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Augusto Gentilli, Roberto Sacchi, Marco Mangiacotti and Stefano Scali

Abstract

Interspecific competition in contact areas is a major topic in ecological studies. A number of studies were carried out on European vipers, focusing on contact areas between two or three species characterized as appropriate by ecological needs more or less similar. The aim of this study is to extend the analysis of this topic to the case of Vipera aspis and V. berus in an alpine area of northern Italy, by comparing suitability models to verify which ecological factors affect their occurrence and to assess a possible niche separation. Potential distribution was modelled using the maximum entropy method, using six non-correlated ecogeographical variables as predictors. The models fitted well for both species (mean AUC = 0.926; 87.4% of testing data correctly classified). The most informative variables were: habitat, altitude and solar radiation for the asp viper; altitude and habitat for the adder. Deciduous woods, meadows and urban areas had a positive effect on V. aspis distribution as wetlands, meadows and rocks vegetation did on V. berus. However, the variable best separating the species was the elevation, the adder occurring more frequently at higher altitude than the asp viper. Our data showed that the two vipers were mutually exclusive, as already observed by Saint Girons in 1975. Vipera aspis is more thermophilic and lives at low altitude, while Vipera berus lives under cool and humid areas typical of alpine pastures. A similar pattern were found in the contact areas between European vipers belonging to the V. aspis and Pelias group respectively.

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Roberto Sacchi, Daniele Pellitteri Rosa, Fabio Pupin and Mauro Fasola

Abstract

We used geometric morphometric analysis to investigate latitudinal variation in size and shape of carapace and plastron of 111 Testudo hermanni hermanni (60 males and 51 females) collected in 6 different Italian regions. Basing on a sample of 14 landmarks for carapace and 18 landmarks for plastron, we showed that the size and shape of both sexes changed according to a North-South cline following the Bergmann's rule, tortoises of Northern Italy being 1.1-1.2 larger than that of Southern Italy. Shape variation was higher in carapace probably because sexual selection in this species acts stronger on plastron than on carapace shape.

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Roberto Sacchi, Marco Mangiacotti, Stefano Scali, Michele Ghitti, Beatrice Bindolini and Marco A.L. Zuffi

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.

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Pietro Angelo Nardi, Elisa Altobelli, Paolo Galeotti, Fabio Pupin, Roberto Sacchi, Mauro Fasola and Diego Rubolini

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Stefano Scali, Diego Rubolini, Mauro Fasola, Edoardo Razzetti, Roberto Sacchi, Fabio Pupin, Paolo Galeotti and Augusto Gentilli

Abstract

Permanent colour polymorphism in lizards is maintained by complex interactions between environmental pressures and physiological traits (such as immune responsiveness) that differ among morphs. In this study we investigated whether T-cell mediated immune response vary among male colour morphs in the trimorphic (white, yellow and red) common wall lizard, Podarcis muralis. We found that yellow males showed a lower immune response compared to both red and white males, whose responses were similar. Thus, immune responsiveness is morph-specific in male common wall lizards, suggesting that this physiological trait could play an important role in maintaining colour polymorphism in this species. Moreover, immune responsiveness significantly increased with increasing male size, irrespective of colour morph, indicating that it could be regarded as a condition-dependent trait.

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Fabio Pupin, Roberto Sacchi, Stefano Scali, Alessandra Binda, Marco Zuffi, Mauro Fasola, Eleonora Boncompagni and Paolo Galeotti

Abstract

The morphology of erythrocytes, trombocytes, monocytes, basophils and lymphocytes on Moorish geckos (Tarentola mauritanica) is quite similar to that of other reptiles, even though some peculiarities were detected for heterophils and eosinophils. Moreover, we found a fourth type of granulocyte whose morphology highly differs from both heterophils and eosinophils. Sexually-based differences in the relative abundance of different types of leukocytes was detected: lymphocytes were the most frequent in females, while heterophils and eosinophils prevailed in males. Interestingly, in most individuals we found intra-erythrocytic vacuoles whose structure is similar to that previously described as Chelonoplasma in tortoises and Serpentoplasma in snakes.

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Mauro Fasola, Daniele Pellitteri-Rosa, Fabio Pupin, Stefano Scali, Roberto Sacchi, Franco Bernini, Augusto Gentilli and Edoardo Razzetti

Abstract

Repatriations and translocations are among the most frequent actions deployed for conservation of amphibians all over the world. However, very few studies have analysed the effectiveness of these actions. The aims of this study were i) to measure the success of repatriations of Rana latastei carried out within a conservation project in Lombardy (Northern Italy) from 1999 to 2001, and ii) to analyse how the environmental factors affected repatriation success. Eighteen ponds were surveyed from February to April 2006, for an overall of 45 field surveys. Each pond was carefully checked for frogs and egg masses. We classified each pond as newly excavated or pre-existing according to habitat management actions and we measured 16 variables concerning micro- and macro-habitat characteristics, human disturbance and presence of predators. Rana latastei was found in 33.3% of monitored sites and the repatriation outcome of tadpole release did not differ between newly excavated and non managed ponds. Habitat variables influenced the success of repatriations, which increased in sites with higher percentage of woodlands. Finally, repatriation outcome was also negatively influenced by human disturbance and predator occurrence.

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Daniele Pellitteri-Rosa, Veronica Maiocchi, Stefano Scali, Luca Racina, Luca Cavigioli, Roberto Sacchi, Mauro Fasola, Paolo Galeotti, Augusto Gentilli, Serena Tettamanti and Fabio Pupin

Abstract

Photographic identification is a promising marking technique alternative to the toe-clipping, since it is completely harmless, cheap, and it allows long time identification of individuals. Its application to ecological studies is mainly limited by the time consuming to compare pictures within large datasets and the huge variation of ornamentation patterns among different species, which prevent the possibility that a single algorithm can effectively work for more than few species. Scales of Reptiles offer an effective alternative to ornamentations for computer aided identification procedures, since both shape and size of scales are unique to each individual, thus acting as a fingerprint like ornamentation patterns do. We used the Interactive Individual Identification System (I3S) software to assess whether different individuals of two species of European lizards (Podarcis muralis and Lacerta bilineata) can be reliably photographically identified using the pattern of the intersections among pectoral scales as fingerprints. We found that I3S was able to identify different individuals among two samples of 21 individuals for each species independently from the error associated to the ability of the operators in collecting pictures and in digitizing the pattern of intersections among pectoral scales. In a database of 1043 images of P. muralis collected between 2007 and 2008, the software recognized 98% of recaptures within each year, and 99% of the recaptures between years. In addition, 99% and 96% of matches were ranked among the top five, and no more than 5 minutes were needed for digitizing and processing each image. The lepidosis of reptiles is a reliable alternative to ornamentation patterns in photographic identification of reptiles, which can be effectively analysed using the I3S software. This result represents a significant improvement in photographic identification of reptiles since (i) this procedure can be easily extended to most other species of reptiles, (ii) all kind of individuals within a species can be marked (i.e., young, subadults and adults) despite the differences in ornamentation patterns, and (iii) it is the only technique for species, like the western green lizard, which lack a clear ornamentation pattern.