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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]

Issue: Sexual size dimorphism is thought to vary in a predictable manner with overall body size, a pattern named "Rensch's rule". The rule is thought to suggest different predictions for taxa with female‐ and male‐biased dimorphism. This leaves taxa where both types of dimorphism are common in limbo. Rensch's rule is usually estimated using the reduced major axis (RMA) slope of a regression of male size on female size. A slope steeper than one shows support for the rule. Evidence: We show that the predictions of Rensch's rule for male‐ and female‐biased taxa are, in fact, the same and offer a unified definition of the rule. Using numerical examples and data from the literature, we show that RMA and ordinary least squares (OLS) methods of line fitting can produce conflicting results, suggesting that RMA is a less conservative way to test the rule. Conclusion: We recommend that both line‐fitting methods are used to estimate Rensch's rule, with strong support being claimed only when the results of both agree with each other. Alternatively, we suggest that tests are conducted in a way that agrees with the definition of the rule (i.e., that size dimorphism is regressed on the mean size of males and females of the species). [ABSTRACT FROM AUTHOR]

Amniote vertebrates share a suite of extra-embryonic membranes that distinguish them from anamniotes. Other than that, however, their reproductive characteristics could not be more different. They differ in basic ectothermic vs endothermic physiology, in that two clades evolved powered flight, and one clade evolved a protective shell. In terms of reproductive strategies, some produce eggs and others give birth to live young, at various degrees of development. Crucially, endotherms provide lengthy parental care, including thermal and food provisioning—whereas ectotherms seldom do. These differences could be expected to manifest themselves in major differences between clades in quantitative reproductive traits. We review the reproductive characteristics, and the distributions of brood sizes, breeding frequencies, offspring sizes and their derivatives (yearly fecundity and biomass production rates) of the four major amniote clades (mammals, birds, turtles and squamates), and several major subclades (birds: Palaeognathae, Galloanserae, Neoaves; mammals: Metatheria and Eutheria). While there are differences between these clades in some of these traits, they generally show similar ranges, distribution shapes and central tendencies across birds, placental mammals and squamates. Marsupials and turtles, however, differ in having smaller offspring, a strategy which subsequently influences other traits. [ABSTRACT FROM AUTHOR]

Two species of Alopoglossus (A. angulatus and A. meloi) were recognized to occur in the Guiana Shield lowlands, northeastern Amazonia. A third group of populations forming a distinct genetic lineage related to Alopoglossus avilapiresae was recently documented in the region. The Guiana Shield lowlands area also encompasses the type locality of Alopoglossus copii surinamensis (currently considered a synonym of A. angulatus). Aiming at describing a possible new species of Alopoglossus from the Guiana Shield and evaluating the taxonomic status of A. copii surinamensis, we analyzed variation in scutellation and morphometrics of the two nominal species of Alopoglossus occurring in the Guiana Shield and A. avilapiresae, which was recovered as the sister clade of the new Guiana Shield lineage, by examining 361 specimens from French Guiana, Brazil, Suriname, Guyana, Colombia, Ecuador, and Peru. Our results revealed a distinct combination of diagnostic characters that supports the description of specimens displaying the third Guiana Shield lineage as a new species. The new species is also distinct from A. copii surinamensis that we retain under a synonym of A. angulatus after examination of all species of the angulatus group and by considering updated diagnostic characters. The new taxon described here increases the total number of known species of Alopoglossus to 15. [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]

Geckos are a hyper-diverse, ancient, and globally distributed group. They have diverged early from other squamates and thus can be expected to differ from them along multiple ecological, life history, and biogeographic axes. I review a wide range of gecko traits, comparing them to those of other lizard taxa, to identify the unique, and unifying, attributes of geckos among lizards, based on comprehensive databases of lizard distributions and biological attributes. Few traits completely separate geckos from other lizard taxa, yet they differ to a large degree along many axes: they are more restricted to low latitudes and altitudes, are especially diverse on islands, but relatively scarce in America. They are small lizards, that lay small, fixed clutch sizes, for which they compensate only partially by laying frequently. Because they mature at relatively similar ages and have similar lifespans to other lizards, geckos produce fewer offspring over a year, and over their lifetimes, perhaps implying that they enjoy higher survival rates. While being the only large lizard clade of predominantly nocturnal lizards a large proportion of species is active by day. Gecko body temperatures and preferred temperatures are lower than those of other lizards –even when they are compared to lizards with similar activity times. Worryingly, most geckos have small ranges that often reside completely outside of protected areas – much more frequently than in other reptile and vertebrate taxa. [ABSTRACT FROM AUTHOR]

