Lacertid Species Research Articles

Analysis of subcellular energy metabolism in five Lacertidae lizards across varied environmental conditions

Aerobic respiration is the main energy source for most eukaryotes, and efficient mitochondrial energy transfer greatly influences organismal fitness. To survive environmental changes, cells have evolved to adjust their biochemistry. Thus, measuring energy metabolism at the subcellular level can enhance our understanding of individual performance, population dynamics, and species distribution ranges. We investigated three important metabolic traits at the subcellular level in five lacertid lizard species sampled from different elevations, from sea level up to 2000 m. We examined hemoglobin concentration, two markers of oxidative stress (catalase activity and carbonyl concentration) and maximum rate of metabolic respiration at the subcellular level (potential metabolic activity at the electron transport system). The traits were analysed in laboratory acclimated adult male lizards to investigate the adaptive metabolic responses to the variable environmental conditions at the local sampling sites. Potential metabolic activity at the cellular level was measured at four temperatures – 28 °C, 30 °C, 32 °C and 34 °C – covering the range of preferred body temperatures of the species studied. Hemoglobin content, carbonyl concentration and potential metabolic activity did not differ significantly among species. Interspecific differences were found in the catalase activity, Potential metabolic activity increased with temperature in parallel in all five species. The highest response of the metabolic rate with temperature (Q10) and Arrhenius activation energy (Ea) was recorded in the high-mountain species Iberolacerta monticola.

Systematics and distribution of the genus Darevskia Arribas, 1997 on the Iranian plateau: a review

Two hundred ninety species of lacertids are presently placed in from 24 to about 30 genera. Most of the genera that have been recognized appear to be clades on the basis of their morphology, with the exception of the paraphyletic central African Adolfus and Lacerta sensu lato of Europe, Asia and northwest Africa. Traditionally, species boundaries are only based on morphological and appearance differences, and this approach is qualitatively or quantitatively investigated. At the same time, several new and modern methods can be used for a more realistic and logical investigation in the determination of species boundaries. Molecular analysis has provided more evidence about lacertids' kinship relationships. These methods work particularly well when dealing with cryptic species or species complexes. Where there is a high general and morphological similarity between the species of a population. The rock lizards, genus Darevskia Arribas, 1999, are such species, as many of its members have few distinctive and diagnostic morphological features. Biodiversity and species diversity assessment allows for more precise determination of the causes of many biological processes. These processes involve complex patterns that are especially observed in areas with high species diversity. Anatolia and Caucasus regions are two important geographical regions where Darevskia species live, which have complex morphology and unique speciation. Darevskia valentini and D. rudis are two widely distributed species of this genus, both of which have controversial taxonomy. In this study, an attempt has been made to summarize the species available in Iran.

Social display in the Curaçao Whiptail (Cnemidophorus murinus Laurenti)

Three teiid species (Squamata: Teiidae) are endemic to the ABC islands (Aruba, Bonaire, and Curaçao) of the former Netherlands Antilles: the Aruba Whiptail (Cnemidophorus arubensis) of Aruba, the Bonaire Whiptail (C. ruthveni) of Bonaire and Klein-Bonaire, and the Curaçao Whiptail (C. murinus) of Curaçao and Klein-Curaçao. Before now, social displays have been described only for one of these three species: C. ruthveni (Baird et al. 2003). All three species engage in an arm-waving display that involves forelimb circumduction (Baird et al. 2003; van Buurt 2005; van Buurt 2011), which conveys social signals to conspecifics in some iguanian and lacertid lizard species (Carpenter et al. 1970; Verbeek 1972; Mitchell 1973). However, this behavior in the ABC island species of Cnemidophorus has not been shown to have a social function (Baird et al. 2003). Instead, experimental evidence demonstrates that in C. ruthveni it functions as a pursuit deterrent display that is performed in response to approaching humans, whom the lizard may view as potential predators (Cooper et al. 2004), although there are not yet any published reports of C. ruthveni performing the display in response to the approach of a non-human predator. My observations and those of others (van Buurt 2011) also confirm that in C. arubensis the display is performed in response to approaching humans.

Climate-driven mitochondrial selection in lacertid lizards.

