Podarcis Hispanica Research Articles

Adult neurogenesis in the telencephalon of the lizard Podarcis liolepis.

In adult lizards, new neurons are generated from neural stem cells in the ventricular zone of the lateral ventricles. These new neurons migrate and integrate into the main telencephalic subdivisions. In this work we have studied adult neurogenesis in the lizard Podarcis liolepis (formerly Podarcis hispanica) by administering [3H]-thymidine and bromodeoxyuridine as proliferation markers and euthanizing the animals at different survival times to determine the identity of progenitor cells and to study their lineage derivatives. After short survival times, only type B cells are labeled, suggesting that they are neural stem cells. Three days after administration, some type A cells are labeled, corresponding to recently formed neuroblasts. Type A cells migrate to their final destinations, where they differentiate into mature neurons and integrate into functional circuits. Our results after long survival periods suggest that, in addition to actively dividing type B cells, there is also a type B subpopulation with low proliferative activity. We also found that new neurons incorporated into the olfactory bulb are generated both in situ, in the walls of the anterior extension of the lateral ventricle of the olfactory bulbs, but also at more caudal levels, most likely in anterior levels of the sulcus ventralis/terminalis. These cells follow a tangential migration toward the olfactory bulbs where they integrate. We hypothesized that at least part of the newly generated neurons would undergo a specialization process over time. In support of this prediction, we found two neuronal populations in the cellular layer of the medial cortex, which we named type I and II neurons. At intermediate survival times (1 month) only type II neurons were labeled with [3H]-thymidine, while at longer survival times (3, 6, or 12 months) both type I and type II neurons were labeled. This study sheds light on the ultrastructural characteristics of the ventricular zone of P. liolepis as a neurogenic niche, and adds to our knowledge of the processes whereby newly generated neurons in the adult brain migrate and integrate into their final destinations.

Identification of morphologically cryptic species with computer vision models: wall lizards (Squamata: Lacertidae: Podarcis) as a case study

Abstract Automated image classification is a thriving field of machine learning, and various successful applications dealing with biological images have recently emerged. In this work, we address the ability of these methods to identify species that are difficult to tell apart by humans due to their morphological similarity. We focus on distinguishing species of wall lizards, namely those belonging to the Podarcis hispanicus species complex, which constitutes a well-known example of cryptic morphological variation. We address two classification experiments: (1) assignment of images of the morphologically relatively distinct P. bocagei and P. lusitanicus; and (2) distinction between the overall more cryptic nine taxa that compose this complex. We used four datasets (two image perspectives and individuals of the two sexes) and three deep-learning models to address each problem. Our results suggest a high ability of the models to identify the correct species, especially when combining predictions from different perspectives and models (accuracy of 95.9% and 97.1% for females and males, respectively, in the two-class case; and of 91.2% to 93.5% for females and males, respectively, in the nine-class case). Overall, these results establish deep-learning models as an important tool for field identification and monitoring of cryptic species complexes, alleviating the burden of expert or genetic identification.

Nuclear phylogenies and genomics of a contact zone establish the species rank of Podarcis lusitanicus (Squamata, Lacertidae)

Unravelling when divergent lineages constitute distinct species can be challenging, particularly in complex scenarios combining cryptic diversity and phylogenetic discordances between different types of molecular markers. Combining a phylogenetic approach with the study of contact zones can help to overcome such difficulties. The Podarcis hispanicus species complex has proven to be prosperous in independent evolutionary units, sometimes associated with cryptic diversity. Previous studies have revealed that one of the species of this complex, P. guadarramae, comprises two deeply divergent yet morphologically indistinguishable evolutionary units, currently regarded as subspecies (P. g. guadarramae and P. g. lusitanicus). In this study we used molecular data to address the systematics of the two lineages of Podarcis guadarramae and the closely related P. bocagei. Firstly, we reconstructed the species tree of these three and two additional taxa based on 30 nuclear loci using the multispecies coalescent with and without gene flow. Secondly, we used SNPs obtained from RADseq data to analyze the population structure across the distribution limits P. g. lusitanicus and P. g. guadarramae, and for comparison, a contact zone between P. bocagei and P. g. lusitanicus. Nuclear phylogenetic relationships between these three taxa are clearly difficult to determine due to the influence of gene flow, but our results give little support to the monophyly of P. guadarramae, potentially due to a nearly simultaneous divergence between them. Genetic structure and geographic cline analysis revealed that the two lineages of P. guadarramae replace each other abruptly across the sampled region and that gene flow is geographically restricted, implying the existence of strong reproductive isolation. Podarcis bocagei and P. g. lusitanicus show a similar degree of genetic differentiation and reproductive isolation, with very low levels of admixture in syntopy. These results support that all three forms are equally differentiated and reproductively isolated. In consequence, we conclude that the two former subspecies of Podarcis guadarramae constitute valid, yet cryptic species, that should be referred to as P. lusitanicus and P. guadarramae.