Aim: Clutch size is a key life‐history trait. In lizards, it ranges over two orders of magnitude. The global drivers of spatial and phylogenetic variation in clutch have been extensively studied in birds, but such tests in other organisms are lacking. To test the generality of latitudinal gradients in clutch size, and their putative drivers, we present the first global‐scale analysis of clutch sizes across lizard taxa. Location: Global. Time period: Recent. Major taxa studied: Lizards (Reptilia, Squamata, Sauria). Methods: We analysed clutch‐size data for over 3,900 lizard species, using phylogenetic generalized least‐square regression to study the relationships between clutch sizes and environmental (temperature, precipitation, seasonality, primary productivity, insularity) and ecological factors (body mass, insularity, activity times, and microhabitat use). Results: Larger clutches are laid at higher latitudes and in more productive and seasonal environments. Insular taxa lay smaller clutches on average. Temperature and precipitation per se are unrelated to clutch sizes. In Africa, patterns differ from those on other continents. Lineages laying small fixed clutches are restricted to low latitudes. Main conclusions: We suggest that the constraint imposed by a short activity season, coupled with abundant resources, is the main driver of large‐clutch evolution at high latitudes and in highly seasonal regions. We hypothesize that such conditions – which are unsuitable for species constrained to laying multiple small clutches – may limit the distribution of fixed‐clutch taxa. [ABSTRACT FROM AUTHOR]

Viviparity (live‐bearing) has independently evolved from oviparity (egg‐laying) in more than 100 lineages of squamates (lizards and snakes).We might expect consequent shifts in selective forces to affect per‐brood reproductive investment (RI = total mass of offspring relative to maternal mass) and in the way in which that output is partitioned (number vs. size of offspring per brood). Based on the assumption that newly born offspring are heavier than eggs, we predicted that live‐bearing must entail either increased RI or a reduction in offspring size and/or fecundity.However, our phylogenetically controlled analysis of data on 1,259 squamate species revealed no significant differences in mean offspring size, clutch size or RI between oviparous and viviparous squamates.We attribute this paradoxical result to (1) strong selection on offspring sizes, unaffected by parity mode, (2) the lack of a larval stage in amniotes, favouring large eggs even in the ancestral oviparous mode and (3) the ability of viviparous females to decrease the mass of uterine embryos by reducing extra‐embryonic water stores.Our analysis shows that squamate eggs (when laid) weigh about the same as the hatchlings that emerge from them (despite a many‐fold increase in embryo mass during incubation). Most of the egg mass is due to components (such as water stores and the eggshell) not required for oviductal incubation. That repackaging enables live‐born offspring to be accommodated within the mother's body without increasing total litter mass.The consequent stasis in reproductive burden during the evolutionary transition from oviparity to viviparity may have facilitated frequent shifts in parity modes. [ABSTRACT FROM AUTHOR]

New Guinea has been considered both as a refuge for mesic rainforest-associated lineages that contracted in response to the late Cenozoic aridification of Australia and as a centre of biotic diversification and radiation since the mid-Miocene or earlier. Here, we estimate the diversity and a phylogeny for the Australo-Papuan forest dragons (Sauria: Agamidae; ~20 species) in order to examine the following: (1) whether New Guinea and/or proto-Papuan Islands may have been a biogeographical refuge or a source for diversity in Australia; (2) whether mesic rainforest environments are ancestral to the entire radiation, as may be predicted by the New Guinea refuge hypothesis; and (3) more broadly, how agamid ecological diversity varies across the contrasting environments of Australia and New Guinea. Patterns of lineage distribution and diversity suggest that extinction in Australia, and colonization and radiation on proto-Papuan islands, have both shaped the extant diversity and distribution of forest dragons since the mid-Miocene. The ancestral biome for all Australo-Papuan agamids is ambiguous. Both rainforest and arid-adapted radiations probably started in the early Miocene. However, despite deep-lineage diversity in New Guinea rainforest habitats, overall species and ecological diversity is low when compared with more arid areas, with terrestrial taxa being strikingly absent. [ABSTRACT FROM AUTHOR]

Mammals and birds provide food for their young after birth, but such provisioning is almost absent in other vertebrates. A recent theory suggested that, in addition to thermoregulation, the large discrepancy in size between adult and young ectothermic vertebrates precludes them from providing for their young, whereas the relatively large offspring of endotherms are easier to provision. I show here that reptile neonates and hatchlings are as large as those of mammals and birds. Differences in size between adults and young thus cannot explain the lack of parental provisioning in reptiles. I suggest that the large size at birth is the ancestral condition in amniotes as a whole and that provisioning has thus evolved after endothermy. [ABSTRACT FROM AUTHOR]

Body size shapes ecological interactions across and within species, ultimately influencing the evolution of large‐scale biodiversity patterns. Therefore, macroecological studies of body size provide a link between spatial variation in selection regimes and the evolution of animal assemblages through space. Multiple hypotheses have been formulated to explain the evolution of spatial gradients of animal body size, predominantly driven by thermal (Bergmann's rule), humidity ('water conservation hypothesis') and resource constraints ('resource rule', 'seasonality rule') on physiological homeostasis. However, while integrative tests of all four hypotheses combined are needed, the focus of such empirical efforts needs to move beyond the traditional endotherm–ectotherm dichotomy, to instead interrogate the role that variation in lifestyles within major lineages (e.g. classes) play in creating neglected scenarios of selection via analyses of largely overlooked environment–body size interactions. Here, we test all four rules above using a global database spanning 99% of modern species of an entire Order of legless, predominantly underground‐dwelling amphibians (Gymnophiona, or caecilians). We found a consistent effect of increasing precipitation (and resource abundance) on body size reductions (supporting the water conservation hypothesis), while Bergmann's, the seasonality and resource rules are rejected. We argue that subterranean lifestyles minimize the effects of aboveground selection agents, making humidity a dominant selection pressure – aridity promotes larger body sizes that reduce risk of evaporative dehydration, while smaller sizes occur in wetter environments where dehydration constraints are relaxed. We discuss the links between these principles with the physiological constraints that may have influenced the tropically‐restricted global radiation of caecilians. [ABSTRACT FROM AUTHOR]

