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Scali S.,Museo Civico di Storia Naturale di Milan | Sacchi R.,University of Pavia | Gentilli A.,University of Pavia
Amphibia Reptilia | Year: 2011

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. © 2011 Brill Academic Publishers.


Hamdan B.,Federal University of Rio de Janeiro | Hamdan B.,Colecao Cientifica Instituto Vital Brazil | Scali S.,Museo Civico di Storia Naturale di Milan | Fernandes D.S.,Federal University of Rio de Janeiro
Zootaxa | Year: 2014

The snake genus Chironius Fitzinger, 1826 is endemic to the Neotropical region, occurring from Honduras to Uruguay and northeastern Argentina. Some species of the genus have taxonomic and/or nomenclatural problems, such as C. flavo-lineatus which lacks agreement in the literature about its authorship and type locality. Some researchers have been sug-gesting Jan (1863) as the author of the species since he first described C. flavolineatus based on two specimens. However, other researchers report that Jan's description is so incomplete that it is not possible to ascertain what snake he had in mind and therefore suggest Boettger (1885) as the author, since he was the first to provide a detailed description of the species. In the present study one of the syntypes of C. flavolineatus, supposedly destroyed in Second World War, was found. Thus, the taxonomic identity of C. flavolineatus was redefined, its lectotype was designated and the authorship of the taxa is attributed to Jan (1863). Copyright © 2014 Magnolia Press.


PubMed | University Grenoble Alpes, University of Milan Bicocca and Museo Civico di Storia Naturale di Milan
Type: Journal Article | Journal: Global change biology | Year: 2016

Despite the recognition that some species might quickly adapt to new conditions under climate change, demonstrating and predicting such a fundamental response is challenging. Morphological variations in response to climate may be caused by evolutionary changes or phenotypic plasticity, or both, but teasing apart these processes is difficult. Here, we built on the number of thoracic vertebrae (NTV) in ectothermic vertebrates, a known genetically based feature, to establish a link with body size and evaluate how climate change might affect the future morphological response of this group of species. First, we show that in old-world salamanders, NTV variation is strongly related to changes in body size. Secondly, using 22 salamander species as a case study, we found support for relationships between the spatial variation in selected bioclimatic variables and NTV for most of species. For 44% of species, precipitation and aridity were the predominant drivers of geographical variation of the NTV. Temperature features were dominant for 31% of species, while for 19% temperature and precipitation played a comparable role. This two-step analysis demonstrates that ectothermic vertebrates may evolve in response to climate change by modifying the number of thoracic vertebrae. These findings allow to develop scenarios for potential morphological evolution under future climate change and to identify areas and species in which the most marked evolutionary responses are expected. Resistance to climate change estimated from species distribution models was positively related to present-day species morphological response, suggesting that the ability of morphological evolution may play a role for species persistence under climate change. The possibility that present-day capacity for local adaptation might help the resistance response to climate change can be integrated into analyses of the impact of global changes and should also be considered when planning management actions favouring species persistence.


Curcio F.F.,Federal University of Mato Grosso | Scali S.,Museo Civico di Storia Naturale di Milan | Rodrigues M.T.,University of Sao Paulo
Herpetological Monographs | Year: 2015

We reassessed the taxonomic status of the xenodontine snake Erythrolamprus bizona Jan (1863) based on a comprehensive review of literature records and comparative material. Our data demonstrate that the original diagnosis does not allow the unambiguous attribution of the name E. bizona to any population of the genus. After a thorough investigation in European institutions, we recovered two syntypes of the E. bizona type-series, confirming its composite nature. To circumvent the problem, we herein designate a lectotype for the species, providing a reformulated diagnosis and a detailed redescription. The lectotype represents one of the rare remaining specimens used in Giorgio Jan's original descriptions during the second half of 19th century, and is housed in the Museo Civico di Storia Naturale di Milano, Milan, Italy. For more than seven decades, herpetologists have assumed that such material had been lost forever due to bombings of World War II. Nonetheless, our finding corroborates recent studies demonstrating that at least some of Jan's snake types still exist for taxonomic research. Finally, we discuss the geographic congruence of the frequency distributions of segmental counts under an integrative approach aiming to maintain nomenclatural stability without ignoring preliminary evidence of taxonomic diversity. © 2015 by The Herpetologists' League, Inc.