Multilocus and morphological analysis of south‐eastern Iberian Wall lizards (Squamata, Podarcis)

AbstractThe phylogenetic relationships among the wall lizards of the Podarcis hispanicus complex that inhabit the south‐east (SE) of the Iberian Peninsula and other lineages of the complex remain unclear. In this study, four mitochondrial and two nuclear markers were used to study genetic relationships within this complex. The phylogenetic analyses based on mtDNA gene trees constructed with ML and BI, and a species tree using *BEAST support three divergent clades in this region: the Valencia, Galera and Albacete/Murcia lineages. These three lineages were also corroborated in species delimitation analyses based on mtDNA using bPTP, mPTP, GMYC, ABGD and BAPS. Bayesian inference species delimitation method (BPP) based on both nuclear data and a combined data set (mtDNA + nuclear) showed high posterior probabilities for these three SE lineages (≥0.94) and another Bayesian analysis (STACEY) based on combined data set recovered the same three groups in this region. Divergence time dating of the species tree provided an estimated divergence of the Galera lineage from the other SE group (Podarcis vaucheri, (Albacete/Murcia, Valencia)) at 12.48 Ma. During this period, the Betic–Rifian arc was isolated, which could have caused the isolation of the Galera form distributed to the south of the Betic Corridor. Although lizards from the Albacete/Murcia and Galera lineage are morphologically similar, they clearly represent distinct genetic lineages. The noteworthy separation of the Galera lineage enables us to conclude that this lineage must be considered as a new full species.

Getting ahead: exploitative competition by an invasive lizard

Biological invasions are a contemporary global threat because invasive species can have substantial negative economic and ecological impacts. Invasive species can outcompete native species through two main mechanisms: interference competition (direct, negative interactions like aggression) and/or exploitative competition (indirect, negative interactions resulting from species using the same, limited resources like food). The invasive Italian wall lizard (Podarcis siculus) was introduced into Lisbon, Portugal, 20 years ago, and is believed to be locally displacing the native green Iberian wall lizard (Podarcis virescens). We experimentally tested for competition between these two lizard species by establishing heterospecific (one pair of each species) and conspecific (two pairs of the same species; control) treatments in enclosures containing a high- and a low-quality refuge. Lizards were fed from food dishes every other day. We tested if species showed interference (aggressive behaviour, stealing food and shelter exclusion) or exploitative competition (tolerance between species but differences in food consumption efficiency). We found evidence for exploitative competition: the invasive species arrived first at food stations, consumed more food and gained more weight than the native species. We suggest that exploitative competition may, in part, explain the observed displacement of P. virescens from contact areas with the invasive P. siculus. Deciphering the competitive mechanisms between invasive and native species is vital for understanding the invasion process. To become successful invaders, alien species must often outcompete native species they encounter in a new location. But how can an alien species outcompete a resident with a long evolutionary history in an environment in which the resident is expected to be better adapted? We studied an invasive and native congeneric pair of sympatric lizards to understand how they interact and potentially compete in a controlled environment. The invasive Italian wall lizard and a native congener were very tolerant of each other; however, the invasive species was first to arrive at food, ate more and grew faster, suggesting exploitative competition. This contrasts with previous studies in other introduced locations where the Italian wall lizard was more aggressive towards native lizards, suggestive of interference competition. Our results help explain why the Italian wall lizard is so successful and suggests it may compete in different ways, possibly in response to local environmental conditions and which species it may be competing with, but with the same outcome: the displacement of native species.

