology is rare, indicating that navigating cluttered substrates selects for more equal and shorter limb lengths. [ABSTRACT FROM AUTHOR]

The Sahara Desert is the largest ecoregion in Africa, but its biodiversity in general, and reptile biodiversity in particular, are only superficially known and probably grossly underestimated. The dwarf-lizard genus Tropiocolotes is widely distributed in the region. The genus' taxonomy is plagued by serious nomenclatural problems that have led to a series of misidentifications of specimens in collections and in the literature. Analyzing variation in meristic and osteological characters of the Saharan species of Tropiocolotes, we found individuals from Algeria with unique external and internal morphological characters that distinguish them from all other species in the genus. We present a detailed account of these characters and describe two new species of Tropiocolotes from Algeria. Additionally, we provide the first detailed description of skulls of the genus, and designate a neotype to T. steudneri. [ABSTRACT FROM AUTHOR]

Aim: Limb‐reduced squamates are a convenient model system to investigate macroevolutionary trends in morphology. Here, we provide morphological, ecological and literature data on all known species of limb‐reduced skinks (Scincidae) and their relatives, representing one of the most diverse and widely distributed groups of limb‐reduced squamates. Location: Global. Taxon: Skinks (Reptilia, Squamata: Scincidae). Limb‐reduced forms. Methods: Morphological data were sourced from the primary literature, spanning a period of over 150 years. Linear body measurements were averaged across all values in the literature, preserving proportionality to body length. For digits and presacral vertebrae, we used maximum recorded counts. Ecological and biogeographical data were sourced from habitat assessments in the primary literature, online databases and field guides. Literature data were sorted according to type of study. To exemplify the applicability of the database, we used Markov‐chain ordered models to estimate the evolutionary frequency of limb reduction and loss in skinks. Results: We find evidence of limb reduction and loss in a total of 394 species worldwide, representing ~23% of all skink species, and ~30% of genera. The distribution of limb‐reduced and limbless forms differs from that of fully limbed forms, as they are present in all biogeographic realms with the almost complete exclusion of the Americas. We estimate that limb reduction evolved more than 50 times in skinks, and that loss of at least one limb pair evolved at least 24 times. Main conclusions The dataset captures a broad spectrum of morphological and ecological variation in a large, globally distributed taxonomic group. It establishes a widely applicable definition of limb reduction based on limb proportions as a reference for future studies. Such an extensive collection of morphological and ecological data can pave the way for investigations of dramatic morphological transitions and their ecological drivers at a global and local scale. [ABSTRACT FROM AUTHOR]

Many animals have strict diel activity patterns, with unique adaptations for either diurnal or nocturnal activity. Diel activity is phylogenetically conserved, yet evolutionary shifts in diel activity occur and lead to important changes in an organism's morphology, physiology, and behavior. We use phylogenetic comparative methods to examine the evolutionary history of diel activity in skinks, one of the largest families of terrestrial vertebrates. We examine how diel patterns are associated with microhabitat, ambient temperatures, and morphology. We found support for a nondiurnal ancestral skink. Strict diurnality in crown group skinks only evolved during the Paleogene. Nocturnal habits are associated with fossorial activity, limb reduction and loss, and warm temperatures. Our results shed light on the evolution of diel activity patterns in a large radiation of terrestrial ectotherms and reveal how both intrinsic biotic and extrinsic abiotic factors can shape the evolution of animal activity patterns. [ABSTRACT FROM AUTHOR]

