Lacerta Agilis Research Articles

Correction to: Breaking through the eggshell: embryonic development of the premaxillary dentition in Lacerta agilis (Squamata: Unidentata) with special emphasis on the egg tooth

Correction to: Breaking through the eggshell: embryonic development of the premaxillary dentition in <i>Lacerta agilis</i> (Squamata: Unidentata) with special emphasis on the egg tooth

Breaking through the eggshell: embryonic development of the premaxillary dentition in Lacerta agilis (Squamata: Unidentata) with special emphasis on the egg tooth

Abstract The egg tooth of squamates is a true tooth that allows them to break, tear, or cut the eggshell during hatching. In this clade there are some uncertainties concerning the egg tooth implantation geometry, the number of germs, and their fates during embryonic development. Here, we used X-ray microtomography and light microscopy, focusing on the egg tooth and remaining premaxillary teeth of the sand lizard (Lacerta agilis, Squamata: Unidentata). The developing egg tooth of this species passes through all the classic stages of tooth development. We did not find any evidence that the large size of the egg tooth is related to the merging of two egg tooth germs, which has recently been suggested to occur in snakes. Instead, this feature can be attributed to the delayed formation of the neighbouring regular premaxillary teeth. This might provide more resources to the developing egg tooth. At the last developmental stage, the egg tooth is a large, midline structure, bent forward as in most oviparous Unidentata. It is characterized by pleurodont implantation, and its base is attached to the pleura and a peculiar ridge of the alveolar bone. The attachment tissue contains periodontal ligament-like tissue, acellular cementum-like tissue, and alveolar bone.

Bacterial pathogens in Ixodes ricinus collected from lizards Lacerta agilis and Zootoca vivipara in urban areas of Wrocław, SW Poland– preliminary study

The aim of this study was to determine the level of infection of Ixodes ricinus ticks with pathogens (Borrelia spp., Rickettsia spp., and Anaplasma spp.) collected from Lacerta agilis and Zootoca vivipara lizards in the urban areas of Wrocław (SW Poland). The study was carried out in July-August 2020. Lizards were caught by a noose attached to a pole or by bare hands, identified by species, and examined for the presence of ticks. Each lizard was then released at the site of capture. Ticks were removed with tweezers, identified by species using keys, and molecular tests were performed for the presence of pathogens. From 28 lizards (17 specimens of Z. vivipara and 11 specimens of L. agilis) a total of 445 ticks, including 321 larvae and 124 nymphs, identified as I. ricinus were collected. A larger number of ticks were obtained from L. agilis compared to Z. vivipara. Molecular tests for the presence of pathogens were performed on 445 specimens of I. ricinus. The nested PCR method for the fla gene allowed the detection of Borrelia spp. in 9.4% of ticks, and it was higher in ticks from L. agilis (12.0%) than from Z. vivipara (1.0%). The RFLP method showed the presence of three species, including two belonging to the B. burgdorferi s.l. complex (B. lusitaniae and B. afzelii), and B. miyamotoi. The overall level of infection of Rickettsia spp. was 19.3%, including 27.2% in ticks collected from Z. vivipara and 17.0% from L. agilis. Sequencing of randomly selected samples confirmed the presence of R. helvetica. DNA of Anaplasma spp. was detected only in one pool of larvae collected from L. agilis, and sample sequencing confirmed the presence of (A) phagocytophilum. The research results indicate the important role of lizards as hosts of ticks and their role in maintaining pathogens in the environment including urban agglomeration as evidenced by the first recorded presence of (B) miyamotoi and (A) phagocytophilum in I. ricinus ticks collected from L. agilis. However, confirmation of the role of sand lizards in maintaining (B) miyamotoi and A. phagocytophilum requires more studies and sampling of lizard tissue.