Can behaviour explain invasion success? A comparison between sympatric invasive and native lizards

To reduce the impact of biological invasions, we need to understand the behavioural mechanisms that enable some species to be successful invaders. Testing differences in behaviour between sympatric congeneric species with different invasive potential is an opportunity to study specific behavioural traits associated with invasion success. Using the invasive Italian wall lizard, Podarcis sicula, and a noninvasive congeneric, the green Iberian wall lizard, Podarcis virescens, which live in sympatry in a location that is novel for P. sicula, we tested their exploratory behaviour, neophobia and boldness: all traits that should promote invasion success. The invasive P. sicula was more exploratory, bold and neophilic than the sympatric native P. virescens. Native lizards had highly repeatable behaviour, whereas in P. sicula boldness was the only behavioural trait that was repeatable. The behavioural traits of the native species, but not the invasive species, were correlated. A lack of correlation between behavioural traits, as well as a lack of repeatability in two of the three behavioural traits, suggests higher levels of behavioural plasticity in P. sicula, which may also explain the success of this lizard during invasions. Our experiment highlights the potential importance of behavioural traits in invasions and provides insight into why P. sicula is such a successful invader.

The Occurrence of Protozoan Parasites (Schellackia sp. Reichenow, 1919, Tritrichomonas sp. Kofoid, 1920, and Proteromonas sp. Kunstler, 1883) in Lacertid Lizards from Selected Localities in Europe

Reptiles often serve as hosts for various endo- and ectoparasites including protozoan blood and intestinal parasites. In this study, we report the occurrence of protozoans belonging to three families: Trichomonadidae, Proteromonadidae, and Lankesterellidae, in lizard blood samples. A total of 738 individuals of 4 lizard species (Lacerta agilis, Lacerta viridis, Podarcis muralis, and Zootoca vivipara) captured from 4 European countries (Hungary, Poland, Romania, and Slovakia) were examined. One blood smear obtained in 2008 from L. agilis (Odolanow, Poland) was found to be infected with trophozoites representing three genera: Karyolysus lacazei, Tritrichomonas sp., and Proteromonas sp. Moreover, Proteromonas sp. were detected by molecular methods in another individual of Lacerta agilis exigua (Romania, Vadu), which revealed 100% similarity with the isolate of Proteromonas lacertae isolated from the American Type Culture Collection (GenBank accession number U37108). Sporozoites of Schellackia sp. were detected in blood smears from 2 individuals of L. viridis from Slovakia. Molecular detection revealed the occurrence of Schellackia sp. in 2 individuals, L. viridis (Slovakia) and Lacerta agilis erythronota (Romania) and showed 99% and 90% similarity, respectively, with isolates of Schellackia-like parasites obtained from Lacerta schreiberi (GenBank acc. no. JX984675, JX984674) and Podarcis hispanica (GenBank acc. no. X984676, JQ762306, KJ18938) from Portugal and Spain. This study represents documentation of multiple infections (trophozoites of Karyolysus sp., Tritrichomonas sp., and Proteromonas sp.) detected in a sand lizard from Poland, and the first report of Schellackia in populations of a green lizards (Slovakia) and sand lizards (Romania), as well as the first evidence of Proteromonas sp. from the Romania population of sand lizards.

Experience may allow increasing accuracy of the innate chemosensory recognition of snake predators by Iberian wall lizards

Many animals can recognize chemical cues of predators and show defensive responses, but antipredatory behavior can be costly and should be modulated depending on the level of risk posed by each predatory species. Recognition ability may be innate, but it is not clear whether there might also be local adaptation to predation pressure levels or some learning component. We examined the chemosensory ability of naive and adult Iberian wall lizards, Podarcis hispanicus, to detect chemical cues of two closely related Coronella snake species in two localities within the same continuous population. Lizards in each locality are sympatric with only one of the two snake species. Our results showed an innate chemosensory discrimination of predatory snake cues, as both adult lizards and captive reared naive hatchlings, which had not had any previous experience with the snake cues, had short latencies to the first tongue-flick, increased tongue-flick responses, and active escape behavior from the scent of either of the two snake species. Moreover, adult lizards, but not naive hatchlings, showed differential responses to the two different snake species, with higher responses to the snake species that is sympatric in each locality. This strongly suggests that there is a learning component acquired through previous lifetime experiences that may increase accuracy of the discrimination of the sympatric snake. Therefore, through learning of local conditions, lizards may modulate their innate antipredatory responses to the risk level posed by each snake species.

Interpopulational Variations in Sexual Chemical Signals of Iberian Wall Lizards May Allow Maximizing Signal Efficiency under Different Climatic Conditions.

