Common Wall Lizard Podarcis Muralis Research Articles

The common wall lizard Podarcis muralis (Reptilia: Lacertidae) shows diverse food preferences and intraspecific difference: a study case from Bulgaria

The common wall lizard Podarcis muralis (Reptilia: Lacertidae) shows diverse food preferences and intraspecific difference: a study case from Bulgaria

Molecular phylogeny of the common wall lizard Podarcis muralis (Squamata: Lacertideae) in the southern Balkans

Abstract The lacertid wall lizards of the genus Podarcis (Wagler, 1830) originate from Western Europe and are divided into 24-25 species (Speybroeck et al., 2020). Despite the abundance of phylogenetic studies referring to the genus, the relationships among certain species, as well as the taxonomic status of some genealogical lineages, remain unclear due to great genetic diversity. The common wall lizard Podarcis muralis has a relatively wide distribution and despite the existence of various molecular studies focused on this species, its Greek populations had never been thoroughly sampled until now. To fill in this geographical gap, we sampled the species’ Greek distribution and constructed phylogenies that uncovered the presence of at least five monophyletic lineages that correspond to different geographic regions. Furthermore, species delimitation analyses assigned all lineages to a single species diversifying during the early Pleistocene (c. 1.93 mya). The strong association of the genetic lineages with specific geographical regions coupled with the Pleistocene diversification of the group imply the presence of multiple refugia within Greece and, by extension, the Balkan peninsula, supporting a refugia-within-refugia scenario. Finally, in an effort to clarify the position of these new samples within the larger phylogeny of P. muralis, a larger phylogeny was constructed which indicated that the Greek populations cluster with the central European, Italian and Turkish populations of the species.

Common wall lizards Podarcis muralis at a new site in England registered by a citizen science reporting tool

Common wall lizards Podarcis muralis at a new site in England registered by a citizen science reporting tool

Precise paternal ancestry of hybrid unisexual ZW lizards (genus Darevskia: Lacertidae: Squamata) revealed by Z-linked genomic markers

Abstract We genotyped multiple populations of all seven parthenogenetic species of rock lizards, genus Darevskia, as well as their putative sexual parental populations, using double digest RAD-sequencing genomic markers. Taking advantage of the conserved homology of the ZW/ZZ sex chromosomes among lacertid lizards, we aligned our short sequence reads to a reference Z chromosome assembly of the common wall lizard Podarcis muralis. This provided unique insight into the origin of all-female hybrid populations, which inherited their single Z chromosome exclusively from a paternal ancestor. The mapped Z-linked loci were used to construct a robust time-calibrated phylogeny. In each parent–offspring species pair, the geographically nearest population of the paternal species was identified as the most likely ancestor of the respective parthenogen, mirroring the trend observed previously on the maternal side in mitochondrial DNA. The estimated splits between the sampled paternal sexual ancestors and their daughter species occurred much earlier than suggested previously and during two narrow time periods: (1) the parthenogenetic Darevskia armeniaca, D. dahli, D. uzzelli and D. rostombekowi dated back to ~0.5 or ~0.9 Mya, depending on the calibration point used, while (2) D. bendimahiensis, D. sapphirina and D. unisexualis appear to have diverged ~1 or ~2 Mya.

Population genetic differentiation and genomic signatures of adaptation to climate in an abundant lizard

Species distributed across climatic gradients will typically experience spatial variation in selection, but gene flow can prevent such selection from causing population genetic differentiation and local adaptation. Here, we studied genomic variation of 415 individuals across 34 populations of the common wall lizard (Podarcis muralis) in central Italy. This species is highly abundant throughout this region and populations belong to a single genetic lineage, yet there is extensive phenotypic variation across climatic regimes. We used redundancy analysis to, first, quantify the effect of climate and geography on population genomic variation in this region and, second, to test if climate consistently sorts specific alleles across the landscape. Climate explained 5% of the population genomic variation across the landscape, about half of which was collinear with geography. Linear models and redundancy analyses identified loci that were significantly differentiated across climatic regimes. These loci were distributed across the genome and physically associated with genes putatively involved in thermal tolerance, regulation of temperature-dependent metabolism and reproductive activity, and body colouration. Together, these findings suggest that climate can exercise sufficient selection in lizards to promote genetic differentiation across the landscape in spite of high gene flow.