Models for biodiversity growth on the remote oceanic islands assume that in situ cladogenesis is a major contributor. To test this, we compiled occurrence data for 194 terrestrial reptile species on 53 volcanically‐constructed middle‐ to low‐latitude landmasses worldwide. Despite 273 native island‐species records, there are only 8–12 cases of the phenomenon, including just two radiations. Diversification frequencies are largely uncorrelated with island area, age, maximum altitude, and isolation. Furthermore, there is no indication that the presence of non‐sister congeners on an island stymies the process. Diversity on individual oceanic islands therefore results primarily from immigration and anageneis, but this is not a simple matter. Clusters that are difficult to reach (far or challenging to get to) or thrive upon (e.g. Canaries, Galápagos) have relatively few clades (3–8), some of which have many species (6–14), and all host at least one endemic genus. In these settings, diversity grows mainly by intra‐archipelago transfer followed by within‐island anagenetic speciation. In contrast, those island groups that are easier to disperse to (characterized by short distances and conducive transit conditions) and harbour more benign habitats (e.g. Comoros, Lesser Antilles) have been settled by many ancestor‐colonizers (≥ 14), but each clade has few derived species (≤ 4). These archipelagoes lack especially distinctive lineages. Models explaining the assembly and growth of terrestrial biotic suites on the volcanic ocean islands thus need to accommodate these new insights. [ABSTRACT FROM AUTHOR]

The magnitude and direction of sexual size dimorphism (SSD) varies greatly across the animal kingdom, reflecting differential selection pressures on the reproductive and/or ecological roles of males and females. If the selection pressures and constraints imposed on body size change along environmental gradients, then SSD will vary geographically in a predictable way. Here, we uncover a biogeographical reversal in SSD of lizards from Central and North America: in warm, low latitude environments, males are larger than females, but at colder, high latitudes, females are larger than males. Comparisons to expectations under a Brownian motion model of SSD evolution indicate that this pattern reflects differences in the evolutionary rates and/or trajectories of sex‐specific body sizes. The SSD gradient we found is strongly related to mean annual temperature, but is independent of species richness and body size differences among species within grid cells, suggesting that the biogeography of SSD reflects gradients in sexual and/or fecundity selection, rather than intersexual niche divergence to minimize intraspecific competition. We demonstrate that the SSD gradient is driven by stronger variation in male size than in female size and is independent of clutch mass. This suggests that gradients in sexual selection and male–male competition, rather than fecundity selection to maximize reproductive output by females in seasonal environments, are predominantly responsible for the gradient. [ABSTRACT FROM AUTHOR]

The morphology of organisms reflects a balance between their evolutionary history, functional demands, and biomechanical constraints imposed by the immediate environment. In many fish species, a marked shift in the selection regime is evident when pelagic larvae, which swim and feed in the open ocean, settle in their adult benthic habitat. This shift is particularly dramatic in coral‐reef fishes, where the adult habitat is immensely complex. However, whether the adult trophic ecotype affects the morphology of early‐life stages is unclear. We measured a suite of 26 functional‐morphological traits in the head and body of larvae from an ontogenetic series of 16 labrid species. Using phylogenetic comparative methods, we reconstructed the location of adaptive peaks of larvae whose adults are associated with different trophic ecotypes. We found that the morphospace occupation in these larvae is largely driven by divergent adaptations to the adult benthic habitats. The disparity between adaptive peaks is achieved early and does not monotonically increase with size. Our findings thus refute the notion that larvae rapidly acquire the trophic‐specific traits during a metamorphic period immediately prior to settlement. This early specialization might be due to the highly complex musculoskeletal system of the head that cannot be rapidly modified. [ABSTRACT FROM AUTHOR]

Faunal lists are important tools in ecology, biogeography, and conservation planning. Such lists can identify gaps in our knowledge of the distribution and taxonomy of regional faunas, and highlight issues needing further study. We present an up to date list of all land vertebrates occurring in Israel. We identify 786 species, of which 551 are birds, 130 are mammals, 97 are reptiles and eight are amphibians. Of these 369 species breed in Israel (including reintroductions), 199 (mostly birds) are regular visitors and 182 are accidental. Fourteen other species are invasive, and 22 species are extinct. We identify issues with the taxonomy and status of several species, and note recent developments in our understanding the Israeli land vertebrate fauna. [ABSTRACT FROM AUTHOR]