Sexual signals used in intraspecific communication are expected to evolve to maximize efficacy under a given climatic condition. Thus, chemical secretions of lizards might evolve in the evolutionary time to ensure that signals are perfectly tuned to local humidity and temperature conditions affecting their volatility and therefore their persistence and transmission through the environment. We tested experimentally whether interpopulational altitudinal differences in chemical composition of femoral gland secretions of male Iberian wall lizards (Podarcis hispanicus) have evolved to maximize efficacy of chemical signals in different environmental conditions. Chemical analyses first showed that the characteristics of chemical signals of male lizards differed between two populations inhabiting environments with different climatic conditions in spite of the fact that these two populations are closely related genetically. We also examined experimentally whether the temporal attenuation of the chemical stimuli depended on simulated climatic conditions. Thus, we used tongue-flick essays to test whether female lizards were able to detect male scent marks maintained under different conditions of temperature and humidity by chemosensory cues alone. Chemosensory tests showed that chemical signals of males had a lower efficacy (i.e. detectability and persistence) when temperature and dryness increase, but that these effects were more detrimental for signals of the highest elevation population, which occupies naturally colder and more humid environments. We suggest that the abiotic environment may cause a selective pressure on the form and expression of sexual chemical signals. Therefore, interpopulational differences in chemical profiles of femoral secretions of male P. hispanicus lizards may reflect adaptation to maximize the efficacy of the chemical signal in different climates.

Dorsal pattern polymorphism in female Iberian wall lizards: differences in morphology, dorsal coloration, immune response, and reproductive investment

Sex-specific colour polymorphisms have been extensively documented in many different taxa. When polymorphism in colour pattern is restricted to females, the condition is known as female-limited pattern polymorphism (FPP), which has been less commonly addressed in vertebrates. FPP is present in several lizard species, although most research on lizards has focused on carotenoid- and pteridine-based coloration and not on melanin-based polymorphisms. In the present study, we focus on Iberian wall lizards, Podarcis hispanicus, where two female melanin-based dorsal patterns can be clearly distinguished: striped and reticulated-blotched. We indirectly tested the hypothesis that selection acts differentially among P. hispanicus female morphs to create alternative morph-specific phenotypic optima at different levels by investigating whether morphs differ in fitness proxies. We specifically examined whether the two female dorsal pattern morphs differed in adult morphology, dorsal coloration, immune response, reproductive investment, and growth. We did not find a relationship between melanin-based coloration and hatchling growth and immune response, despite a correlation between these traits possibly being expected as a result of pleiotropy in the melanocortin system. However, our results show that female dorsal morphs in P. hispanicus differ in terms of adult morphology, dorsal coloration, and reproductive investment. Reticulated-blotched P. hispanicus females had deeper heads and longer femora, less melanin, and more brownish coloration, and also had larger and heavier hatchlings than striped females.

The importance of lizards and small mammals as reservoirs for Borrelia lusitaniae in Portugal.

Borrelia lusitaniae is a pathogen frequent in the Mediterranean area. Apart from lizards, evidence for birds and small mammals as competent reservoirs for this genospecies has been occasional. We collected questing ticks, skin biopsies and Ixodes sp. ticks feeding on lizards, birds and small mammals in a B. burgdorferi s.l. (sensu lato) enzootic area to assess their importance in the maintenance of B. lusitaniae. Borrelia lusitaniae was the most prevalent genospecies in questing ticks and was commonly found in larvae feeding on Psammodromus algirus. One biopsy infected with B. lusitaniae was collected from the tail of one Podarcis hispanica, which suggests systemic infection. Ixodes ricinus larvae feeding on Apodemus sylvaticus were infected with B. lusitaniae but with a lower prevalence. Our results reinforce the importance of lizards as reservoirs for B. lusitaniae, suggesting that P. algirus, in particular, acts as main reservoir for B. lusitaniae in Portugal.

Altitudinally divergent adult phenotypes in Iberian wall lizards are not driven by egg differences or hatchling growth rates.

The interplay between ecological conditions and life histories has been widely acknowledged in vertebrates, particularly in lizards. Environmental conditions may exert different selective pressures and produce divergent phenotypes even in geographically and genetically close populations. The Iberian wall lizard constitutes a perfect model organism as it is considered a species complex with a complicated evolutionary history. Here, we focus on two proximate populations in which we examined adult morphology and reproductive investment of wild-caught lizards along a 500-m altitudinal gradient with contrasting environmental conditions, where adults show marked morphological differences in spite of being closely related. Also, we performed a common garden experiment to examine embryonic and hatchling growth. We focused on reproductive investment per clutch, incubation time, egg size, morphology and growth rate of hatchlings. Results showed clutch size differences between populations that were independent of the larger body size of highland females. However, there were no egg morphological differences between populations, except for egg width, and this difference disappeared after controlling for female body size. Hatchling lizards from both populations did not differ in morphology. Moreover, we did not observe differences between populations or sexes in hatchling growth. Overall, we provide evidence that the differences in adult body size and clutch size are not driven by size at hatching which is not contributed to by egg size, nor are intrinsic hatchling growth rates associated with the environmental conditions experienced in our common garden experiment, suggesting that adult phenotypes are not the result of intrinsic differences between populations.