Predation on Common Wall Lizards: Survival Probabilities of Melanic Individuals

For estimation of predation plasticine models of prey animals are often used, because the soft material preserves imprints left by predators. We assumed that melanic common wall lizards (Podarcis muralis) disappear by selective predation faster than cryptic individuals and habitat features have important role in this process. We studied the survival probabilities of cryptic and melanic colored plasticine common wall lizard models in habitats with different background coloration on selected places near the city of Pécs (south Hungary), where melanic common wall lizards had been observed earlier. Contrary to our expectations the daily survival rates of melanic plasticine common wall lizards were somewhat higher in all three locations (sandstone quarry, stone wall, coal pit) than those of the cryptic ones, but these differences were not significant. Predators were mostly mammals, which left more marks on plasticine models than birds, but we could not show a preference of the body parts of prey. We concluded that rare occurrence of melanic common wall lizards in habitats near the city of Pécs is not due to predation pressure.

Aggressive interactions between a sand lizard Lacerta agilis and a common wall lizard Podarcis muralis in England

Aggressive interactions between a sand lizard Lacerta agilis and a common wall lizard Podarcis muralis in England

Subjective resource value affects aggressive behavior independently of resource-holding-potential and color morphs in male common wall lizard

Game theory models predict the outcome of a dyadic contest to depend on opponents’ asymmetries in three main traits: resource-holding potential (RHP), resource value (RV) and aggressiveness. Using male common wall lizards Podarcis muralis, a polymorphic species showing three discrete morphs (white, yellow, and red), we investigated how the aggressive behavior varies according to a change in subjective RV and color morphs, while controlling for the asymmetry in RHP (using mirrors). By comparing the aggression of the same individual towards its mirror image in two different arenas (familiar = high subjective RV; novel = low subjective RV), we showed that lizard aggressive behavior was more intense and prolonged in the familiar arena than in the new one, thus supporting the occurrence of a direct relationship between motivation and aggression in this species. We also found the overall aggressiveness to differ from individual to individual, supporting the general hypothesis that aggressiveness is a trait associated with personality. By contrast, no effect of morphs was detected, ruling out the occurrence of morph specific variation in the aggressiveness. Our results highlight that an individual’s motivation and personality might be as important as RHP and RV in the resolution of animal contests.

No evidence for differential sociosexual behavior and space use in the color morphs of the European common wall lizard (Podarcis muralis).

Explaining the evolutionary origin and maintenance of color polymorphisms is a major challenge in evolutionary biology. Such polymorphisms are commonly thought to reflect the existence of alternative behavioral or life‐history strategies under negative frequency‐dependent selection. The European common wall lizard Podarcis muralis exhibits a striking ventral color polymorphism that has been intensely studied and is often assumed to reflect alternative reproductive strategies, similar to the iconic “rock–paper–scissors” system described in the North American lizard Uta stansburiana. However, available studies so far have ignored central aspects in the behavioral ecology of this species that are crucial to assess the existence of alternative reproductive strategies. Here, we try to fill this gap by studying the social behavior, space use, and reproductive performance of lizards showing different color morphs, both in a free‐ranging population from the eastern Pyrenees and in ten experimental mesocosm enclosures. In the natural population, we found no differences between morphs in site fidelity, space use, or male–female spatial overlap. Likewise, color morph was irrelevant to sociosexual behavior, space use, and reproductive success within experimental enclosures. Our results contradict the commonly held hypothesis that P. muralis morphs reflect alternative behavioral strategies, and suggest that we should instead turn our attention to alternative functional explanations.

Vertical Transmission of a Nematode from Female Lizards to the Brains of Their Offspring.