Aim: Longevity is a critical life‐history trait of organisms. Multiple abiotic and biotic factors are thought to exert different selection pressures, resulting in a great variation in species longevity. We examined factors that, according to evolutionary theories of senescence, are thought to be related to extrinsic and intrinsic mortality rates, and thus shape the variation in longevity among amphibians. Location: World‐wide. Time period: Present. Major taxa studied: Amphibia. Methods: We collected literature data on the maximum longevities of 527 amphibian species. Correcting for phylogeny and sample size, we modelled the relationship between amphibian longevity and body size. We also examined the effects of chemical protection, activity period, microhabitat preferences and annual temperature on amphibian longevity. Results: In general, members of larger amphibian species live longer. Body size, however, explained less of the variation in amphibian longevity than it does in mammals and birds. Nocturnal amphibians, species that use poison for defence and those inhabiting cold regions live longer, but microhabitat preferences had little effect. Main conclusions: Our results supported predictions of evolutionary theories of senescence. Large amphibians living in colder environments probably experience slower growth and metabolic rates, reducing intrinsic drivers of mortality and increasing longevity. Moreover, species that reduce extrinsic mortality pressures via chemical protection and nocturnality have increased longevity. Sampling captive animals and sampling more individuals of a species increases the chances of finding older individuals and should be corrected for when studying maximum longevity. [ABSTRACT FROM AUTHOR]

Motivation: over the last 12 years I have been collecting trait and geographic data on lizards. These data could be useful for scientists studying this remarkable reptilian radiation. Furthermore, as published data for some of the less well known species are scarce, I hope this study can initiate a community effort to fill in data gaps. I present geographical, morphological, ecological, physiological and life history data for the 6,657 known species of lizards. I further indicate whether there are phylogenetic data associated with them, and their threat assessment, if they have one. I present descriptive statistics regarding these traits and point to avenues for future research using the dataset. Main types of variable contained: body size, ecological, thermal biology, geographic, phylogenetic and life history data. Spatial location: Global. Time period: data are for species known from living, or recently extinct species. Most underlying data were collected during the 20th and 21st centuries. Major taxa: Reptilia, Sauria (Squamata, including Amphisbaenia but excluding Serpentes). Level of measurement: species. Software format: csv. [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]

Aim Small geographic ranges make species especially prone to extinction from anthropogenic disturbances or natural stochastic events. We assemble and analyse a comprehensive dataset of all the world's lizard species and identify the species with the smallest ranges-those known only from their type localities. We compare them to wide-ranging species to infer whether specific geographic regions or biological traits predispose species to have small ranges. Location Global. Methods We extensively surveyed museum collections, the primary literature and our own field records to identify all the species of lizards with a maximum linear geographic extent of <10 km. We compared their biogeography, key biological traits and threat status to those of all other lizards. Results One in seven lizards (927 of the 6,568 currently recognized species) are known only from their type localities. These include 213 species known only from a single specimen. Compared to more wide-ranging taxa, they mostly inhabit relatively inaccessible regions at lower, mostly tropical, latitudes. Surprisingly, we found that burrowing lifestyle is a relatively unimportant driver of small range size. Geckos are especially prone to having tiny ranges, and skinks dominate lists of such species not seen for over 50 years, as well as of species known only from their holotype. Two-thirds of these species have no IUCN assessments, and at least 20 are extinct. Main conclusions Fourteen per cent of lizard diversity is restricted to a single location, often in inaccessible regions. These species are elusive, usually poorly known and little studied. Many face severe extinction risk, but current knowledge is inadequate to properly assess this for all of them. We recommend that such species become the focus of taxonomic, ecological and survey efforts. [ABSTRACT FROM AUTHOR]

Age at sexual maturity is a central life-history parameter, strongly related to key traits such as body size and longevity. It is influenced by environmental and intrinsic factors that affect growth rates and gonad development. Using data on the age at sexual maturity in 123 species of amphibians worldwide, we tested whether sexual maturity is delayed at high altitudes and latitudes, in cold and dry regions and on islands. We further tested whether sexual maturity is delayed in species with parental care and direct development (no tadpole stage). Using phylogenetic regression and correcting for body size, we found a positive relationship between latitude and sexual maturity. Surprisingly, altitude was negatively correlated with sexual maturity in small species. Temperature was negatively related to sexual maturity in females but not in males. Precipitation and seasonality did not effect on either sex. Species that engage in parental care or have direct-developing larvae mature early. We found no effect of insularity, contradicting the insular syndrome hypothesis. Meta-analyses revealed that, within species, sexual maturity is reached at younger ages in warm temperatures in aseasonal environments and in low altitudes. Thus, although life-history strategies affect maturation time, climate can further delay or accelerate development - probably through effects on metabolic rates and season length.. [ABSTRACT FROM AUTHOR]