The mitochondrion, which is an intracellular organelle responsible for most of the energy-producing pathways, can have its genome targeted for climate-driven selection. However, climate-driven mitochondrial selection remains a sparsely studied area in reptiles. Here, we reported the complete mitochondrial genome sequence of a lacertid lizard (Takydromus intermedius) and used mitogenomes from 54 species of lacertid lizards to study their phylogenetic relationships and to identify the mitochondrial genes under positive selection by climate. The length of the complete mitochondrial genome sequence of T. intermedius was 17,713 bp, which was within the range of lengths (17,224-18,943) ever reported for Takydromus species. The arrangement of mitochondrial genes in T. intermedius was the same as in other congeneric species. The 54 lacertid species could be divided into three geographically and climatically different clades. We identified three mitochondrial genes (ATP6, ATP8, and ND3) under positive selection by climate, and found that isothermality, temperature seasonality, precipitation of wettest month, and precipitation seasonality were the most important climatic variables contributing to the gene selection.

Habitat turnover in Iberian and Italian lizards: Is it climatically, spatially, or phylogenetically determined?

AbstractThe Mediterranean peninsulas host rich assemblages of lizards, but little is known about the factors that limit their habitat use on large spatial scales. In this study, we investigated the variation in habitat use of 29 species of lacertid lizards on the Iberian and Italian peninsulas and the transitional region of southeastern France. We investigated whether the types of habitat used were phylogenetically determined or, in contrast, were more influenced by spatial or climatic effects. We characterized the vegetal composition of 483 habitats used by lacertids and estimated the contribution of each component to habitat variability using distance‐based redundancy analysis. We showed that overall turnover patterns were determined similarly in both peninsulas, despite differences in the composition of the lacertid assemblages. The aridity‐related component dominated over the phylogenetic one, which has a weak influence in both regions. The species showed different turnover patterns, being low in those present in cold alpine habitats and shrub‐steppe specialists. In some Iberian endemics, habitat turnover occurs within relatively homogeneous climatic bands. However, in the Italian species, habitat turnover has a comparatively stronger climatic component, suggesting lower climatic specialization. This study shows that species distributions across habitats provide information to assess community properties and can be applied to explore differences among faunal assemblages over large geographic areas. Our results provide evidence that beta diversity can play a key role in structuring patterns of habitat turnover.

Sexual Selection and Proteinaceous Diversity in the Femoral Gland Secretions of Lacertid Lizards

Sexual selection contributes to the diversity of chemical signals in various animal groups. Lizards are good model species to study how sexual selection shapes signal diversity, as they are a chemically oriented taxonomic group with different levels of social interactions. Many lizard species bear epidermal glands secreting a waxy mixture of lipids and proteins, which are used in intraspecific communication. Previous among-species comparative analyses failed to find a relationship between the strength of sexual selection with the composition of the lipid blend in lizards. Here, we extend the investigation to the proteinaceous fraction. By using a phylogenetically informed approach, we correlated the average electrophoretic profiles of the protein from the femoral glands of 36 lacertid lizard species with the level of sexual dimorphism in size and shape, which are proxies for the strength of sexual selection. We found that as sexual size dimorphism advances, five distinct molecular weight regions in the protein profile increased their expression. Using tandem mass spectrometry, we successfully identified one of these five proteins: a carbonic anhydrase—an enzyme catalyzing the reversible hydration of carbon dioxide. Our findings suggest that proteins may be the target of sexual selection, as an active semiochemicals or as a dynamic support to other molecules: sexual selection may act indirectly on semiochemicals (namely lipids) by modifying the matrix (namely proteins).

Is Fluctuating Asymmetry a Sufficient Indicator of Stress Level in Two Lizard Species (Zootoca vivipara and Lacerta agilis) from Alpine Habitats?