ВПЛИВ ПОГОДНИХ УМОВ НА ЧИСЕЛЬНІСТЬ АМФІБІЙ ТА РЕПТИЛІЙ В УМОВАХ ПРИРОДНОГО ЗАПОВІДНИКА «МЕДОБОРИ» ЗА ПЕРІОД 2016–2020 РОКІВ

Based on the results of long-term observations, the influence of weather conditions on the dynamics of the number and biodiversity of amphibians and reptiles over five years in the "Medobory" nature reserve was analyzed. The number, reproduction, metamorphosis stages, and distribution of amphibians and reptiles depend significantly on climatic conditions. Low temperatures in spring inhibit spawning and larval development. During critical periods, a low amount of precipitation (e.g., 15.7 mm in May 2016, 9.1 mm in April 2018, and 12.1 mm in April 2019, compared to the norm of 45 mm) also negatively affects amphibian populations. This factor led to the disappearance of Triturus cristatus Laur., Lissotriton vulgaris L. (an outbreak was noted in 2014), and Bufo viridis Laur. from the reserve (last observed at MG-1 in 2013), as well as the less common Hyla orientalis Bedriaga. Amphibians and reptiles were recorded during the active period along two regular herpetological routes, MG-1 and MG-2, and observations were made during field research, covering all areas suitable for the reproduction and habitat of amphibians. Eleven species of amphibians have been confirmed in the reserve, belonging to six families: Salamandridae, Bombinatoridae, Pelobatidae, Bufonidae, Hylidae, and Ranidae. Among these amphibians, five species are listed in Appendix II of the Berne Convention, and one species (T. cristatus Laur.) is included in the Red Book of Ukraine. The most common amphibian species are Rana temporaria L., Rana arvalis Nilsson, and Bufo bufo L. Frogs such as Pelophylax lessonae Camerano and Pelophylax ridibundus Pallas occasionally occur within the reserve, as they require an aquatic environment even after reproduction. There are seven species of reptiles in the reserve and one in the immediate vicinity, out of the ten recorded in the Ternopil region. These reptiles occupy the most suitable habitats for their survival. The species represent five families: Emydidae (freshwater turtles), Anguidae (spindly lizards), Lacertidae (true lizards), Colubridae (snakes), and Viperidae (vipers). Common species include Lacerta agilis Andrz., Natrix natrix L., and Anguis fragilis L. Six species of reptiles are included in Appendix II of the Berne Convention, and the common copperhead (Coronella austriaca Laur.) is included in the Red Book of Ukraine.

Sex and early-life conditions shape telomere dynamics in an ectotherm.

Telomeres, the repetitive DNA regions that protect the ends of chromosomes, and their shortening have been linked to key life history trade-offs among growth, reproduction and lifespan. In contrast to most endotherms, many ectotherms can compensate for telomere shortening throughout life by upregulation of telomerase in somatic tissues. However, during development, marked by rapid growth and an increased sensitivity to extrinsic factors, the upregulation of telomerase may be overwhelmed, resulting in long-term impacts on telomere dynamics. In ectotherms, one extrinsic factor that may play a particularly important role in development is temperature. Here, we investigated the influence of developmental temperature and sex on early-life telomere dynamics in an oviparous ectotherm, Lacerta agilis. While there was no effect of developmental temperature on telomere length at hatching, there were subsequent effects on telomere maintenance capacity, with individuals incubated at warm temperatures exhibiting less telomere maintenance compared with cool-incubated individuals. Telomere dynamics were also sexually dimorphic, with females having longer telomeres and greater telomere maintenance compared with males. We suggest that selection drives this sexual dimorphism in telomere maintenance, in which females maximise their lifetime reproductive success by investing in traits promoting longevity such as maintenance, while males invest in short-term reproductive gains through a polygynous mating behaviour. These early-life effects, therefore, have the potential to mediate life-long changes to life histories.

Distribution of non-native terrestrial and freshwater amphibians and reptiles in Scotland

Surveillance of non-native species is important for biosecurity and ecological reasons. This paper presents a baseline of the distribution of non-native terrestrial and freshwater amphibian and reptile species in Scotland. Multiple datasets were used to confirm which non-native terrestrial and freshwater species of amphibians and reptiles are currently present in Scotland, and map their known distribution. Citizen Science records were found to be extremely useful when photographs were included. Four non-native terrestrial and freshwater amphibian and reptile species were found to be present in Scotland, including Alpine newt (Ichthyosaura alpestris), sand lizard (Lacerta agilis), Chinese pond turtle (Mauremys reevesii), and common slider (Trachemys scripta).