Aim Both theory and empirical data suggest that life histories of insular species slow down (the 'island syndrome'). Insular individuals are hypothesized to lay smaller clutches of larger eggs compared with individuals belonging to closely related mainland species. Most lizards have variable clutch sizes and can lay any number between one egg and a species-specific maximum which can be well over 50 eggs. Many lizards, such as geckos and anoles, however, lay invariant small clutches of one or two eggs, and may thus be unable to manifest some aspects of the island syndrome. We tested whether insular species with either variable or invariant clutch sizes respond to insularity differently. Location Worldwide. Methods We assembled data on egg, clutch, hatchling and female sizes and brood frequencies of 2,511 lizard species. We tested whether the predictions of the island syndrome were met for lizards laying invariant versus variable clutches, controlling for female size and phylogenetic non-independence. We further examined whether geckos and anoles, the major clades with invariant clutches, differ from other lizards in the way they respond to insularity. Results On islands, species with variable clutch sizes lay smaller clutches of larger eggs, from which larger hatchlings emerge, compared with mainland species. Lizards with invariant clutch sizes, however, decrease clutch size and increase clutch frequency but not hatchling or egg size, compared with mainland species. Main conclusions Lizards with invariant clutch sizes may be unable to increase egg and hatchling sizes because of limitations set by the female body cavity and pelvic opening, or by arboreality. They nonetheless lay smaller clutches on islands and increase clutch frequency. We suggest that this may result from lower seasonality of tropical islands, leading to a greater spread of reproductive effort. Alternatively, the higher clutch frequency on tropical islands could result from fluctuations in population densities caused by tropical storms. [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]

Aim Dietary niche breadth has long been hypothesized to decrease towards lower latitudes as the numbers of competitors increase. Geographical variation in niche breadth is also hypothesized to be linked to high ambient energy levels, water availability, productivity and climate stability - reflecting an increased number of available prey taxa. Range size and body size are also hypothesized to be strongly and positively associated with niche breadth. We sought to determine which of these factors is associated with geographical variation in niche breadth across broad spatial scales and thus potentially drive the latitudinal diversity gradient. Location Global. Methods We collated volumetric dietary data for 308 lizard species. For each species, we gathered data on number of sympatric lizard species (a proxy for the number of competitors), annual temperature and precipitation, net primary productivity, seasonality, range size and body size. We examined the relationship between dietary niche breadth and focal parameters using both ordinary and phylogenetic generalized least squares regressions. Results Niche breadth was positively related to annual precipitation, temperature seasonality and range size, and negatively related to body size. Lizard species richness increased towards lower latitudes. Dietary niche breadth, however, was unrelated to parameters reflecting diversity gradients, such as primary productivity, annual temperature, precipitation seasonality and, crucially, the number of potential competitors. Main conclusions Contrary to prevailing ecological theory, competition is unrelated to dietary niche breadth. We found no support for interspecific competition driving the latitudinal diversity gradient. Rather, we found variation in niche breadth to be associated with water availability, climate stability, range size and body size. Our study casts doubt on the common assumption that tropical species are specialists, promoting greater alpha diversity, and on the assumption that the number of sympatric species is reflected in the intensity of interspecific competition. [ABSTRACT FROM AUTHOR]

Reptiles represent the world's most diverse group of terrestrial vertebrates (~ 10,300 recognized species). Knowledge of their conservation status, however, lags behind that of birds, mammals and amphibians. Only ~ 40% of the world's reptile species have had their conservation status assessed by the IUCN, and detailed analysis of extinction risk has been limited to a subset of 1500 species. Using lizards (Sauria and Amphisbaenia), the most diverse group of reptiles, we investigated whether biases in distribution, ecology, life-history and taxonomy exist in the species that have been assessed to date by the IUCN. Our results highlight that only 36% of the ~ 6300 described lizard species have had their conservation status assessed. Whilst data deficiency is a key concern in lizards (16% of assessed species), the large number of non-assessed species (~ 4000 species) represents a larger and more pressing issue. Accentuating this ‘assessment gap’ is the fact that biases exist in the subset of lizard species that have been assessed by the IUCN. Australia and Asia, as well as tropical areas in general, were the least assessed regions. Assessed lizard species were more likely to have larger body and clutch sizes, broader distributional and elevational ranges, occur at more northerly latitudes, and have a viviparous mode of reproduction. Some evidence suggests that they also tend to be diurnal, surface active, and with developed limbs. The level of assessment also differed significantly among lizard families and higher taxa. We recommend the implementation of an integrated approach to bridge the ‘assessment gap’ in lizards, involving regional and taxon-specific working groups associated with the IUCN's Global Reptile Assessment, predictive modelling, enhanced knowledge of lizard distribution and biology, and improved taxonomic methods. [ABSTRACT FROM AUTHOR]

Reptiles are the most species-rich group of terrestrial vertebrates, yet we lack a comprehensive understanding of their extinction risk. Only 45% of described reptile species have been assessed by IUCN to date (4648 of 10,400 species); of these, 20% (945 species) are threatened with extinction, and 19% (867 species) are Data Deficient. The goal of this special issue is to improve our understanding of reptile conservation needs and extinction risk by (i) investigating patterns and drivers of extinction risk and data deficiency at a global scale; (ii) identifying and addressing taxonomic and regional gaps in our understanding of extinction risk and data deficiency; and (iii) drawing upon detailed case studies to highlight conservation approaches to mitigate extinction. By doing so, the special issue will guide future conservation efforts toward the taxa and regions in greatest need of assessment, and toward risks requiring immediate mitigation. We conclude with potential avenues for future research, including the need to address regional knowledge gaps, conduct macroecological and retrospective analyses of extinction risk, and implement targeted monitoring of conservation intervention outcomes. [ABSTRACT FROM AUTHOR]