The Red List of Threatened Species, published by the International Union for Conservation of Nature (IUCN), is a crucial tool for conservation decision-making. However, despite substantial effort, numerous species remain unassessed or have insufficient data available to be assigned a Red List extinction risk category. Moreover, the Red Listing process is subject to various sources of uncertainty and bias. The development of robust automated assessment methods could serve as an efficient and highly useful tool to accelerate the assessment process and offer provisional assessments. Here, we aimed to (1) present a machine learning–based automated extinction risk assessment method that can be used on less known species; (2) offer provisional assessments for all reptiles—the only major tetrapod group without a comprehensive Red List assessment; and (3) evaluate potential effects of human decision biases on the outcome of assessments. We use the method presented here to assess 4,369 reptile species that are currently unassessed or classified as Data Deficient by the IUCN. The models used in our predictions were 90% accurate in classifying species as threatened/nonthreatened, and 84% accurate in predicting specific extinction risk categories. Unassessed and Data Deficient reptiles were considerably more likely to be threatened than assessed species, adding to mounting evidence that these species warrant more conservation attention. The overall proportion of threatened species greatly increased when we included our provisional assessments. Assessor identities strongly affected prediction outcomes, suggesting that assessor effects need to be carefully considered in extinction risk assessments. Regions and taxa we identified as likely to be more threatened should be given increased attention in new assessments and conservation planning. Lastly, the method we present here can be easily implemented to help bridge the assessment gap for other less known taxa. The Red List of Threatened Species, published by the IUCN, is a crucial tool for conservation decision making, but is subject to various sources of uncertainty and bias. Modelling the threat status of all global reptiles identifies increased threat to many groups of reptiles across many regions of the world, beyond those currently recognized; moreover, it highlights the effects of the IUCN assessment procedure on eventual threat categories. [ABSTRACT FROM AUTHOR]

The skink genus Lobulia is endemic to New Guinea, the largest and highest tropical island in the world. Lobulia and its related genera represent an important component of the montane herpetofauna of New Guinea, but it remains understudied and poorly known. We here provide the first, large-scale, systematic revision of Lobulia , using molecular phylogenetic and morphological comparisons to assess the monophyly of the genus and the diversity of species within it. We find that Lobulia , as currently defined, is polyphyletic. The eight species currently assigned to it form three clades. Furthermore, many specimens from New Guinea of unknown specific affinity are genetically and morphologically distinct from each other. Based on these data, we re-diagnose Lobulia and two of its closely related genera, Prasinohaema and Papuascincus. We erect four new genera (Alpinoscincus gen. nov. Nubeoscincus gen. nov. Ornithuroscincus gen. nov. and Palaia gen. nov.) to address the problem of polyphyly and describe nine new species Lobulia fortis sp. nov. Lobulia huonensis sp. nov. Loublia marmorata sp. nov. Lobulia vogelkopensis sp. nov. Ornithuroscincus bengaun sp. nov. Ornithuroscincus inornatus sp. nov. Ornithuroscincus pterophilus sp. nov. Ornithuroscincus shearmani sp. nov. and Ornithuroscincus viridis sp. nov. We supplement this taxonomic revision by investigating the biogeographic history of Lobulia s.l. and find evidence for a large radiation in the accreted terranes of New Guinea, with multiple independent colonizations of montane habitats and subsequent recolonization of lowland habitats. Our study reinforces the uniqueness and richness of the montane herpetofauna of New Guinea and the importance of mountains to biodiversity in the Tropics. [ABSTRACT FROM AUTHOR]

We examined the taxonomy of the minute desert geckos of the Tropiocolotes nattereri species complex using the largest morphological sampling, and the first molecular assessment of intraspecific diversity within this complex. We examined variation in mitochondrial and nuclear markers (12S, ND2, c‐mos and MC1R) of 30 samples and analyzed the external morphology of 202 specimens, from across the entire distribution range of the complex from Egypt, Israel, Jordan and Saudi Arabia. We recognize two species under the name T. nattereri. We thus hereby describe a new species, T. yomtovi sp. n., and we redefine and redescribe T. nattereri, for which we designate a neotype. The species diversity in the genus Tropiocolotes increases to 15. [ABSTRACT FROM AUTHOR]