Stiassny M.L.J.,American Museum of Natural History | De Marchi G.,Museo Civico di Storia Naturale di Milan | Lamboj A.,University of Vienna
Zootaxa | Year: 2010

A new species of cichlid fish is described from a small, endorheic lake (Lake Abaeded), situated some 30 m below sea level in the Danakil Depression of Eritrea (East Africa). Danakilia dinicolai is readily distinguished from its congener, D. franchettii, on the basis of body proportions and in the possession of markedly longer pectoral fins at all sizes. Additionally, oral dentition is more robust than that of its congener, and the lower pharyngeal jaw is markedly hypertrophied and covered with considerably finer and more densely implanted teeth on the posterior field of the jaw. Copyright © 2010.


Mangiacotti M.,Museo Civico di Storia Naturale di Milan | Scali S.,Museo Civico di Storia Naturale di Milan | Sacchi R.,University of Pavia | Bassu L.,Sezione Sardegna | And 2 more authors.
PLoS ONE | Year: 2013

Patch context is a way to describe the effect that the surroundings exert on a landscape patch. Despite anthropogenic context alteration may affect species distributions by reducing the accessibility to suitable patches, species distribution modelling have rarely accounted for its effects explicitly. We propose a general framework to statistically detect the occurrence and the extent of such a factor, by combining presence-only data, spatial distribution models and information-theoretic model selection procedures. After having established the spatial resolution of the analysis on the basis of the species characteristics, a measure of anthropogenic alteration that can be quantified at increasing distance from each patch has to be defined. Then the distribution of the species is modelled under competing hypotheses: H0, assumes that the distribution is uninfluenced by the anthropogenic variables; H1, assumes the effect of alteration at the species scale (resolution); and H2, H3... Hn add the effect of context alteration at increasing radii. Models are compared using the Akaike Information Criterion to establish the best hypothesis, and consequently the occurrence (if any) and the spatial scale of the anthropogenic effect. As a study case we analysed the distribution data of two insular lizards (one endemic and one naturalised) using four alternative hypotheses: no alteration (H0), alteration at the species scale (H1), alteration at two context scales (H2 and H3). H2 and H3 performed better than H0 and H1, highlighting the importance of context alteration. H2 performed better than H3, setting the spatial scale of the context at 1 km. The two species respond differently to context alteration, the introduced lizard being more tolerant than the endemic one. The proposed approach supplies reliably and interpretable results, uses easily available data on species distribution, and allows the assessing of the spatial scale at which human disturbance produces the heaviest effects. © 2013 Mangiacotti et al.


Marchi G.D.,University of Pavia | Fasola M.,University of Pavia | Chiozzi G.,Museo Civico di Storia Naturale di Milan | Bellati A.,University of Pavia | Galeotti P.,University of Pavia
Waterbirds | Year: 2012

Determining the sex of Crab Plovers (Dromas ardeola) based on morphology has, hitherto, proven difficult. Here, six morphological traits (head-bill length, bill length, bill depth, wing chord, tarsus length and weight) of 39 molecularly or behaviorally sexed breeding Crab Plovers were compared in order to find a reliable morphometric way to determine their sex. Males were significantly larger than females in all traits, except tarsus length, and especially in traits related to head and bill size, where males were 6.8 to 11.4% larger than females. Discriminant Function Analysis correctly classified 97.4% of birds using only bill depth and bill length, providing an efficient tool for sexing Crab Plovers in the hand.


Cesari M.,University of Modena and Reggio Emilia | Maistrello L.,University of Modena and Reggio Emilia | Ganzerli F.,University of Modena and Reggio Emilia | Dioli P.,Museo Civico di Storia Naturale di Milan | And 2 more authors.
Journal of Pest Science | Year: 2015