Reptiles represent the world's most diverse group of terrestrial vertebrates (~ 10,300 recognized species). Knowledge of their conservation status, however, lags behind that of birds, mammals and amphibians. Only ~ 40% of the world's reptile species have had their conservation status assessed by the IUCN, and detailed analysis of extinction risk has been limited to a subset of 1500 species. Using lizards (Sauria and Amphisbaenia), the most diverse group of reptiles, we investigated whether biases in distribution, ecology, life-history and taxonomy exist in the species that have been assessed to date by the IUCN. Our results highlight that only 36% of the ~ 6300 described lizard species have had their conservation status assessed. Whilst data deficiency is a key concern in lizards (16% of assessed species), the large number of non-assessed species (~ 4000 species) represents a larger and more pressing issue. Accentuating this ‘assessment gap’ is the fact that biases exist in the subset of lizard species that have been assessed by the IUCN. Australia and Asia, as well as tropical areas in general, were the least assessed regions. Assessed lizard species were more likely to have larger body and clutch sizes, broader distributional and elevational ranges, occur at more northerly latitudes, and have a viviparous mode of reproduction. Some evidence suggests that they also tend to be diurnal, surface active, and with developed limbs. The level of assessment also differed significantly among lizard families and higher taxa. We recommend the implementation of an integrated approach to bridge the ‘assessment gap’ in lizards, involving regional and taxon-specific working groups associated with the IUCN's Global Reptile Assessment, predictive modelling, enhanced knowledge of lizard distribution and biology, and improved taxonomic methods. [ABSTRACT FROM AUTHOR]

Reptiles are the most species-rich group of terrestrial vertebrates, yet we lack a comprehensive understanding of their extinction risk. Only 45% of described reptile species have been assessed by IUCN to date (4648 of 10,400 species); of these, 20% (945 species) are threatened with extinction, and 19% (867 species) are Data Deficient. The goal of this special issue is to improve our understanding of reptile conservation needs and extinction risk by (i) investigating patterns and drivers of extinction risk and data deficiency at a global scale; (ii) identifying and addressing taxonomic and regional gaps in our understanding of extinction risk and data deficiency; and (iii) drawing upon detailed case studies to highlight conservation approaches to mitigate extinction. By doing so, the special issue will guide future conservation efforts toward the taxa and regions in greatest need of assessment, and toward risks requiring immediate mitigation. We conclude with potential avenues for future research, including the need to address regional knowledge gaps, conduct macroecological and retrospective analyses of extinction risk, and implement targeted monitoring of conservation intervention outcomes. [ABSTRACT FROM AUTHOR]

Aim Climate is thought to exert a strong influence on animal body sizes. We examined the relationship between amphibian body size and several climatic variables to discern which climatic variables, if any, affect amphibian size evolution. Location Europe and North America. Methods We assembled a dataset of mean sizes of 356 (out of 360) amphibian species in Europe, the USA and Canada, and tested how they are related to temperature, precipitation, primary productivity and seasonality. First, we examined the body size distributions of all the species inhabiting equal-area grid cells (of 96.3 km × 96.3 km) using randomizations to account for the effects of species richness. Second, we examined the relationship between mean species body size and the environmental predictors across their ranges accounting for phylogenetic effects. Results The observed amphibian body size distributions were mostly statistically indistinguishable from distributions generated by random assignment of species to cells. Median sizes in grid cells were negatively correlated with temperature in anurans and positively in urodeles. The phylogenetic analysis revealed opposite trends in relation to temperature. In both clades most climatic variables were not associated with size and the few significant relationships were very weak. Main conclusions Spatial patterns in amphibian body size probably reflect diversity gradients, and relationships with climate could result from spurious effects of richness patterns. The large explanatory power of richness in the grid-cell analysis, and the small explanatory power of climate in the interspecific analysis, signify that climate per se has little effect on amphibian body sizes. [ABSTRACT FROM AUTHOR]

Sexual size dimorphism ( SSD) can allow males and females of the same species to specialize on different sized food items and therefore minimize intraspecific competition., Interspecific competition, however, is thought to limit sexual dimorphism, as larger competitors in the community will prevent the larger sex from evolving larger size, and smaller species may prevent the smaller sex from becoming even smaller., We tested this prediction using data on the sexual size dimorphism of lizards, and mammalian carnivores, on islands world-wide., Because insular communities are depauperate, and guilds are species-poor, it is often assumed that enhanced sexual size dimorphism is common on islands. The intensity of interspecific competition, hindering enhanced dimorphism, is thought to increase with competitor richness., We tested whether intraspecific sexual size dimorphism of mammalian carnivores and lizards decreases with increasing island species richness. We further computed the average sexual dimorphism of species on islands and tested whether species-rich islands are inhabited by relatively monomorphic species. Within families and guilds across carnivores and lizards, and with both intraspecific and interspecific approaches, we consistently failed to find support for the notion that species-poor islands harbour more sexually dimorphic individuals or species., We conclude that either interspecific competition does not affect the sexual size dimorphism of insular lizards and carnivores (i.e. character displacement and species sorting are rare in these taxa), or that the number of species in an assemblage or guild is a poor proxy for the intensity of interspecific competition in insular assemblages. [ABSTRACT FROM AUTHOR]