Microscale differences in the habitats organisms occupy can influence selection regimes and promote intraspecific variation of traits. Temperature‐dependent traits can be locally adapted to climatic conditions or be highly conserved and insensitive to directional selection under all but the most extreme regimes, and thus be similar across populations. The opposing slopes of Nahal Oren canyon in the Carmel Mountains, Israel, are strikingly different: the south‐facing slope receives intensive solar radiation, is hot and supports mostly annual vegetation, whereas the north‐facing slope is ~10°C cooler, more humid, and supports Mediterranean woodland. We examined whether these differences manifest in the thermal physiology of a common gecko species Ptyodactylus guttatus in controlled laboratory conditions. We predicted that geckos from the hotter south‐facing slope would prefer higher temperatures, have faster gut passage times, lower metabolic and evaporative water loss rates, and start diel activity earlier compared with north‐facing slope conspecifics. Contrary to these predictions, there were no differences between any of the ecophysiological traits in geckos from the opposing slopes. Nevertheless, our data showed that individuals from the north‐facing slope were generally more active in earlier hours of the afternoon compared with south‐facing individuals. We suggest that P. guttatus individuals disperse between the slopes and either gene‐flow or behavioral plasticity deter local adaptation, resulting in similar physiological traits. Perhaps a stronger contrast in climatic conditions and a stronger barrier are needed to result in interpopulation divergence in temperature‐dependent traits. Research Highlights: Similar ecophysiological traits of gecko populations across slopes of the same canyon, despite contrasting microclimatic conditions.Gene‐flow or behavioral plasticity mask local adaptation of ecophysiological traits to adjacent microclimates. [ABSTRACT FROM AUTHOR]

The Late Quaternary witnessed a dramatic wave of large mammal extinctions, that are usually attributed to either human hunting or climatic change. We hypothesized that the large mammals that survived the extinctions might have been endowed with larger brain sizes than their relatives, which could have conferred enhanced behavioral plasticity and the ability to cope with the rapidly changing Late Quaternary environmental conditions. We assembled data on brain sizes of 291 extant mammal species plus 50 more that went extinct during the Late Quaternary. Using logistic, and mixed effect models, and controlling for phylogeny and body mass, we found that large brains were associated with higher probability to survive the Late Quaternary extinctions, and that extant species have brains that are, on average, 53% larger when accounting for order as a random effect, and 83% when fitting a single regression line. Moreover, we found that models that used brain size in addition to body size predicted extinction status better than models that used only body size. We propose that possessing a large brain was an important, yet so far neglected characteristic of surviving megafauna species. [ABSTRACT FROM AUTHOR]

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]

Motivation: The understanding of physiological adaptations, of evolutionary radiations and of ecological responses to global change urges for global, comprehensive databases of the functional traits of extant organisms. The ability to maintain an adequate water balance is a critical functional property influencing the resilience of animal species to climate variation. In terrestrial or semi‐terrestrial organisms, total water loss includes a significant contribution from evaporative water loss (EWL). The analysis of geographic and phylogenetic variation in EWL rates must however account for differences in methods and potential confounding factors, which influence standard measures of whole‐organism water loss. We compiled the global and standardized SquamEWL database of total, respiratory and cutaneous EWL for 325 species and subspecies of squamate reptiles (793 samples and 2,536 estimates) from across the globe. An extensive set of companion data and annotations associated with the EWL measurements of potential value for future investigation, including metabolic rate data, is provided. We present preliminary descriptive statistics for the compiled data, discuss gaps and biases, and identify promising avenues to update, expand and explore this database. Main types of variables contained: Standard water loss rates, geographic data, metabolic rates. Spatial location: Global. Time period: Data were obtained from extant species and were collected between 1945 and 2020. Major taxa: Reptilia, Squamata including lizards, snakes and amphisbaenians. Level of measurements: Individual samples of animals from the same species, locality, age class and sex category. Software format: csv. [ABSTRACT FROM AUTHOR]

Aim: Identification of particular traits that predispose species to elevated extinction risk is an important component of proactive conservation. We capitalise on a recent strategic extinction risk assessment of all Australian squamate reptiles to identify intrinsic life history traits and extrinsic threats that correlate with extinction risk. We further assess whether extinction risk correlates differ between species impacted by different threatening processes (habitat loss vs. invasive species). Location: Australia. Taxon: Squamate reptiles. Methods: We used the IUCN Red List data for Australian squamates, and publicly available datasets for 14 intrinsic and extrinsic traits. We used phylogenetically controlled Bayesian inference to test hypotheses regarding relationships between extinction risk and species traits, environment, and threat measures. Results: We found that intrinsic characteristics (habitat specialisation, small range size and large body size), as well as extrinsic factors (high human footprint, accessibility from human population centres, cold temperatures and high rainfall), predispose a species to extinction. Similar predictors were important in threat‐specific analyses, although relationships were generally more uncertain. Conclusions: Our results largely accord with those of global and regional studies of extinction risk in reptiles and of terrestrial vertebrates more broadly. Our findings illustrate that there is no single pathway to extinction among Australian squamates. [ABSTRACT FROM AUTHOR]