New data regarding the distribution and status of the herpetofauna from urban and peri-urban habitats in the city of Pite&amp;#537;ti, Arge&amp;#537; county (Romania)

Identifying urban and peri-urban areas inhabited by species of reptiles and amphibians represents the first step in understanding how herpetofauna can adapt to anthropogenic factors. This is particularly true for regions where sampling biases have left significant gaps in our knowledge of fauna distribution, such as Romania. The aim of the study is to show my preliminary observations on the herpetofauna and its use of habitats in the urban and peri-urban environments from the city of Pite&amp;#537;ti, Arge&amp;#537; County, located in southern Romania. I identified nine species of amphibians (Salamandra salamandra, Lissotriton vulgaris, Triturus cristatus, Bombina variegata, Bufo bufo, Bufotes viridis, Hyla orientalis, Pelophylax ridibundus and Rana dalmatina) and nine species of reptiles (Emys orbicularis, Trachemys scripta, Lacerta agilis, Lacerta viridis, Podarcis muralis, Anguis colchica, Coronella austriaca, Natrix natrix and Natrix tessellata). The most abundent species in urban environments were Podarcis muralis and Bufotes viridis, with other species naturally present in the same habitats being Lacerta viridis, Hyla orientalis and Bufo bufo. In an artificial urban pond there were present Emys orbicularis and the invasive species Trachemys scripta (together with other exotic turtles belonging to other genera) as a result of translocation and releases. When taking into account the peri-urban areas as well, the most abundant species in the study area were Bombina variegata, Rana dalmatina and Bufotes viridis, the first two being limited to the woodland area. The most widespread species were Hyla orientalis, Bufotes viridis, Lacerta viridis, Podarcis muralis and Natrix natrix. These widespread species were present throughout all the study area. I have also recorded some species of reptiles with very few observations in the Arge&amp;#537; County: Natrix tessellata and Trachemys scripta. Finally, I identified anthropogenic factors that negatively impact the herpetofauna, such as habitat loss, direct persecution, road mortality, invasive species and poaching.

Identifying Priority Areas for Conservation of An Endangered Sand Lizard Using Landscape-Based Habitat Suitability Models

Identifying Priority Areas for Conservation of An Endangered Sand Lizard Using Landscape-Based Habitat Suitability Models

PRELIMINARY OBSERVATIONS REGARDING THE HERPETOLOGICAL FAUNA FROM CORCOVA (MEHEDINȚI COUNTY)

The paper presents preliminary data on amphibian and reptile fauna from Corcova (Mehedinți county). The commune, with an area of 75.32 km2, is located in the south-west of Romania (north-east of the county), on the right bank of the Motru River. Hills prevail in terms of landforms. The study aimed to update the herpetological database with new information resulting from research conducted between March and October 2022. The preliminary list includes: 10 species of amphibians (Urodela - 3 species: Salamandra salamandra, Triturus cristatus, Lissotriton vulgaris and Anura - 7 species: Bombina bombina, Hyla orientalis, Pelobates fuscus, Bufotes viridis, Rana dalmatina, Pelophylax kl. esculentus, P. ridibundus) and 11 species of reptiles (2 species of turtles: Testudo hermanni, Emys orbicularis; 4 species of lizards: Lacerta agilis, L. viridis, Podarcis tauricus, Anguis fragilis; 5 snake species: Dolichophis caspius, Coronella austriaca, Zamenis longissimus, Natrix natrix, N. tessellata). The variety of habitats, the temperate-continental climate with sub-Mediterranean influences, the trophic resource have influenced the diversity of herpetofauna in the area. The highlighted species of amphibians and reptiles are listed on different national protectionist lists (ordinances, laws, etc.). Species that are subject to special habitat conservation measures have drawn our attention: Testudo hermanni, Emys orbicularis, Triturus cristatus, Bombina bombina, Pelobates fuscus (Annex 3 to OUG 57/2007).

Management impacts on three reptile species (Vipera ursinii, Lacerta agilis, Lacerta viridis) in sandy grasslands in Hungary: Mowing should be avoided