Aim The origins of islands influence island colonization and radiation dynamics, thus exerting differential selection pressures on the species that inhabit them. The occurrence of lower numbers of predator and competitor species on islands than the mainland selects for 'slow' life-history attributes (the 'island syndrome'). Animals colonizing, and radiating on, oceanic islands probably face more novel environments than do those inhabiting continental fragment and land-bridge islands. We hypothesized that oceanic island endemics will show the slowest life histories, whereas land-bridge island species will resemble mainland species the most. We predicted that species on old, small and isolated islands will also have slow life histories. Location World-wide. Methods We assembled life-history data for 540 mainland and 319 insular endemic lizard species. We tested whether clutch size, brood frequency, hatchling mass and productivity differed between islands of different origin and between islands and the mainland. We controlled for female size, for latitude and for phylogenetic relationship using the R package caper. In addition, we tested the influences of island age, area and isolation on species life histories. Results Oceanic island endemics have the smallest clutches and the largest offspring, and, together with continental fragment island endemics, lay most frequently. Clutch size, brood frequency and productivity increase with increasing island age. Isolation and area have little effect on lizard life history. Main conclusions Our findings support the proposition that selection pressure differs across island type. The predator-poor environments on oceanic islands select for few, large offspring, while the predator-rich environments of the mainland and land-bridge islands select for many, small offspring. Island geological origin creates the environment within which evolution takes place, and thus plays a major role in life-history evolution. As islands grow older, lizards adapt by increasing their yearly reproductive effort. [ABSTRACT FROM AUTHOR]

Sexual-size dimorphism ( SSD) is widespread in animals. Body length is the most common trait used in the study of SSD in reptiles. However, body length combines lengths of different body parts, notably heads and abdomens. Focusing on body length ignores possible differential selection pressures on such body parts. We collected the head and abdomen lengths of 610 lizard species ( Reptilia: Squamata: Sauria). Across species, males have relatively larger heads, whereas females have relatively larger abdomens. This consistent difference points to body length being an imperfect measure of lizard SSD because it comprises both abdomen and head lengths, which often differ between the sexes. We infer that female lizards of many species are under fecundity selection to increase abdomen size, consequently enhancing their reproductive output (enlarging either clutch or offspring size). In support of this, abdomens of lizards laying large clutches are longer than those of lizards with small clutches. In some analyses, viviparous lizards have longer abdomens than oviparous lizards with similar head lengths. Our data also suggest that male lizards are under sexual selection to increase head size, which is positively related to winning male-male combats and to faster grasping of females. Thus, larger heads could translate into higher probability to mate. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 665-673. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hair-pulling was expressed by 75% of the species. [•] Pacing was expressed by 50% of the species. [•] Hair-pulling levels were positively correlated with group size. [•] Pacing levels were positively correlated with day journey lengths. [Copyright &y& Elsevier]

Aim Temperature influences most components of animal ecology and life history - but what kind of temperature? Physiologists usually examine the influence of body temperatures, while biogeographers and macroecologists tend to focus on environmental temperatures. We aim to examine the relationship between these two measures, to determine the factors that affect lizard body temperatures and to test the effect of both temperature measures on lizard life history. Location World-wide. Methods We used a large (861 species) global dataset of lizard body temperatures, and the mean annual temperatures across their geographic ranges to examine the relationships between body and mean annual temperatures. We then examined factors influencing body temperatures, and tested for the influence of both on ecological and life-history traits while accounting for the influence of shared ancestry. Results Body temperatures and mean annual temperatures are uncorrelated. However, accounting for activity time (nocturnal species have low body temperatures), use of space (fossorial and semi-aquatic species are 'colder'), insularity (mainland species are 'hotter') and phylogeny, the two temperatures are positively correlated. High body temperatures are only associated with larger hatchlings and increased rates of biomass production. Annual temperatures are positively correlated with clutch frequency and annual longevity, and negatively correlated with clutch size, age at first reproduction and longevity. Main conclusions Lizards with low body temperatures do not seem to have 'slower' life-history attributes than species with high body temperatures. The longer seasons prevalent in warm regions, and physiological processes that operate while lizards are inactive (but warm enough), make environmental temperatures better predictors of lizard life-history variation than body temperatures. This surprisingly greater effect of environmental temperatures on lizard life histories hints that global warming may have a profound influence on lizard ecology and evolution. [ABSTRACT FROM AUTHOR]