Conspicuous blue tails, dorsal pattern morphs and escape behaviour in hatchling Iberian wall lizards (Podarcis hispanicus)

Predation has profound effects on the phenotypes of animal prey and, in lizards, the relationship between coloration and antipredatory behaviour has been studied in depth. However, studies that address the relationships between dorsal patterns and tail coloration with escape behaviour in polymorphic lizards are absent in the literature. We describe dorsal morphs and measured tail coloration and escape behaviour in hatchling Iberian wall lizards, Podarcis hispanicus, a species with a previously undescribed female-restricted dorsal polymorphism (reticulated-blotched males, and either striped or reticulated-blotched females) and juvenile tails with conspicuous blue coloration, which is probably used to divert predator attacks towards the autotomizable tail. Overall we provide evidence for the existence of sexual dimorphism in tail ultraviolet reflectance between reticulated females and males, with striped females being intermediate. We identified sex/dorsal morph, body size and tail brightness as predictors of different aspects of escape behaviour and suggest the existence of two alternative escape strategies between striped and reticulated-blotched females that may be dependent on dorsal morph differences, independently of sex. Reticulated-blotched females, and also males (all reticulated-blotched), ran faster and spent less time paused than striped females, which might reflect an escape behaviour strategy based on endurance in striped females. In addition, lowland males displayed tail waving as a ‘last resort’ antipredator strategy that may be related to fatigue. We concluded that hatchling antipredatory behaviour is influenced by both dorsal pattern and tail conspicuousness. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, , –. ADDITIONAL KEYWORDS: antipredatory behaviour – intermittent locomotion – Lacertidae – polymorphism – sexual dimorphism – tail waving – ultraviolet reflectance.

Microgeographical Variations in Coloration of Male Iberian Wall Lizards May Be Related to Habitat and Climatic Conditions

Intraspecific variations in coloration may represent a compromise between selection for intraspecific communication and selection for thermoregulation and predator avoidance. Iberian wall lizards, Podarcis hispanica, exhibit substantial levels of intraspecific variation that cannot be necessarily attributed to genetic differences. We compared variations in coloration and habitat use of three phenotypically distinct populations of P. hispanica in Central Spain. Results suggested that differences in coloration may be related to habitat characteristics and climatic conditions. Thus, lizards from populations with colder temperatures were darker and larger, which may favor thermoregulation. Lizards that lived in habitats with more vegetation and darker granite rocks showed a dark brown to black dorsal coloration. In contrast, lizards from habitats with gypsum and light sandy soil without vegetation or large rocks had a brighter yellow to green dorsal coloration. These differences may increase crypsis to predators in each habitat. There were also differences in the characteristics and relative importance of sexual visual signals (i.e., ventrolateral coloration and number of lateral blue spots) and chemical signals (i.e., number of femoral pores) that might increase efficiency of communication in each environment. Natural selection for traits that allow a better thermoregulation, predator avoidance, and communication might lead to population divergence.

Comparative ecophysiology of two sympatric lizards. Laying the groundwork for mechanistic distribution models

Distribution modelling usually makes inferences correlating species presence and environmental variables but does not take biotic relations into account. Alternative approaches based on a mechanistic understanding of bio- logical processes are now being applied. Regarding lacertid lizards, physiological traits such as preferred body temper - ature (Tp) are well known to correlate with several physiological optima. Much less is known about their water ecol- ogy although body temperature and evaporative water loss (Wl) may trade-off. Two saxicolous lacertids, Algyroides marchi and Podarcis hispanica ss are sympatric in the Subbetic Mountains (SE Spain) were they can be found in synto- py. Previous distribution modelling indicates the first species is associated with mountains, low temperatures; high precipitation and forest cover whereas the second one is more generalistic. Here, we perform two ecophysiological tests with both species: a Tp experiment in thermal gradient and a Wl experiment in sealed chambers. Although both species attained similar body temperatures, A. marchi lost more water and more uniformly in time than P. hispanica ss that displayed an apparent response to dehydration. These results suggest that water loss rather temperature is crucial to explain the distribution patterns of A. marchi in relation to P. hispanica ss, the former risking dehydration in dry areas no matter what temperature is. Ecophysiological traits represent a promising tool to build future mechanistic models for (lacertid) lizards. Additionally, the implications for their biogeography and conservation are discussed.

