The alpine biome, located at higher elevations of mountains worldwide, supports unique biodiversity and provides important ecosystem contributions to people. Despite the growing recognition of mountain biodiversity in international policy frameworks, substantial gaps remain in our understanding of how alpine biodiversity varies across mountain systems, undermining estimates of its conservation value and consequently effective conservation strategies. Here, we curate a dataset on alpine biodiversity, incorporating expert-validated data on species' elevational ranges for vascular plants, mammals, birds, and reptiles across 32 mountain ranges worldwide. We show that alpine biodiversity hotspots are concentrated in Neotropical regions, while most temperate regions represent coldspots with lower species richness. These patterns persist whether considering species with broad elevational ranges or only those strictly confined to the alpine zone. Unlike the classical latitudinal gradient of biodiversity, alpine richness patterns show no consistent relationship with latitude, highlighting the importance of regional history, landscape structure, and biogeographical processes.

Many reptiles inhabit deserts where extreme heat and aridity make it imperative to minimize evaporative water loss (EWL) in order to maintain a water balance. We compared the EWL of desert versus Mediterranean snakes and the content and composition of their epidermal lipids, which form the primary barrier against evaporation. We obtained shed skins from two farm‐grown species (a desert specialist viper Echis coloratus and its Mediterranean relative Daboia palaestinae ), and from 17 captive snake species of both Mediterranean and desert origins, kept under identical conditions. Total EWL was measured in live snakes using flow‐through respirometry. Cutaneous EWL was approximated in vitro through the shed skin, and epidermal lipids were quantified following extraction in n ‐hexane and identified using ultraperformance liquid chromatography–mass spectrometry (UPLC‐MS). Total EWL in vivo was 50% higher in Mediterranean than in desert species. In winter, in vitro EWL was 67% higher in Mediterranean than in desert species, and this difference rose to 178% in summer. EWL in vitro was negatively correlated with skin lipid content, and accordingly, desert species had twice the skin lipid content, but only in the summer. Seasonal differences were significant in the multi‐species comparison, and not between the farm‐grown Echis and Daboia . UPLC‐MS confirmed equal quantities of total lipids between the two viper species. However, the abundance of fatty acids was 84% higher in the desert specialist Echis , and these were, on average, ~1 double bond more saturated. There was no difference in ceramide abundance, but ceramide carbon chains were ~1 carbon atom longer in Echis . This lipid profile favours a more compact and stable lipid barrier structure, which improves the skin's resistance to evaporation. Our results show that snake epidermal lipid content and composition vary between biomes and seasons, enabling desert species to maintain water balance under the harsh heat and dryness conditions by limiting water loss. More broadly, this work highlights how fundamental biochemical traits can underlie major ecological differences, and how animals can benefit from these differences and adapt to thrive in extreme conditions. Read the free Plain Language Summary for this article on the Journal blog.

Human-induced environmental pressures are expected to intensify worldwide during the 21st century. Consequently, future-focused tools and approaches to anticipate pressures on biodiversity are key to effectively prioritize conservation actions and supplement existing approaches. Here, we develop a continuous conservation prioritization index, the Proactive Conservation Index (PCI), that integrates projected future extrinsic threats and traits that can predispose species' vulnerability. We used the PCI to assess the conservation priority of 33,560 species of land vertebrates worldwide, compared our results to the extinction risk categories of these species in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and examined spatial and phylogenetic patterns in these species future conservation needs. We found that median PCI scores broadly followed the order expected under the IUCN Red List classification, but varied substantially within each IUCN Red List category. According to the PCI, reptiles will be the group of land vertebrates with highest conservation priority in the future, despite amphibians currently having the highest proportion of threatened species according to the IUCN Red List. The PCI revealed that species in the Near Threatened category will have future conservation needs more similar to species in threatened categories than to species in the Least Concern category. Arid ecoregions, tropical montane forests, and islands showed the highest differences between conservation priorities set using the PCI and the IUCN Red List, indicating possible unrecognized future conservation needs. The proportion of threatened species according to the IUCN Red List was uncorrelated with the protected area coverage of each ecoregion, while the PCI, by design, highlighted currently unprotected ecoregions with sensitive fauna that will have high exposure to threats in the future. We produced a user-friendly web application to display our results and an R package to enable users to calculate PCI scores for any taxon and region, customizing the index according to the severity of predicted threats and importance of species attributes in other systems. Our novel index can help practitioners prioritize fine-scale species conservation actions in light of future threats and different global change scenarios.