Alpine habitats are exposed to increasing anthropogenic pressure and climate change. The negative impacts can lead to chronic stress that can affect the survival and reproductive success of individuals and even lead to population extinction. In this study, we analyse different morphological and ecological traits and indices of abiotic and biotic stressors (such as head size and shape, fluctuating asymmetry, body condition index, tail autotomy, and population abundance) in alpine and subalpine populations of two lacertid species (Zootoca vivipara and Lacerta agilis) from Serbia and North Macedonia. These lizards live under different conditions: allotopy/syntopy, different anthropogenic pressure, and different levels of habitat protection. We found differences between syntopic and allotopic populations in pileus size, body condition index (in both species), pileus shape, fluctuating asymmetry (in L. agilis), and abundance (in Z. vivipara). Differences between populations under anthropogenic pressure and populations without it were observed in pileus shape, body condition index (in both species), pileus size, fluctuating asymmetry, tail autotomy and abundance (in L. agilis). On the basis of our results, it is necessary to include other stress indicators in addition to fluctuating asymmetry to quickly observe and quantify the negative effects of threat factors and apply protective measures.

Selected microhabitat and surface temperatures of two sympatric lizard species

Many small lizards live in structurally and thermally heterogeneous environments where they can select preferred microhabitats and surface temperatures to optimize their activity. We examined microhabitat selection and analyzed surface temperatures selected by two ecologically similar lacertid species, Iberolacerta horvathi and Podarcis muralis, at three sites and in different ecological contexts: allotopic and syntopic conditions. We examined their microhabitat and spatial thermal selection by using high-precision geolocation techniques to locate the lizards and record surface temperatures with temperature data loggers. Microhabitat and thermal availability differed among sites: the I. horvathi allotopic site had more rock surfaces and was coldest; the P. muralis allotopic site had more ground surfaces and was warmer; and the syntopic site had the greatest surface and thermal heterogeneity. Our results highlight the differences in microhabitat selection between the two species, most notably in surface selection, but also in thermal characteristics. I. horvathi preferentially and almost exclusively selected rocks. P. muralis chose soil, but with a more general use of microhabitats. I. horvathi lizards chose colder temperatures than those available, while P. muralis chose higher temperatures than those available. Both species showed no differences in microhabitat selection between allotopic and syntopic sites, which could not be explained by differences between sites. Our results provided new insights into the difference in surface temperature selection between two lizard species that may be adapted to different environments.

Learning with lacertids: Studying the link between ecology and cognition within a comparative framework.

Cognition is an essential tool for animals to deal with environmental challenges. Nonetheless, the ecological forces driving the evolution of cognition throughout the animal kingdom remain enigmatic. Large-scale comparative studies on multiple species and cognitive traits have been advanced as the best way to facilitate our understanding of cognitive evolution, but such studies are rare. Here, we tested 13 species of lacertid lizards (Reptilia: Lacertidae) using a battery of cognitive tests measuring inhibitory control, problem-solving, and spatial and reversal learning. Next, we tested the relationship between species' performance and (a) resource availability (temperature and precipitation), habitat complexity (Normalized Difference Vegetation Index), and habitat variability (seasonality) in their natural habitat and (b) their life history (size at hatching and maturity, clutch size, and frequency). Although species differed markedly in their cognitive abilities, such variation was mostly unrelated to their ecology and life history. Yet, species living in more variable environments exhibited lower behavioral flexibility, likely due to energetic constrains in such habitats. Our standardized protocols provide opportunities for collaborative research, allowing increased sample sizes and replication, essential for moving forward in the field of comparative cognition. Follow-up studies could include more detailed measures of habitat structure and look at other potential selective drivers such as predation.

Functional genomics of abiotic environmental adaptation in lacertid lizards and other vertebrates.

Understanding the genomic basis of adaptation to different abiotic environments is important in the context of climate change and resulting short-term environmental fluctuations. Using functional and comparative genomics approaches, we here investigated whether signatures of genomic adaptation to a set of environmental parameters are concentrated in specific subsets of genes and functions in lacertid lizards and other vertebrates. We first identify 200 genes with signatures of positive diversifying selection from transcriptomes of 24 species of lacertid lizards and demonstrate their involvement in physiological and morphological adaptations to climate. To understand how functionally similar these genes are to previously predicted candidate functions for climate adaptation and to compare them with other vertebrate species, we then performed a meta-analysis of 1,100 genes under selection obtained from -omics studies in vertebrate species adapted to different abiotic factors. We found that the vertebrate gene set formed a tightly connected interactome, which was to 23% enriched in previously predicted functions of adaptation to climate, and to a large part (18%) involved in organismal stress response. We found a much higher degree of identical genes being repeatedly selected among different animal groups (43.6%), and of functional similarity and post-translational modifications than expected by chance, and no clear functional division between genes used for ectotherm and endotherm physiological strategies. In total, 171 out of 200 genes of Lacertidae were part of this network. These results highlight an important role of a comparatively small set of genes and their functions in environmental adaptation and narrow the set of candidate pathways and markers to be used in future research on adaptation and stress response related to climate change.