Differences in Thermal Biology Between Two Morphologically Distinct Populations of Iberian Wall Lizards Inhabiting Different Environments

Populations should adapt to the climate at their respective localities. Here, we examined differences in thermal biology between two populations of Podarcis hispanica lizards from areas with different climates. Lizards from the cold, northern mountains attained lower field body temperatures than lizards form the warm, southern plains. However, the larger body size and darker coloration of northern lizards resulted in slower cooling rates, which may increase efficiency of thermoregulation. Northern populations selected higher temperatures in a thermal gradient, possibly as an adaptation to heat up before conditions changed, as their mountain environment is unpredictable. Finally, lizards from both populations had similar temperature-dependent locomotor performance curves, although southern lizards were relatively faster considering their smaller body size. We suggest that environmental differences may lead to differences in morphology and locally adapted thermal biology in lizards that might allow maximizing thermoregulation in each local climatic conditions.

Female mate choice based on pheromone content may inhibit reproductive isolation between distinct populations of Iberian wall lizards

Abstract The Iberian wall lizard Podarcis hispanica forms part of a species complex with several morphologically and genetically distinct types and populations, which may or may not be reproductively isolated. We analyzed whether female mate choice based on males’ chemical signals may contribute to a current pre-mating reproductive isolation between two distinct populations of P. hispanica from central Spain. We experimentally examined whether females choose to establish territories on areas scent-marked by males of their own population, versus areas marked by males of the other population. Results showed that females did not prefer scent-marks of males from their own population. In contrast, females seemed to attend mostly to among-individual variation in males’ pheromones that did not differ between populations. Finally, to test for strong premating reproductive isolation, we staged intersexual encounters between males and females. The population of origin of males and females did not affect the probability nor the duration of copulations. We suggest that the different environmental conditions in each population might be selecting for different morphologies and different chemical signals of males that maximize efficiency of communication in each environment. However, females in both populations based mate choice on a similar condition-dependent signal of males. Thus, male signals and female mate choice criteria could be precluding premating reproductive isolation between these phenotypically “distinct” populations.

Mechanisms of Speciation

Mechanisms of Speciation

Differences in Chemical Sexual Signals May Promote Reproductive Isolation and Cryptic Speciation between Iberian Wall Lizard Populations.

Interpopulational variation in sexual signals may lead to premating reproductive isolation and speciation. Genetic and morphological studies suggest that the Iberian wall lizard, Podarcis hispanica, forms part of a “species complex” with several cryptic species. We explored the role of chemical sexual signals in interpopulational recognition between five distinct populations of Iberian wall lizards in Central Spain. Results showed that these populations differed in morphology and in composition and proportion of chemical compounds in femoral gland secretions of males. Tongue-flick experiments indicated that male and female lizards discriminated and were more interested in scents of lizards from their own area (i.e., Northern versus Southern populations), but did not discriminate between all populations. Moreover, only males from the populations that are geographically located more far away preferred scent of females from their own population. These data suggest that, at least between some populations, there may be reproductive isolation mediated by chemical signals and cryptic speciation.

Lateralization in refuge selection in Podarcis hispanica at different hierarchical levels

The traditional explanation of brain lateralization is that it avoids costly duplication of neural circuitry with the same function as well as decreasing the interference between different functions. This advantage could have important ecological implications in terms of predator–prey interactions. If species are lateralized in escape behavior at an individual level, any predator is facing individually asymmetric prey. On the other hand, if species are lateralized at a higher hierarchical level, such as at the population or species level, the predator can learn from experience arising from earlier encounters. In the present study, we investigate patterns of lateralization in 5 lizard populations of the Podarcis hispanica species complex, with the aim of analyzing the occurrence of lateralization at different hierarchical levels. Our results show that refuge selection during escape behavior is not universal in the P. hispanica species complex at different hierarchical levels, some individuals and populations are lateralized, with a consistent bias toward the refuge on the right. However, 2 populations showed no refuge preference, with lack of lateralization mainly arising due to the dominance of individuals with no preference rather than from a mix of right- and left-biased individuals. When considered at the P. hispanica species complex level, a pattern for right-refuge preference was