Variation in life histories influences demographic processes, from adaptive changes to population declines leading to extinction. Among life history traits, generation length offers a critical feature to forecast species' demographic trajectories such as population declines (widely used by the IUCN Red List) and adaptability to environmental change over time. Therefore, estimates of generation length are crucial to monitor demographic stability or predict future changes in highly threatened organisms, particularly amphibians and reptiles, which are particularly threatened among vertebrates and for which uncertainty in future impacts remains high. Despite its importance, generation length for amphibians and reptiles is largely missing. Here, we aim to fill in this gap by modeling generation lengths for amphibians, squamates and testudines as a function of species size, climate, life history and phylogeny using generalized additive models and phylogenetic generalized least squares. We estimated generation lengths for 5059 (57%) amphibians, 8722 (73%) squamates and 117 (32%) testudines. Our models performed well for most families (e.g. Bufonidae among amphibians, Lacertidae and Colubridae among squamates, and Geoemydidae among testudines) while we found high uncertainty around the prediction of a few families, notably Chamaeleonidae. Species' body size and mean temperature were the main predictors of generation length in all groups. Although our estimates are not meant to substitute robust and validated measurements from field studies or natural history museums, they can help reduce existing biases in conservation assessments until field data is comprehensively available.

Context. Accurately describing a species' geographical distribution is important for informing research and conservation efforts. The citizen science platform iNaturalist provides a valuable resource for increasing our understanding of species distributions. Aims. To locate and document geographical range outliers in Australian skinks, and to provide evidence of populations undocumented in the existing literature. Methods. We compared observations of Australian skinks on iNaturalist to digital range maps from both the Global Assessment of Reptile Distributions (GARD), the International Union for the Conservation of Nature (IUCN), and a recent Australian reptile field guide. Outlying observations were examined to determine whether they were reliable records. We also made statistical comparisons of the characteristics of species with and without iNaturalist observations and outliers both among species range sizes and subfamilies. Key results. In total, 319 (of similar to 462) native Australian skink species had iNaturalist records. These species generally had larger range sizes, and skink subfamilies were represented unequally. Eighty-two skink species (25.7%) had at least one geographical range outlier, and 33 (10.3%) had at least one novel range outlier, unrecorded anywhere in the scientific literature. Range size did not affect the likelihood of a species to have outliers, but there was still a difference among subfamilies. We found 656 potentially interesting distribution anomalies. Most were not novel, but 111 were novel observations, including potential accidental translocations of a number of species. Most notably, evidence of an established population of Carlia sexdentata in Darwin, Northern Territory. Conclusions. Several factors affect how well Australian skink species are represented on iNaturalist, and many species are highly under-represented or unrepresented altogether. Despite this, our method was successful in providing evidence of a number of range anomalies, including some established populations that have not been formally documented. We also showed, through non-novel outliers, that the three map sources used in this study are not always the most accurate source for species distributions in Australian skinks. Implications. Our method can potentially be applied to many taxa around the world, so as to increase our understanding of species distributions.

Wildlife trade poses a major threat to biodiversity, yet the drivers determining which species are traded are not fully understood. Through a comprehensive collection of official and online trade data, we applied a binomial test to identify families that contain an unexpectedly large or small number of traded species. We also analyzed which factors predispose reptile species to be traded and explored whether traded species were more likely to be threatened with extinction. Of the 10,919 reptile species in our dataset, 3889 species (35.6%) were traded. There was strong evidence for taxonomic biases in trade risk. In particular, all turtle and crocodilian families had higher trade risk than other reptiles. Species with large body sizes, habitat generalists, insular endemics, and those found in regions with high gross domestic product were traded in greater quantities and more frequently. Species with small and large ranges were more frequently involved in trade, suggesting a demand for rare and common species in wildlife trade. When connecting trade risk to extinction risk, data-deficient and not-evaluated species had fewer traded species and were less likely to be traded than threatened or nonthreatened ones. Nonetheless, these species warrant special conservation attention considering their rarity, limited range size, and insufficient legal protection. Given the increased attention given to wildlife trade, we suggest implementing stronger regulatory measures to monitor and control the trade of reptile species, particularly those belonging to families with a high risk of being traded. Efforts should also prioritize the protection of species exhibiting traits that make them highly susceptible to exploitation. Finally, promoting international collaboration for stricter enforcement of wildlife trade regulations and support of sustainable trade practices can help mitigate the negative impacts on biodiversity.