AbstractUnderstanding the factors that determine the abundance of populations is of key importance in conservation biology, ecology, and biogeography. For grassland‐associated species, such as the Hungarian meadow viper (Vipera ursinii rakosiensis), habitat management is particularly important. We aimed to study the effects of the three most common types of grassland management (grazing, mowing, and mowing + grazing) on the abundance of reptile species in meadow viper habitats in Kiskunság National Park, in Hungary. We surveyed grasslands repeatedly (n = 15 occasions) for reptiles in one autumn and one spring season in three 1‐ha quadrates per grassland management type. We recorded all reptiles and their activity related to operative temperatures and analyzed data by n‐mixture models. All reptile species known to occur in the habitats were observed during the surveys, but only the green lizard, sand lizard, and Hungarian meadow viper reached the minimum number of observations required for detailed analyses. Grazing had a strong positive effect on the abundance of Hungarian meadow vipers and sand lizards, while both mowing and mowing + grazing rotation had a negative effect. None of the grassland management types affected green lizard abundance. Our results suggest that grazing is the ideal type of grassland management for the endangered Hungarian meadow viper and the sand lizard. Mowing and mowing + grazing should be replaced by grazing to ensure the effectiveness of habitat management for conservation and to maintain healthy populations of grassland‐associated reptile species.

Environment drives color pattern polymorphism in sand lizards beyond the Gloger's rule

AbstractSpecies color and color pattern vary geographically contributing to environmental tolerance of the species to the fluctuating climate. In a constantly changing environment, the population remains polymorphic, when individuals that are not acclimated to the current environment can survive adverse time periods. Factors influencing color morph frequencies in populations affect spatial variation through local adaptation, which is in turn linked to large‐scale environmental gradients. The influence of environmental factors has not been adequately studied in many polymorphic organisms where the influence of sexual selection on the persistence of polymorphisms is widely recognized. We hypothesized that different color morphs of sand lizard are distributed throughout the Palearctic depending on different environmental conditions. The goal of this study was to examine if the range of morph composition in a color polymorphic lizard can be explained by geographic and climatic variation in the Palearctic. We used publicly available data on sand lizard occurrence from the Global Biodiversity Information Facility and environmental variables from WorldClim and SEDAC databases. We categorized sand lizards' photos to 10 discrete color morphs based on color and color pattern variation. We predicted the color morph distribution using maximum entropy models. We found that variations in morph distributions were mostly related to temperature seasonality, precipitation, elevation, and anthropogenic activities. Our findings support the relationship between environmental conditions and color morph distribution, implying that environmental selection acts differently on color morphs, most likely in conjunction with sexual selection.

Sex-Linked Loci on the W Chromosome in the Multi-Ocellated Racerunner (Eremias multiocellata) Confirm Genetic Sex-Determination Stability in Lacertid Lizards.

The multi-ocellated racerunner, Eremias multiocellata, was considered to have temperature-dependent sex determination (TSD), as its sex ratio can be influenced at different temperatures. However, such an observation contrasts with recent findings that suggest TSD is less common than previously thought. Here, a genotyping-by-sequencing (GBS) approach was employed to identify sex-linked markers in the E. multiocellata, for which the mechanism choice of TSD or GSD is still controversial. We preliminarily identified 119 sex-linked markers based on sex-associated sex-specific sequences, 97% of which indicated female heterogamety. After eliminating the false positives, 38 sex-linked markers were recognized, all of which showed the ZW/ZZ system. Then, eight of the novel markers were verified by PCR amplification from 15 populations of E. multiocellata, which support the GSD in E. multiocellata without geographic variation. To test the conservation of sex chromosome in Eremias, the eight markers were further cross-tested by PCR amplification in 10 individuals of the Mongolian racerunner (Eremias argus), two of which exhibited cross-utility. The novel sex-linked markers could be mapped on the W chromosome of the sand lizard (Lacerta agilis). Our finding that the sex-linked markers are shared in closely related species, along with a conserved synteny of the W chromosome, further supports the homology and conservation of sex chromosomes in the lacertid lizards.

Molecular characterization of Schellackia parasites in an urban population of sand lizards (Lacerta agilis) from Berlin, Germany

Lizards are hosts of several taxa of unicellular parasites of the phylum Apicomplexa, including Karyolysus, Schellackia, Lankesterella, and Hepatozoon. Parasite prevalence and the impact of infections on lizard biology remain largely unexplored. In this study, blood parasite infections were investigated in sand lizards (Lacerta agilis) from Berlin, Germany. Eighty-three individuals were investigated, and the detected blood parasites were identified as Schellackia sp. The combination of microscopic and molecular screening revealed a prevalence of 14.5%. Parasitemia values were low and most infections were subpatent. Phylogenetic analysis recovered a close relationship of the Schellackia parasites of this study with Schellackia sp. parasites of different Lacerta and Podarcis lizard species from Spain. Monitoring of Schellackia parasite infections in free-ranging lizards contributes to a better understanding of the distribution, diversity, and phylogenetic relationships of the neglected parasite taxon.