How to Render Species Comparable Taxonomic Units Through Deep Time: A Case Study on Intraspecific Osteological Variability in Extant and Extinct Lacertid Lizards.

Generally, the species is considered to be the only naturally occurring taxon. However, species recognized and defined using different species delimitation criteria cannot readily be compared, impacting studies of biodiversity through Deep Time. This comparability issue is particularly marked when comparing extant with extinct species because the only available data for species delimitation in fossils are derived from their preserved morphology, which is generally restricted to osteology in vertebrates. Here, we quantify intraspecific, intrageneric, and intergeneric osteological variability in extant species of lacertid lizards using pairwise dissimilarity scores based on a data set of 253 discrete osteological characters for 99 specimens referred to 24 species. Variability is always significantly lower intraspecifically than between individuals belonging to distinct species of a single genus, which is in turn significantly lower than intergeneric variability. Average values of intraspecific variability and associated standard deviations are consistent (with few exceptions), with an overall average within a species of 0.208 changes per character scored. Application of the same methods to six extinct lacertid species (represented by 40 fossil specimens) revealed that intraspecific osteological variability is inconsistent, which can at least in part be attributed to different researchers having unequal expectations of the skeletal dissimilarity within species units. Such a divergent interpretation of intraspecific and interspecific variability among extant and extinct species reinforces the incomparability of the species unit. Lacertidae is an example where extant species recognized and defined based on a number of delimitation criteria show comparable and consistent intraspecific osteological variability. Here, as well as in equivalent cases, application of those skeletal dissimilarity values to paleontological species delimitation potentially provides a way to ameliorate inconsistencies created by the use of morphology to define species. [Intraspecific variation; Lacertidae; morphological disparity; osteology; species delimitation; taxonomic bias.].

Mid-Pleistocene Transition as a trigger for diversification in the Irano-Anatolian region: Evidence revealed by phylogeography and distribution pattern of the eastern three-lined lizard

Past climatic events are one of the major drivers for divergence of species that could shape the present biodiversity and species dispersal patterns. Irano-Anatolian region is one of the biodiversity hotspots in the world. This region is predicted to serve various refugia during Quaternary glaciations. The eastern three-lined lizard ( Lacerta media media ) is a medium-sized lacertid species, which is originated from central Anatolian and is currently distributed almost across Irano-Anatolian region. In this study, the phylogeography, demographic history of the subspecies using mtDNA genes (cyt b , 12S and 16S) along with the species distribution models (SDMs) under past-present-future scenarios have been investigated. The results revealed that four distinct clades are well-established within the L. m. media which may intensely diverge during Pleistocene climatic fluctuations since the Mid-Pleistocene Transition (MPT). The past climate oscillations may isolate the population in various refugia throughout the Irano-Anatolian region which has been led to this divergence. The results of SDMs also indicates several localities with suitable climate conditions for eastern three-lined lizard in the region since LGM (21 thousand years ago) until the current date. This suitability can be expanded under future climate scenarios considering the existence of various low and high altitude refugia. Some conservation implications arise from the results that emphasize the importance of the region and its multiple refugia in preserving biodiversity. It can be suggested that, future conservation practices should be focused on the obtained biogeographical units such as central Anatolia, west and northwestern Iran, which encompass high levels of diversity including distinct clades within the eastern three-lined lizard.

Phylogenetic value of jaw elements of lacertid lizards (Squamata: Lacertoidea): a case study with Oligocene material from France.