Taxonomy is a highly dynamic science upon which most biodiversity studies rely. Constant revisions of species delimitation hypotheses, using ever-growing amounts of data and tools cause species numbers and identities to continuously and rapidly change. Reptiles are the most species rich terrestrial vertebrate group and are amongst the most threatened and least known vertebrate taxa, representing nearly half of all datadeficient terrestrial vertebrate species. Every year hundreds of new species are described and dozens are revised, resulting in synonymizations, splittings, generic reassignments, or elevation from synonymy or from subspecies into species status. The nomenclature of this group is therefore highly dynamic and consequently, to integrate available reptile datasets generally requires extensive nomenclature review, especially for broad scale analyses. letsRept is a new R package that integrates the Reptile Database - the best curated and reliable global taxonomic reference for reptiles - into the R programming environment. Its main functions allow users to retrieve the most up-to-date taxonomic information in real time, to compare lists of species names to current nomenclature, and to detect names that have been changed by either lumping or splitting, all through web scraping techniques. Additional functions allow to produce quick taxonomic summaries, access species accounts, retrieve full reference lists and more. By permitting to embed the Reptile Database directly into R workflows, the letsRept package improves the integration of datasets from different sources, with authoritative taxonomy, reducing data loss due to nomenclature mismatch and improving the consistency in biodiversity analyses.

The Galápagos marine iguana (Amblyrhynchus cristatus), the world's only marine lizard, feeds predominantly on algae. Owing to warming waters and reduced upwelling, algal abundance is reduced during El Niño events, causing high iguana mortality. During such periods, adult iguanas may shrink in size, a compelling phenomenon that has been suggested as an adaptation to reduce energetic needs. However, shifts in energy consumption have never been tested directly. We measured the body condition and metabolic rates of marine iguanas during an El Niño year and the subsequent neutral year. During El Niño, body mass relative to length was 17% lower, girth relative to length was 12% lower, and resting metabolic rates were 20% lower. This supports the hypothesis that marine iguanas partly offset the adverse effect of El Niño by an active response aimed at reducing their energy consumption, complementary to the energy-saving effect of body size reduction. Future ocean warming could force this endemic species to resort to such strategies increasingly often, and will likely exacerbate the already-high mortality rates caused by these events.

Sexual size dimorphism (SSD) is highly prevalent in nature. Several hypotheses aim to explain its evolution including sexual selection, differential equilibrium and ecological niche divergence. Disentangling the causal mechanism behind the evolution of SSD is challenging, as selection arising from multiple pressures on fitness may act simultaneously to generate observed patterns. Here, we use phylogenetic comparative methods to study the evolution of SSD across tetrapods globally. We estimate directional changes in body size evolution, and compare the number, phylogenetic position and magnitude of size changes between sexes. We find evidence that directional changes in size associated with SSD are typically more common in males-even in lineages where females are larger. However, underlying mechanisms differ among lineages-whereas SSD in amphibians becomes more male-biased with greater increases in male size and mammalian SSD becomes more female-biased with greater decreases in male size. Thus, differing mechanisms of directional body size evolution across sexes are essential to explain observed SSD patterns.

Explaining global species richness patterns is a major goal of evolution, ecology, and biogeography. These richness patterns are often attributed to spatial variation in diversification rates (speciation minus extinction). Surprisingly, prominent studies of birds, fish, and plants have reported higher speciation and/or diversification rates at higher latitudes, where species richness is lower. We hypothesize that these surprising findings are explained by the focus of those studies on relatively recent macroevolutionary rates, within the last ~20 million years. Here, we analyze global richness patterns among 10,213 squamates (lizards and snakes) and explore their underlying causes. We find that when diversification rates were quantified at more recent timescales, we observed mismatched patterns of rates and richness, similar to previous studies in other taxa. Importantly, diversification rates estimated over longer timescales were instead positively related to geographic richness patterns. These observations may help resolve the paradoxical results of previous studies in other taxa. We found that diversification rates were largely unrelated to climate, even though climate and richness were related. Instead, higher tropical richness was related to the ancient occupation of tropical regions, with colonization time the variable that explained the most variation in richness overall. We suggest that large-scale diversity patterns might be best understood by considering climate, deep-time diversification rates, and the time spent in different regions, rather than recent diversification rates alone.