Quantitative genetics of breeding coloration in sand lizards; genic capture unlikely to maintain additive genetic variance

Sexual selection on fitness-determining traits should theoretically erode genetic variance and lead to low heritability. However, many sexually selected traits maintain significant phenotypic and additive genetic variance, with explanations for this “lek paradox” including genic capture due to condition-dependence, and breaks on directional selection due to environmental sources of variance including maternal effects. Here we investigate genetic and environmental sources of variance in the intrasexually selected green badge of the sand lizard (Lacerta agilis). The badge functions as a cue to male fighting ability in this species, and male–male interactions determine mate acquisition. Using animal models on a pedigree including three generations of males measured over an extensive 9-year field study, we partition phenotypic variance in both badge size and body condition into additive genetic, maternal, and permanent environmental effects experienced by an individual over its lifespan. Heritability of badge size was 0.33 with a significant estimate of underlying additive genetic variance. Body condition was strongly environmentally determined in this species and did not show either significant additive genetic variance or heritability. Neither badge size nor body condition was responsive to maternal effects. We propose that the lack of additive genetic variance and heritability of body condition makes it unlikely that genic capture mechanisms maintain additive genetic variance for badge size. That said, genic capture was originally proposed for male traits under female choice, not agonistic selection. If developmental pathways generating variance in body condition, and/or the covarying secondary sex trait, differ between inter- and intrasexual selection, or the rate at which their additive genetic variance or covariance is depleted, future work may show whether genic capture is largely restricted to intersexual selection processes.

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.

Sand lizards (Lacerta agilis) decrease nymphal infection prevalence for tick‐borne pathogens Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum in a coastal dune ecosystem

Abstract Understanding which factors determine tick‐borne disease hazard can contribute to effective disease control. In Europe, the hazard of the pathogens Borrelia burgdorferi s.l. and Anaplasma phagocytophilum is determined by local tick densities (mainly Ixodes ricinus) and the reservoir competence of the host species community. Sand lizards (Lacerta agilis) are common hosts for larvae and nymphs of I. ricinus and non‐competent reservoirs for both pathogens. Consequently, high relative abundance of L. agilis is hypothesized to be associated with lower infection prevalence in nymphs. Here, we aimed to test whether this effectively occurs in natural settings. We sampled different habitat types within a heterogenous dune landscape at the Dutch coast and estimated (1) L. agilis densities, (2) host community competence, (3) the density and infection prevalence of questing I. ricinus ticks and (4) the number and infection prevalence of ticks feeding on L. agilis. Captured L. agilis had high tick burdens and contributed substantially to feeding I. ricinus larvae in their natural habitat. B. burgdorferi s.l. and A. phagocytophilum were virtually absent from feeding larvae and nymphs. The nymphal infection prevalence of both pathogens in questing ticks was lower in habitat types where L. agilis was more abundant. Hence, L. agilis strongly reduced community competence. The density of questing nymphs was higher in habitat types with denser vegetation and also varied more between habitat types than infection prevalence. As a result, nymphal density had a stronger effect on the density of infected ticks than did nymphal infection prevalence. Synthesis and applications. Coastal dune habitats favourable for L. agilis have lower densities of questing nymphs and a lower human infection hazard. These results might be applicable to similar ecosystems where L. agilis is present. From a public health perspective, this underlines the importance of preserving early successional habitat, as encroaching shrubs are associated with higher tick‐borne disease hazard, and vegetation removal might be a solution to reduce hazard in coastal dunes. The high degree of spatial heterogeneity in the abundance of tick‐borne pathogens also poses opportunities to manage recreational activities to limit human exposure to tick‐borne diseases.

Chromosome-level genome assembly of Phrynocephalus forsythii using third-generation DNA sequencing and Hi-C analysis.