Several extinct species are known from the family Lacertidae, but due to poor preservation, many of them are based on single bones. Here, we compare phylogenetic signals of disarticulated premaxillae, maxillae and dentaries of lacertids from four French Oligocene localities (Coderet, La Colombière, Roqueprune 2, Mas de Got B). We identified five morphotypes among the premaxillae, six among the maxillae, and ten among the dentaries. These morphotypes were scored as individual taxa per locality into three separate character matrices with the same 246 characters, one matrix for each jaw element. Subsequently, the phylogenetic position of the morphotypes was tested using maximum parsimony. The consensus trees with the dentaries and the maxillae found a large polytomy including all taxa except the outgroup taxon Gekko gecko. The consensus tree with the premaxillae showed a considerably more resolved topology but found all morphotype taxa outside Lacertidae. In a second step, we compared the constitution of our three datasets and the morphotype taxa. Our results suggest that a combination of convergent characters and missing data led to the outgroup position of the premaxilla morphotype taxa. The poor resolution of the maxillae strict consensus is likely a consequence of their fragmentary preservation. For the dentaries, a high amount of missing data due to the high number of morphotype taxa most likely caused the poor tree resolution. Indeed, tests with fewer morphotypes found tree resolutions comparable to the premaxilla data. When linking the morphotypes, five possible lacertid "species" were found. Comparison with already known French Oligocene lacertid species points to a slightly higher species richness of Lacertidae at that time than known before. Reliable species classification based on phylogeny only seems possible when combining the jaw elements or in association with other cranial and postcranial material, putting some doubt on species identifications based on single bones.

Pleistocene climate fluctuations as the major driver of genetic diversity and distribution patterns of the Caspian green lizard, Lacerta strigata Eichwald, 1831.

Green lizards of the genus Lacerta have served as excellent models for studying the impact of Pleistocene climatic oscillations on genetic structures. The Caspian green lizard, Lacerta strigata, occupies various habitats across the Caucasus and the South Caspian Sea, with the Hyrcanian Forests and north of the Alborz Mountains forming the core of the range. This study aimed to re‐examine the phylogenetic relationships of L. strigata with other congeneric members and to assess the genetic structure and historical demography of the species. Furthermore, Species Distribution Models (SDMs) were performed to infer the species' potential habitat suitability and were then projected on climate scenarios reflecting current and past (6 ky and 21 ky before present) conditions. A total of 39 individuals collected from most of the distribution range, together with additional lacertid species sequences from the GenBank database, were examined using mtDNA (Cyt b and 12S ribosomal RNA) and nuclear (C‐mos and β‐fibrinogen) sequence data. Based on the phylogenetic analyses, L. strigata was found to be a sister taxon to all other members of the genus. The species included two main clades (regional western and eastern) that diverged in a period between the Early and Middle Pleistocene. Based on the BBM and S‐Diva analyses, both dispersal and vicariance events explained the phylogeographic structure of the species in the Hyrcanian Forests. The historical demographic analyses using Bayesian skyline plots showed a mild increase in the effective population size from about 120 Kya for the western regional clade. According to phylogeographic structures and SDMs evidence, as in other species within the region, it appears that the south of the Caspian Sea (Hyrcanian Forests), and the Alborz Mountains acted as multiple refugia during cold periods and promoted expansion outwards amid the warm periods. Overall, the results provided evidence that the genetic structure of the species has been influenced by the Pleistocene climatic fluctuations.

Osteological atlas of new lizards from the Phosphorites du Quercy (France), based on historical, forgotten, fossil material