Parasites have evolved a diversity of lifestyles that exploit the biology of their hosts. Some nematodes that parasitize mammals pass via the placenta or milk from one host to another. Similar cases of vertical transmission have never been reported in avian and nonavian reptiles, suggesting that egg laying may constrain the means of parasite transmission. However, here we report the first incidence of transovarial transmission of a previously undescribed nematode in an egg-laying amniote, the common wall lizard (Podarcis muralis). Nematodes enter the developing brain from the female ovary early in embryonic development. Infected lizard embryos develop normally and hatch with nematodes residing in their braincase. We present a morphological and molecular phylogenetic characterization of the nematode and suggest that particular features of lizard biology that are absent from birds and turtles facilitated the evolutionary origin of this novel life history.

Urbanization and the common wall lizard (Podarcis muralis) in the Pannonian basin, Serbia: nowhere safe?

AbstractNumerous studies of urban environment impact on wildlife imply urbanization can have both negative and positive effects. Phenotypic variation of pileus in the common wall lizard (Podarcis muralis) was analysed to determine whether urbanization levels can be associated with developmental instability induced by environmental stress. Pileus developmental pathways and instability in natural, suburban and urban populations were quantified by patterns of size and shape, fluctuating asymmetry (FA), modular organization and integration, allometric trajectories and frequency of phenodeviants. Our results show high asymmetry and modular structure of pileus with the high frequency of phenodeviants for natural, suburban and urban populations indicating elevated developmental instability in all three habitat types. However, some peculiarities were observed comparing habitats – the lowest level of FA and integration in urban populations and unexpectedly high level of FA and frequency of phenodeviants in the natural population. In addition, significant correlations between symmetric and asymmetric shape patterns, and presence of modular organization for all three habitat types suggest that genetic/environmental and developmental parcellation are somewhat aligned. Our results indicate that pileus morphology varies in a complex manner and future studies that link physiological, behavioural and morphological parameters to demographic parameters and fitness are necessary to fully understand how environmental stress affects developmental instability.

The relative importance of body size and UV coloration in influencing male-male competition in a lacertid lizard

Communication via color signals is common in natural systems. Ultraviolet (UV)-blue patches located on the outer-ventral scales of some lacertid lizards are thought to be involved in male-male competition. However, the mechanisms that maintain their honesty remain unknown. Here, we use the common wall lizard Podarcis muralis to test whether the lateral UV-blue spots are conventional signals, the honesty of which is guaranteed by receiver-dependent costs, and discuss their potential role as an amplifier of body size. We first described the morphology and reflectance properties of lateral UV-blue spots in common wall lizards and investigated how they influence male-male competition. Spot size and number, UV chroma, and conspicuousness (calculated using vision models) were significantly greater in adult males relative to adult females and adult males relative to juveniles. Total spot area (and not spot number) of adult males was positively correlated with body size. We conducted staged competition encounters between focal males and smaller or larger rivals with control or manipulated spots. Spots were enlarged in small rivals and reduced in large rivals to disrupt the phenotypic correlation between spot area and body size. Aggressiveness and dominance were positively influenced by body size in control encounters. Spot manipulations resulted in greater submission and less aggressiveness in focal males. These results contradict the predictions associated with conventional signals and amplifiers, but suggest that spots contributed to opponent evaluation during short-distance encounters between competing males. Many animals use color to communicate. During intraspecific resource competition, some species use color signals as an assessment tool to determine if they should engage in or avoid conflicts. Studies have found that in non-mammalian vertebrates, UV coloration can be a good indicator of fighting ability or aggressiveness. We tested whether and how the UV-blue spots of common wall lizards play a role in male-male competition by studying the properties of their spots, and then used that information to design and conduct competition experiments between males involving spot manipulation. Both body size and spot manipulation influenced aggression and submission during encounters. In particular, results suggest that spot manipulation disrupted mutual assessment and thus that spots play a role in competition signaling in male common wall lizards.