Alopoglossus is a Neotropical lizard genus the taxonomy of which has extensively evolved over the past decade. Previous works suggest that many species still remain unnamed in this genus. Here, we expand the knowledge of Alopoglossus diversity in Amazonian lowlands. Molecular phylogenetic relationships, and species boundaries, were inferred based on the variation of mitochondrial (Cytb and ND4) and nuclear (SNCAIP and PRLR) loci. Morphological variation was assessed through analyses of external morphology of 401 specimens, covering the entire distribution range of Alopoglossus angulatus and its closely related taxa, and hemipenes of five specimens were examined. Combined, our evidence supports the recognition of three new species. We describe these species and redefine A. amazonius sensu stricto, increasing the number of known Alopoglossus species to 18. Our study also presents the first detailed descriptions of hemipenes for the genus. [ABSTRACT FROM AUTHOR]

Populations of the same species occupying different microhabitats can either exhibit generalized traits across them or display intraspecific variability, adapting to each microhabitat in order to maximize performance. Intraspecific variability contributes to the generation of diversity, following selection and adaptation, and understanding such variability is important for comprehending how individuals choose their microhabitats. Compared with interspecific variability, however, intraspecific variability in functional morphology and its relationship with microhabitat preference and use have been relatively little studied. Here we examined whether populations of the gecko Mediodactylus kotschyi that differ in the substrates they occupy display habitat-specific behaviors and differing morphologies associated with functional adaptation to their microhabitats. We collected 207 geckos from under or on rocks or on trees from seven populations in Greece. On large islands individuals occupy both substrates; whereas small islets are devoid of trees and the geckos are restricted to rocks, while on the mainland they are only found on trees. We determined gecko substrate preferences in the laboratory, together with their clinging abilities to the different substrates. We measured their limbs, digits, and claws and assessed how these measurements relate to clinging ability. Geckos from all populations preferred the tree made available to them, but this preference was not statistically significant. Geckos from both large and small islands clung better to the tree than to the rock in the laboratory, while those from the mainland clung similarly to both substrates. Geckos collected from trees had longer manual digits and hind limbs. Geckos collected from large and small islands had taller (longer on the dorso-ventral axis; henceforth "deeper") claws. Longer digits and deeper but shorter claws were associated with a better ability to cling to rocks. Our findings suggest that while M. kotschyi is potentially preferentially arboreal, due to the great variation and plasticity it possesses, it can successfully also exploit the habitats available on the smallest, treeless islets in the Aegean Sea. Our study suggests that the dichotomous use of generalist versus specialist in describing species' habitat use is oversimplified, and we suggest the use of a generalist–specialist gradient instead. [ABSTRACT FROM AUTHOR]

Multiple large-bodied species went extinct during the Pleistocene. Changing climates and/or human hunting are the main hypotheses used to explain these extinctions. We studied the causes of Pleistocene extinctions in the Southern Levant, and their subsequent effect on local hominin food spectra, by examining faunal remains in archaeological sites across the last 1.5 million years. We examined whether climate and climate changes, and/or human cultures, are associated with these declines. We recorded animal abundances published in the literature from 133 stratigraphic layers, across 58 Pleistocene and Early Holocene archaeological sites, in the Southern Levant. We used linear regressions and mixed models to assess the weighted mean mass of faunal assemblages through time and whether it was associated with temperature, paleorainfall, or paleoenvironment (C3 vs. C4 vegetation). We found that weighted mean body mass declined log-linearly through time. Mean hunted animal masses 10,500 years ago, were only 1.7% of those 1.5 million years ago. Neither body size at any period, nor size change from one layer to the next, were related to global temperature or to temperature changes. Throughout the Pleistocene, new human lineages hunted significantly smaller prey than the preceding ones. This suggests that humans extirpated megafauna throughout the Pleistocene, and when the largest species were depleted the next-largest were targeted. Technological advancements likely enabled subsequent human lineages to effectively hunt smaller prey replacing larger species that were hunted to extinction or until they became exceedingly rare. [ABSTRACT FROM AUTHOR]