Phrynocephalus forsythii is a viviparous sand lizard that endemic to the Tarim Basin with a broad altitudinal range of 872 to 3100 m. Such variation in altitude and ecological variables can offer an opportunity to uncover genetic mechanisms of ectothermic adaptation to extreme environments at high- and low-altitude. Furthermore, the evolutionary relationship of karyotype with two different chromosome numbers (2n=46 or 2n=48) in the Chinese Phrynocephalus is unclear. In this study, a chromosome-level reference genome of P. forsythii was assembled. The genome assembly size was 1.82 Gb with a contig N50 length of 46.22Mb, 20,194 protein-coding genes were predicted and 95.50% of these genes were annotated in functional public databases. After cluster contigs into chromosome level using Hi-C paired-end reads, we found that two chromosomes of P. forsythii were originated from one ancestral chromosome of species with 46 chromosomes. Comparative genomic analysis revealed that numerous characteristics associated with high- or low-altitude adaptation, including energy metabolism pathways, hypoxic adaptation and immune, exhibit rapid changes or show signals of positive selection in the P. forsythii genome. This genome provides an excellent genome resource for the study of the karyotypes evolution and ecological genomics of Phrynocephalus.

Effect of MHC and inbreeding on disassortative reproduction: A data revisit, extension and inclusion of fertilization in sand lizards

The harmful effects of close inbreeding have been recognized for centuries and, with the rise of Mendelian genetics, was realized to be an effect of homozygosis. This historical background led to great interest in ways to quantify inbreeding, its depression effects on the phenotype and flow-on effects on mate choice and other aspects of behavioral ecology. The mechanisms and cues used to avoid inbreeding are varied and include major histocompatibility complex (MHC) molecules and the peptides they transport as predictors of the degree of genetic relatedness. Here, we revisit and complement data from a Swedish population of sand lizards (Lacerta agilis) showing signs of inbreeding depression to assess the effects of genetic relatedness on pair formation in the wild. Parental pairs were less similar at the MHC than expected under random mating but mated at random with respect to microsatellite relatedness. MHC clustered in groups of RFLP bands but no partner preference was observed with respect to partner MHC cluster genotype. Male MHC band patterns were unrelated to their fertilization success in clutches selected for analysis on the basis of showing mixed paternity. Thus, our data suggest that MHC plays a role in pre-copulatory, but not post-copulatory partner association, suggesting that MHC is not the driver of fertilization bias and gamete recognition in sand lizards.

Weather related detection probability of &lt;em&gt;Lacerta agilis&lt;/em&gt; LINNAEUS, 1758 within the core range in Western Germany

Weather conditions are important factors determining the activity, and consequently detection probability, of animals. Especially in ectotherms from temperate habitats, activity can vary strongly depending on weather. The sand lizard Lacerta agilis is a wide-ranging lizard that is often subject to environmental impact assessments due to its proximity to humans and prevalence as a candidate for compensatory measures according to the Flora and Fauna Habitat Directive of the European Union. Lacerta agilis has been studied extensively at certain edges of its distribution, but studies focusing on the core range have been rare. We use Bayesian models in order to identify the best explaining weather variables out of a large variety of available variables for a population of Lacerta agilis in western Germany. We furthermore depict their interactions with an easy-to-understand regression tree model. Sand lizards have shown to be more active during dry conditions with low windspeeds. They further are best found after sunny weather with temperatures around 20°C. Rainfall in the previous 24 hours also increases the detection probability. An unpruned regression tree reaffirms the results while giving concrete variable values and exploring how the values influence each other. Overall the method delivers a decision tree based on easy to obtain weather variables that allows for post- survey analysis and for determination of the best survey conditions.

Limited effects of inbreeding on breeding coloration.

Animal color signals may function as indicators of fighting ability when males compete for access to females. This allows opponents to settle aggressive interactions before they escalate into physical combat and injury. Thus, there may be strong directional selection on these traits, toward enhanced signal quality. This renders sexually selected traits particularly susceptible to inbreeding depression, due to relatively low ratios of additive genetic variance to dominance variance. We measured the effects of inbreeding on an intrasexually selected color signal (the badge) in a population of Swedish sand lizards (Lacerta agilis) using the Rhh software based on 17 to 21 microsatellites. Males of this sexually dichromatic species use the badge during aggressive interactions to display, and assess, fighting ability. We found negative effects of homozygosity on badge size, saturation, and brightness. However, no such effects were observed on color hue. Pairwise correlations between badge size, hue, and saturation were all statistically significant. Thus, the sand lizard "badge" is a multicomponent signal with variation explained by covariation in badge size, saturation, and color hue. Body mass corrected for skeletal size (body condition) positively predicted badge size and saturation, encouraging future research on the extent that sexual signals may convey information on multigene targets (i.e. "genic capture").