Asymmetry in the common wall lizard Podarcis muralis under different levels of urbanization: The effect of trait and FA index selection

The use of fluctuating asymmetry (FA) as a measure of developmental instability and its relationship to stress and fitness is highly controversial. We examined whether the selection of different FA indices and traits influences the results of FA analysis. We chose four meristic traits and three FA indices (two single-trait and two multiple-trait indices) to assess FA levels in the common wall lizard (Podarcis muralis) from three different habitat types (urban, suburban and natural). Urbanization has already been linked to developmental instability in P. muralis. We therefore expected to detect different FA levels among the habitats. However, we also wanted to see whether we obtained the same patterns using different indices and traits. Our results showed that different traits can yield different FA patterns between habitats. The only statistically significant difference between habitats was detected for the FA2 index in femoral pores. The highest level of FA was detected in the urban population, while the lowest level was in the natural population. It is clear that caution must be exerted when deciding on which traits and indices are to be used for FA analysis. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI173043, Grant no. III43001]

Predation of common wall lizards: experiences from a study using scentless plasticine lizards

The potential influence of predators on lacertid lizards has been studied by using models made of plasticine which shows the attack marks of predators and as such allows their identification and estimation of predation pressure. The general aim was to study predation on plasticine models of lizards and to improve methods, since the results depend on the number of plasticine models used, their spatial pattern and the duration of experiments. We estimated the density of the common wall lizard Podarcis muralis population on stone walls of a vineyard in the city of Pecs (Hungary) in August 2015 in order to imitate the real density in our experiment with plasticine models. The density of common wall lizards was 8.2 ind. /100 m 2 and accordingly we placed 25 scentless plasticine lizards on the stone walls on the first transect with 10 m distance between them, which imitates the real pattern. In the second transect 25 lizard models were placed more sparsely, the distance between them being 20 m. During four weeks the predation rate was 24% in densely spaced plasticine lizards and 40% in sparsely spaced plasticine lizards, but the difference was not significant. The daily survival rate of densely spaced lizards was 0.99 (=99.1%) and that of sparsely spaced lizard models was 0.98 (=98.25%), but this difference was not significant either. On the basis of marks left on plasticine lizards, mammal predators (e.g. beech marten) dominated, while the impact of bird predators was smaller than expected. Predators attacked the head of plasticine lizards more frequently than their trunk, tail or limbs, but a significant preference of body parts was not detected. From our experience it is important to study the distribution and density of real animals, to imitate their real pattern, instead of an arbitrarily designed experiment with models. The typical scent of plasticine also could influence the results, which can be avoided by using scentless plasticine models coated with liquid rubber. We suggest the calculation of daily survival rates in order to produce results that allow the comparison of different studies.

Morph-specific assortative mating in common wall lizard females.

Color polymorphism often is associated with alternative reproductive strategies and may reflect different adaptive optima that coexist within populations. The equilibrium among morph frequencies is maintained by the occurrence of opposite selective pressures (disruptive vs. stabilizing), which promote polymorphism while preserving gene flow. Sexual selection may contribute on both sides, particularly when morphs do not mate randomly. Reptiles offer a good model, notably lizards. Nevertheless, previous studies on mate choice in polymorphic lizards have generated contrasting results, with some studies suggesting that female morphs might tune their preference depending on environmental/social conditions such as crowding. We experimentally manipulated the number of individuals a female common wall lizard Podarcis muralis perceives around her, to test if females of different morphs (white or yellow) tune their choice for white and yellow males in order to maximize the probability that hatchlings follow the strategy best adapted to the population density. Results showed that crowding experienced by females did not affect mate choice, arguing against a flexible choice strategy by females. However, white females significantly associated with white males, whereas yellow females did not significantly associate with yellow males. Thus, sexual selection could contribute to the maintenance of color polymorphism in this species by a mix of assortative and non-assortative mating strategies, which could maintain the equilibrium between gene divergence and gene flow among morphs.

Female reproductive investment in response to male phenotype in wall lizards and its implications for introgression

The likelihood that females will breed or how much they invest in reproduction can depend on the characters of their male partners. Such differential allocation may enhance or limit gene flow between hybridizing lineages, in particular when the lineages have diverged in sexually selected characters. Populations of the common wall lizard (Podarcis muralis) in some regions of Italy exhibit striking exaggeration of coloration, morphology and behaviour compared to populations in France. The two forms hybridize in north-western Italy. Gene flow is directional and in concordance with the prediction that the exaggerated sexual characters of lizards of Italian origin give them a mating advantage. To evaluate if differential allocation contributes to asymmetric introgression, we tested experimentally if female reproductive investment is affected by male origin and male secondary sexual characters. Despite the large genetic and phenotypic divergence between males of Italian and French origin, females did not invest more when paired with males of the same origin, nor when paired with males with highly expressed sexual characters. Combined, these results suggest that female responses to male phenotypes in wall lizards are unimportant for explaining the directional pattern of gene flow in regions of secondary contact.