A long-forgotten, old collection of lizards from the Phosphorites du Quercy in southern France, housed in the Naturhistorisches Museum in Vienna (NHMW), is described in detail in this paper. The material, consisting of several almost complete cranial and postcranial disarticulated elements, originates from different, imprecisely known localities. Nevertheless, the completeness and exceptional preservation of many of these specimens permitted the identification of new taxa, as well as the recognition and better understanding of novel anatomical features of previously described forms. Among the specimens, the material described herein and referred to Cadurcogekko cf. piveteaui ranks among the most complete cranial remains of Paleogene gekkotans. A clarification about the type material of the previously described species Cadurcogekko verusBolet, Daza, Augé & Bauer, 2015, is provided. A new species of lacertids is established, Pseudeumeces kyrillomethodicus n. sp. Additional, large lacertid material is referred to Mediolacerta Augé, 2005, representing also the largest one attributable to this genus. At least two glyptosaurine taxa are present in this collection, among which, the genus ParaplacosauriopsAugé & Sullivan, 2006, is represented by exceptional cranial material, referred to Paraplacosauriops quercyi (Filhol, 1882). The completeness of the cranial material of Paraplacosauriops permits a more comprehensive understanding of its maxillary and mandibular anatomy. A detailed documentation of cranial and postcranial material for the genus PalaeovaranusZittel, 1887-1890, is conducted. The new maxilla described herein allows a better understanding of the peculiar maxillary features of the genus Palaeovaranus. Emended diagnoses are provided for the genus Palaeovaranus and its type species Palaeovaranus cayluxiZittel, 1887-1890. The parietal morphology of Palaeovaranus is analyzed in detail and intraspecific variation in this element is assessed. A new species of Palaeovaranus is established, Palaeovaranus lismonimenos n. sp., on the basis of an almost complete parietal that can be differentiated from that of Palaeovaranus cayluxi on the basis of a number of distinctive features. Additional, previously published specimens from Quercy are here referred to Palaeovaranus lismonimenos n. sp., representing younger individuals of this species, and photographs of this material is provided for the first time. The diversity of platynotans in the Paleogene of Europe is discussed and their distinction on the basis of parietal morphology is provided. According to the new emended diagnosis for Palaeovaranus, the genus Melanosauroides Kuhn, 1940, is revalidated herein to accommodate Melanosauroides giganteus Kuhn, 1940, from the late early or middle Eocene of Geiseltal, Germany. So far, Melanosauroides giganteus is solely known from its type area in Geiseltal, and all previously supposed occurrences of this taxon in Quercy are discarded. Abundant anguimorph vertebral material is referred to Placosaurus sp., Melanosaurini indet., Anguinae indet., Palaeovaranus sp., Saniwa sp., and Anguimorpha indet., although it is highlighted that certain of these referrals should be taken into consideration with caution. Especially, the problem of certain large isolated lizard vertebrae from Quercy is addressed; a tentative, potential distinction between vertebrae of the genera Palaeovaranus and PlacosaurusGervais, 1848-1852, is suggested, although admittedly only articulated skeletons of these genera may confirm or refute such taxonomic referrals. The importance of fossil squamates from the area of the Phosphorites du Quercy is highlighted. Detailed figuring of the specimens is provided through the means of both photography and micro-CT scanning, with 3D models of the most significant material also presented. This is the first time that micro-CT scanning is conducted on fossil squamates from Quercy. The many figures provided in this paper may serve as a pictorial key guide for fossil lizards from the Paleogene of Europe.

Habitat Partitioning and Overlap by Large Lacertid Lizards in Southern Europe

South-western Europe has a rich diversity of lacertid lizards. In this study, we evaluated the occupancy patterns and niche segregation of five species of lacertids, focusing on large-bodied species (i.e., adults having >75 mm snout-vent length) that occur in south-western Europe (Italian to the Iberian Peninsula). We characterized the niches occupied by these species based on climate and vegetation cover properties. We expected some commonality among phylogenetically related species, but also patterns of habitat segregation mitigating competition between ecologically equivalent species. We used multivariate ordination and probabilistic methods to describe the occupancy patterns and evaluated niche evolution through phylogenetic analyses. Our results showed climate niche partitioning, but with a wide overlap in transitional zones, where segregation is maintained by species-specific responses to the vegetation cover. The analyses also showed that phylogenetically related species tend to share large parts of their habitat niches. The occurrence of independent evolutionary lineages contributed to the regional species richness favored by a long history of niche divergence.