Abstract: Body size shapes the overall biology of organisms. We assessed the impact of size on temperature regulation in populations of normal-sized and large-bodied insular Mediterranean lizards (Podarcis gaigeae, Lacertidae). We hypothesized that large lizards would achieve higher body temperatures and thermoregulate more effectively than their smaller kin. Large- and small-bodied lizards share the same thermoregulation pattern, achieving similar body temperatures in the field. Large lizards, however, prefer higher set-point temperatures. Lizards in both populations thermoregulate effectively, but large lizards thermoregulated less effectively than normal-sized lizards. The particular conditions at the islet that harbors the large-bodied population (harsh intraspecific competition) seem to account for this pattern. [Copyright &y& Elsevier]

Body size and body shape are tightly related to an animal's physiology, ecology and life history, and, as such, play a major role in understanding ecological and evolutionary phenomena. Because organisms have different shapes, only a uniform proxy of size, such as mass, may be suitable for comparisons between taxa. Unfortunately, snake masses are rarely reported in the literature. On the basis of 423 species of snakes in 10 families, we developed clade-specific equations for the estimation of snake masses from snout-vent lengths and total lengths. We found that snout-vent lengths predict masses better than total lengths. By examining the effects of phylogeny, as well as ecological and life history traits on the relationship between mass and length, we found that viviparous species are heavier than oviparous species, and diurnal species are heavier than nocturnal species. Furthermore, microhabitat preferences profoundly influence body shape: arboreal snakes are lighter than terrestrial snakes, whereas aquatic snakes are heavier than terrestrial snakes of a similar length. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ●●, ●●-●●. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim We provide a new quantitative analysis of lizard reproductive ecology. Comparative studies of lizard reproduction to date have usually considered life-history components separately. Instead, we examine the rate of production (productivity hereafter) calculated as the total mass of offspring produced in a year. We test whether productivity is influenced by proxies of adult mortality rates such as insularity and fossorial habits, by measures of temperature such as environmental and body temperatures, mode of reproduction and activity times, and by environmental productivity and diet. We further examine whether low productivity is linked to high extinction risk. Location World-wide. Methods We assembled a database containing 551 lizard species, their phylogenetic relationships and multiple life history and ecological variables from the literature. We use phylogenetically informed statistical models to estimate the factors related to lizard productivity. Results Some, but not all, predictions of metabolic and life-history theories are supported. When analysed separately, clutch size, relative clutch mass and brood frequency are poorly correlated with body mass, but their product - productivity - is well correlated with mass. The allometry of productivity scales similarly to metabolic rate, suggesting that a constant fraction of assimilated energy is allocated to production irrespective of body size. Island species were less productive than continental species. Mass-specific productivity was positively correlated with environmental temperature, but not with body temperature. Viviparous lizards were less productive than egg-laying species. Diet and primary productivity were not associated with productivity in any model. Other effects, including lower productivity of fossorial, nocturnal and active foraging species were confounded with phylogeny. Productivity was not lower in species at risk of extinction. Main conclusions Our analyses show the value of focusing on the rate of annual biomass production (productivity), and generally supported associations between productivity and environmental temperature, factors that affect mortality and the number of broods a lizard can produce in a year, but not with measures of body temperature, environmental productivity or diet. [ABSTRACT FROM AUTHOR]

The tempo andmode of body size evolution on islands are believed to be well known. It is thought that body size evolves relatively quickly on islands toward the mammalian modal value, thus generating extreme cases of size evolution and the island rule. Here, we tested both theories in a phylogenetically explicit context, by using two different species-level mammalian phylogenetic hypotheses limited to sister clades dichotomizing into an exclusively insular and an exclusively mainland daughter nodes. Taken as a whole, mammals were found to show a largely punctuational mode of size evolution. We found that, accounting for this, and regardless of the phylogeny used, size evolution on islands is no faster than on the continents. We compared different selection regimes using a set of Ornstein-Uhlenbeck models to examine the effects of insularity of the mode of evolution. The models strongly supported clade-specific selection regimes. Under this regime, however, an evolutionary model allowing insular species to evolve differently from their mainland relatives performs worse than a model that ignores insularity as a factor. Thus, insular taxa do not experience statistically different selection from their mainland relatives. [ABSTRACT FROM AUTHOR]

Competition is thought to be a major influence on community assembly, ecology and evolution; presence of competitors may cause divergence in traits related to resource use (character displacement). Such traits, however, often vary clinally, and this phenomenon may be independent of the presence or absence of competing species. The presence of such clines can either obscure the effects of competition, or create an impression that competition is operating when, in fact, it is not. We corrected for clinal variation while testing for character displacement in two well-studied weasel ( Mustela) guilds, in the Nearctic and the west Palaearctic. Without accounting for clines, our results agreed with previous studies suggesting character displacement in these guilds. However, when we corrected for clines, predictions of competition theory were not met - and often we obtained evidence for character convergence in sympatry. This may suggest that the nature of the resource base may be more important than interspecific competition in shaping morphology and size in these carnivores. Our results highlight the need to account for geographic variation when studying character displacement and cast some doubt on prevailing ideas regarding the effect of competition on morphological evolution. [ABSTRACT FROM AUTHOR]