Inter- and intra-population variability of the protein content of femoral gland secretions from a lacertid lizard.

Femoral glands of male lizards produce waxy secretions that are involved in inter- and intraspecific chemical communication. The main components of these secretions are proteins and lipids, the latter having been extensively studied and already associated to male quality. On the opposite, the composition and role of proteins are nearly unknown, the only available information coming from few studies on iguanids. These studies got the conclusion that proteins might have a communicative function, notably they could signal individual identity. A generalization of these findings requires the extension of protein analysis to other lizard families, and the primary detection of some patterns of individual variability. Using the common wall lizard Podarcis muralis as a model species, the protein fraction of the femoral pore secretions was investigated to provide the first characterization of this component in a lacertid lizard and to explore its source of variability, as a first step to support the hypothesized communicative role. Samples of proteins from femoral secretions were collected from 6 Italian populations and subjected to 1-dimensional electrophoresis. The binary vector of the band presence/absence was used to define the individual profiles. Protein fraction is found to have a structured pattern, with both an individual and a population component. Although the former supports the potential communicative role of proteins, the latter offers a double interpretation, phylogenetic or environmental, even though the phylogenetic effect seems more likely given the climatic resemblance of the considered sites. Further studies are necessary to shed light on both these issues.

Genetic and phenotypic component in head shape of common wall lizard Podarcis muralis

Head shape in lizards correlates with a wide range of environmental pressures, supporting the hypothesis that patterns of phenotypic change represent adaptive responses to selective processes. However, natural selection promotes evolutionary adaptation only if the trait under selection has enough heritable variation. In this study we used geometric morphometrics and quantitative genetics to assess the heritability patterns of the head shape and size of common wall lizards (Podarcis muralis). Genetic and phenotypic components were estimated using animal models, which showed that more than half of the variation in head morphology is inheritable. Furthermore, at least five independent patterns of genetically determined phenotypic change were detected. These outcomes confirm that morphological differentiation in common wall lizards may reliably be regarded as the result of adaptive processes driven by natural selection.

Réponses des populations de reptiles à l’éradication du Rat noir (Rattus rattus) sur l’île de Bagaud (parc national de Port-Cros, Var, France)

Responses of reptile populations to the eradication of the Roof Rat (Rattus rattus) on Bagaud Island (Port-Cros National Park, Var, France). — An eradication of two invasive taxa, the Roof Rat (Rattus rattus) and Ice plants (Carpobrotus spp.), was undertaken in 2011 and 2012 on the protected nature reserve of Bagaud island, located in Port-Cros national Park (south-eastern France). R. rattus eradication was successful while Carpobrotus spp. eradication is still in progress. To assess the effects of R. rattus eradication on island reptile populations (Montpellier Snake Malpolon monspessulanus, European Leaf-toed Gecko Euleptes europaea, Common Wall Lizard Podarcis muralis), a pre-eradication monitoring was conducted in 2010 and 2011, and a post-eradication monitoring in 2013 and 2014. Census was performed with three semi-quantitative methods : (1) three transects of 80 m long and 2 m wide ; (2) two quadrats 1225 m² ; (3) five rocky microsites, habitats for E. europaea. Very few individuals of M. monspessulanus were observed. Significant results were obtained only for E. europaea : after eradication, the number of observed juveniles increased and all observed individuals, independently of their age groups, were more outside shelters than inside. These results can be explained by the loss of avoidance behaviour that E. europaea displayed when in presence of R. rattus, and by lower predation pressure, given that both species are nocturnal. The elapsed time since eradication of R. rattus is quite short and some species have not necessarily visibly responded demographically. Additional monitoring in the coming years will provide further insights.

Observations of the common wall lizard Podarcis muralis maculiventris (Werner, 1891) outside its natural range in Slovenia

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