Aim Species richness varies greatly over geographic gradients. Climate and other above-ground attributes are the most common variables used to explain animal richness patterns. However, soil properties may play an important role in shaping the richness of species living underground. Studies have yet to comprehensively analyse fossorial squamates' richness patterns and how soil properties influence them. We investigated how different predictors, including soil properties and climate, influenced the species richness of fully-fossorial, semi-fossorial, and non-fossorial squamates. Location Global. Taxon Reptilia: Squamata. Methods We categorised squamates into fully-fossorial, semi-fossorial, and non-fossorial, and assessed species richness for each category independently. We selected potential soil and climatic factors that could influence their richness. Then we used ordinary least squares regression models with spatially lagged variables (OLSL) and geographically weighted regression models with spatially lagged variables (GWRL) to investigate the influence of soil properties and climate on the species richness of each group. Results Fully-fossorial squamate richness peaks in Africa and South America. Semi-fossorial squamate richness is highest in South America and Australia. Non-fossorial squamates exhibit maximum species richness in South America and Southeast Asia. Species richness was more strongly associated with climate than soil properties in all groups. Nevertheless, as the levels of fossoriality increase, soil properties become more important correlates of species richness of squamates. Main Conclusions This study highlights the importance of incorporating soil factors alongside climate in the study of fossorial animal biogeography.

Maintaining the body's water balance is crucial for function and survival in all animals. Humidity conditions vary between different habitats and greatly affect an animal's evaporative water loss (EWL). Species inhabiting arid regions have adaptions to minimize water loss, which those adapted to life in humid regions may lack. Therefore, the physiology of species from different habitats could respond differentially to acute exposure to dry conditions. We measured the EWL and resting metabolic rates (RMRs) of 12 Israeli squamate species, from either mesic or xeric habitats, spanning four orders of magnitude in size. We treated the animals to dry and humid air simulating natural conditions (vapor pressure deficits 3 and 1 kPa, respectively) at an ecologically relevant temperature of 25°C. EWL rates were higher in dry air, and the effect was stronger in mesic species. EWL of mesic species in humid air is similar to EWL of xeric species in dry air, indicating similar EWL when tested under settings that match each species' natural conditions. In dry air, the RMR of small-bodied (<5 g) mesic species increased, whereas those of some small-bodied xeric species decreased. Small mesic species might be displaying stress from unnaturally dry conditions, whereas small xeric species possibly display an adaptation to minimize EWL by lowering RMR, thereby respiration rates. Physiological measurements are usually taken in dry air, and our results suggest previous experiments may contain a methodological bias. Future ecophysiological research needs to consider ambient humidity, by either varying experimental humidity to match natural conditions, or considering possible effects of humidity during analysis and interpretation of experiments and models.

Biodiversity and conservation are often the least noticed during armed conflicts. From October 1st, 2024, and again between June 13 and 24th, 2025, a brief but intense military conflict broke out between Israel and Iran. Iran primarily launched ballistic missile strikes, which Israel attempted to intercept using dedicated missiles. During both periods, we conducted a movement-monitoring experiment on Spalerosophis diadema snakes using accelerometer biologgers. In total, movements of four snakes were recorded during the conflict. We found that snakes exhibited immediate movement responses to missile attacks that produced loud explosion noises. Moreover, the strength of these movements increased with the intensity of the attacks; however, snakes showed little to no response to such noises after feeding. Here, we report for the first time the movement responses of snakes to missile attacks producing loud explosions. While the consequences of human armed conflict for wildlife may vary depending on the context, our findings emphasize that the role of wildlife as potential victims is often overlooked.