Genetic diversity of Horvath’s Rock Lizard meets current environmental restrictions

The Horvath’s rock lizard Iberolacerta horvathi (Mehely, 1904) is an understudied lacertid species, which is geographically isolated from its congeners and currently classified as Near Threatened under IUCN red listing criteria. Due to its limited distribution and narrow environmental preferences, we expect that the species had been affected by past climatic oscillations. By combining all available data on species occurrences and our own records, we produced an updated distribution map. We used ecological niche models to identify the current environmental factors underlying the species range and developed a habitat suitability map. We sequenced one mitochondrial and one nuclear marker to characterize the distribution of the genetic variability and infer the historical demography of the species. The habitat suitability map identified areas where targeted field searches should be prioritized, as well as unsuitable habitats coinciding with likely barriers to gene flow. We found considerable genetic variability suggesting that the species probably survived the Pleistocene glaciations in at least two main refugia, one in the South and the other in the central/northern portion of its distribution. While southern populations show a moderate demographic decrease starting at the onset of the Eemian interglacial, the northern populations underwent an expansion during Late Pleistocene. We provide a revised species distribution and a first characterization of its genetic variability across its distribution to guide conservation priorities for this endemic and spatially restricted species.

Ecophysiology of a lacertid community in the high Moroccan mountains suggests conservation guidelines.

Lizard species may differ in their ecophysiology due to adaptation, plasticity and/or phylogeny. In restrictive environments, ecophysiological differences of species living in sympatry are expected to reveal long-term evolutionary responses to the abiotic environment while competitive interactions should be limited. These influences can be disentangled by combining field monitoring with experimental tests. Here, three lacertid lizard species, Atlantolacerta andreanskyi, Scelarcis perspicillata and Podarcis vaucheri sharing high mountain habitats in Oukaimeden (High Atlas, Morocco), were studied. In the field, spatiotemporal variation of the thermal and hydric environment used by the lizards was monitored using data-loggers. In the lab, thermal and hydric ecophysiology was estimated through assessments of preferred temperatures (Tp) and water loss (WL) rates. Species differed in microhabitat use and, hence, in their exposure to variations in temperature and humidity. However, they only differed in their WL (A. andreanskyi>S. perspicillata>P. vaucheri) while their Tp were similar. Such partial differences of species in in the fundamental niche, likely derived from their long-term independent phylogenetic trajectories, can be used to predict their responses to climate and habitat shifts in this and other parts of their respective ranges. Results also confirm previous suggestions that, together with thermal physiology, hydric physiology plays a prominent role in the organisation of lizard communities in the temperate region.

Skeletal Osteology of the Lacertid Lizards <i>Phoenicolacerta laevis</i> (Gray, 1838) and <i>Phoenicolacerta cyanisparsa</i> (Schmidtler et Bischoff, 1999) (Squamata: Lacertidae)

The adult skeletons of lacertid lizards Phoenicolacerta laevis and P. cyanisparsa are described based on cleared-and-stained specimens. In comparison with each lacertid species, there are remarkable differences in both cranial and postcranial bones. These are the shape of some cranial bones such as the premaxilla, nasal, quadrate, squamosal, jugal and dentary and the shape of the ischium and ischio-pubis opening and the number of the last presacral vertebrae with small ribs for the postcranial skeletal elements. These detailed descriptions provide as a model to compare lacertid lizards and contribute to understand squamate osteology for further studies.

Proximate and ultimate drivers of variation in bite force in the insular lizardsPodarcis melisellensisandPodarcis sicula

AbstractBite force is a key performance trait in lizards because biting is involved in many ecologically relevant tasks, including foraging, fighting and mating. Several factors have been suggested to impact bite force in lizards, such as head morphology (proximate factors), or diet, intraspecific competition and habitat characteristics (ultimate factors). However, these have been generally investigated separately and mostly at the interspecific level. Here we tested which factors drive variation in bite force at the population level and to what extent. Our study includes 20 populations of two closely related lacertid species, Podarcis melisellensis and Podarcis sicula, which inhabit islands in the Adriatic. We found that lizards with more forceful bites have relatively wider and taller heads, and consume more hard prey and plant material. Island isolation correlates with bite force, probably by driving resource availability. Bite force is only poorly explained by proxies of intraspecific competition. The linear distance from a large island and the proportion of difficult-to-reduce food items consumed are the ultimate factors that explain most of the variation in bite force. Our findings suggest that the way in which morphological variation affects bite force is species-specific, probably reflecting the different selective pressures operating on the two species.