The brown marmorated stink bug, Halyomorpha halys, is an agricultural and household pest native of far East. In the last years, it has spread to and established in countries outside its area of origin, most notably in North America (United States and Canada), causing severe economic losses in agricultural crops. Recently, H. halys has been found in Europe (Switzerland, Germany, France, Hungary, and Greece) and since September 2012, it has also been found in Italy. However, the modalities of introduction and spreading of this pest on the Italian territory are unknown. Tracing back the diffusion modes of the species by analyzing the genetic structure and composition of populations in their initial phase of colonization could be useful also in the view to implement better pest control strategies. The present study aimed to identify the potential pathways of entry of H. halys by detecting the genetic diversity of specimens collected from Northern Italy and Canton Ticino (Southern Switzerland). The analyses of 1,175 base pairs of mtDNA cytochrome c oxidase I and II genes (cox1 and cox2) on 42 specimens led to the identification of four combined haplotypes: one, found in Emilia Romagna region, is the same found in China and North America but never observed before in Europe. The other combined haplotypes are new but consistent in part with haplotypes previously found in Switzerland. Present data indicate that the Italian invasion may have occurred from two different pathways, both from Switzerland and from Asia and/or North America. © 2014, Springer-Verlag Berlin Heidelberg.


Ficetola G.F.,University of Milan Bicocca | Bonardi A.,University of Milan Bicocca | Colleoni E.,University of Milan Bicocca | Padoa-Schioppa E.,University of Milan Bicocca | Scali S.,Museo Civico di Storia Naturale di Milan
Evolutionary Biology | Year: 2013

The evolution of sexual dimorphism is an important topic of evolutionary biology, but few studies have investigated the determinants of sexual dimorphism over broad phylogenetic scales. The number of vertebrae is a discrete character influencing multiple traits of individuals, and is particularly suitable to analyze processes determining morphological variation. We evaluated the support of multiple hypotheses concerning evolutionary processes that may cause sexual dimorphism in the number of caudal vertebrae in Urodela (tailed amphibians). We obtained counts of caudal vertebrae from >2,000 individuals representing 27 species of salamanders and newts from Europe and the Near East, and integrated these data with a molecular phylogeny and multiple information on species natural history. Per each species, we estimated sexual dimorphism in caudal vertebrae number. We then used phylogenetic least squares to relate this sexual dimorphism to natural history features (courtship complexity, body size dimorphism, sexual ornamentation, aquatic phenology) representing alternative hypotheses on processes that may explain sexual dimorphism. In 18 % of species, males had significantly more caudal vertebrae than females, while in no species did females have significantly more caudal vertebrae. Dimorphism was highest in species where males have more complex courtship behaviours, while the support of other candidate mechanisms was weak. In many species, males use the tail during courtship displays, and sexual selection probably favours tails with more vertebrae. Dimorphism for the number of tail vertebrae was unrelated to other forms of dimorphism, such as sexual ornamentation or body size differences. Multiple sexually dimorphic features may evolve independently because of the interplay between sexual selection, fecundity and natural selection. © 2012 Springer Science+Business Media New York.


PubMed | Museo Civico di Storia Naturale di Milan
Type: Journal Article | Journal: PloS one | Year: 2016

Patch context is a way to describe the effect that the surroundings exert on a landscape patch. Despite anthropogenic context alteration may affect species distributions by reducing the accessibility to suitable patches, species distribution modelling have rarely accounted for its effects explicitly. We propose a general framework to statistically detect the occurrence and the extent of such a factor, by combining presence-only data, spatial distribution models and information-theoretic model selection procedures. After having established the spatial resolution of the analysis on the basis of the species characteristics, a measure of anthropogenic alteration that can be quantified at increasing distance from each patch has to be defined. Then the distribution of the species is modelled under competing hypotheses: H0, assumes that the distribution is uninfluenced by the anthropogenic variables; H1, assumes the effect of alteration at the species scale (resolution); and H2, H3 Hn add the effect of context alteration at increasing radii. Models are compared using the Akaike Information Criterion to establish the best hypothesis, and consequently the occurrence (if any) and the spatial scale of the anthropogenic effect. As a study case we analysed the distribution data of two insular lizards (one endemic and one naturalised) using four alternative hypotheses: no alteration (H0), alteration at the species scale (H1), alteration at two context scales (H2 and H3). H2 and H3 performed better than H0 and H1, highlighting the importance of context alteration. H2 performed better than H3, setting the spatial scale of the context at 1 km. The two species respond differently to context alteration, the introduced lizard being more tolerant than the endemic one. The proposed approach supplies reliably and interpretable results, uses easily available data on species distribution, and allows the assessing of the spatial scale at which human disturbance produces the heaviest effects.

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