Marine iguanas occasionally face severe food shortages because of algal dieback during El Ni & ntilde;o events. Research on their adaptations to these periods has highlighted their unique ability to shrink in body length, which reduces their energetic needs. Additional mechanisms, like sustaining lower body temperatures and metabolic rates, could potentially also lower energy consumption, but have never been examined. We measured 665 iguanas over an 11-year period including three El Ni & ntilde;o events, and examined how heart rates (a proxy for metabolic rates) and body temperatures change with sea-surface temperature oscillations (Oceanic Ni & ntilde;o Index, ONI). Heart rate (adjusting for body size, temperature, season, and study site) was negatively correlated with ONI and lower during El Ni & ntilde;o, whereas the adjusted body temperature did not correlate with ONI or differ between El Ni & ntilde;o and other periods. We therefore hypothesize that marine iguanas can depress their metabolic rates in response to the harsh conditions, an adaptation that is complementary to shrinking and may further enhance their survival through periods of limited food. Direct metabolic measurements are needed to test this hypothesis.

Marked with high levels of endemism and in situ radiations, the Western Ghats mountains make for a compelling backdrop to examine processes that lead to the formation and maintenance of species. Regional geographic barriers and paleoclimatic fluctuations have been implicated as drivers of speciation, but their roles have not been explicitly tested in a phylogenomic framework. We integrated mitochondrial DNA, genome-wide SNPs and climatic data to examine the influence of geographic barriers and climatic transitions in shaping phylogeography and potential speciation in the Peninsular Indian Flying lizard (Draco dussumieri). We found strong evidence for two independently evolving, geographically distinct, northern and southern lineages within D. dussumieri that diverged during the early Pleistocene, and a gradient of admixed populations across a broad hybrid zone in the Central Western Ghats. Migrations after initial divergence were continuous, but gene flow remained consistently below thresholds required to homogenise lineages. We found more support for isolation by environment (especially rainfall regimes) than by distance. The range-break between lineages occurs at a transition zone in the Central Western Ghats that separates dissimilar rainfall regimes with no physical barriers. This limit is potentially an ecological barrier, which nevertheless was permeable during glacial maxima. We hypothesise that similar phylogeographic patterns will emerge in other widespread, wet-adapted species in the Western Ghats that presumably endured the same climatic processes.

Israel has a long and rich history of herpetological research, with many studies of local reptiles and amphibians. Despite being one of the most thoroughly surveyed countries in the region, surprising discoveries about its herpetofauna continue to emerge. The gecko Hemidactylus turcicus is currently regarded as the only species of its genus in Israel. Based on genetic data and phylogenetic analyses, we confirm the occurrence of another Hemidactylus species in Israel. Specimens from the southern Arava Valley, until now thought to represent H. turcicus were found to belong to H. granosus , a species that until now was only known from Egypt, southern Jordan and Saudi Arabia. This research thus increases the number of Hemidactylus species in Israel to two and reveals a geographic connection between H. granosus populations in Egypt and the Sinai Peninsula, eastward through southern Israel into southern Jordan and southwards towards western and central Saudi Arabia.

Aim Sexual size dimorphism (SSD) is widespread in the animal kingdom. The direction and magnitude of SSD differ considerably across taxa, potentially due to different selective forces acting on female and male sizes. We assembled a comprehensive database of mean body sizes for female and male squamate species. We then tested for associations between the degree and direction of sexual size dimorphism and environmental factors, clutch/litter sizes, reproductive modes, substrate types, and species richness (a common measure of interspecific competition). Location Global. Time Period Present. Major Taxa Studied Squamata (Reptilia). Methods We studied SSD patterns and their correlates for 11792 squamate species. We also tested the effect of the number of putative competitors on SSD within (similar to 9915 km(2)) grid cells. We applied phylogenetic path analysis and phylogenetic generalised least squares regression (PGLS) at the species level and applied spatial auto-regressive (SAR) multiple regressions at assemblage levels. Results In general, snake females are larger than males, whereas male lizards are larger, on average, than females. Female squamates in general are larger than males in cold regions, while in warm regions, particularly in deserts, males are usually larger than females. SSD became more female-biased (i.e., larger females) as clutch size increased, and viviparous taxa had more female-biased SSD. There was little relationship between the magnitude of SSD and species richness. Sexual size dimorphism did not vary significantly across substrate types. Main Conclusion We suggest that the mechanisms driving squamate SSD differ between oviparous and viviparous taxa. The more female-biased SSD in colder regions is likely driven by fecundity selection, while a male bias in warmer regions may be associated with sexual selection. However, we found little evidence to suggest that natural selection for substrates, or resource-based competition, affects squamate sexual size dimorphism and suspect the underlying hypotheses may be flawed, and/or that species richness is a poor measure of the intensity of interspecific competition.