47 research outputs found

    An updated dichotomous key to the snakes of Europe

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    This work presents an updated dichotomous key to all snake species of Europe, based on morpho-logical, morphometric and distributional characters. It gathers data from both the last dichotomous keys concerning European snake species and every following paper giving updates on taxonomic classification or the occurrence of new allochthonous species. The key includes 58 snake taxa, in-cluding 57species and one still unnamed taxon, distributed on the European territory, and photo-graphic material for each species. The aim of this paper is to make the identification of all Europe-an snake species through a single manuscript more accessible, not only for researchers, but also for citizen science, thus enhancing data collection and assist species conservation

    Una nuova popolazione isolata di xenopo liscio in Sicilia sud-occidentale

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    African clawed frog is a sub-saharan native anuran that has been introduced in various states of the old and the new world. The only Italian population of this species is located in western Sicily, and it is known as the European clawed frog population with wider distribution area. This paper describes a new Sicilian population of this species, and sets out to verify the effective isolation from the currently known distribution. The new site is a disused swimming pool, located near the mouth of the Belice River (province of Trapani), 31 km away from the nearest edge of the African clawed frog distribution area. To test whether this new population is the result of natural expansion of its range have been checked 21 control sites, arranged in a suitable area near the new site and along the basin of the Belice River, whose upper course is included in the Sicilian range of this species. The surveys in the control sites did not reveal the presence of clawed frogs, therefore, it seems doubtful the hypothesis of natural expansion along the Belice River basin and plausible the occurrence of a man-mediated introduction event

    The Endangered Sardinian Grass Snake: Distribution Update, Bioclimatic Niche Modelling, Dorsal Pattern Characterisation, and Literature Review

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    The Sardinian grass snake, Natrix helvetica cetti, is an endangered endemic snake subspecies with a restricted and highly fragmented geographic distribution. Information on its ecology and detailed geographic distribution are scarce and may negatively impact on its conservation status. Therefore, a literature review on its taxonomy, morphology, ecology, and conservation is presented here. Moreover, field records from the authors, citizen science and the existing literature provide an updated geographic distribution highlighting its presence within 13 new and 7 historic 10 x 10 km cells. Bioclimatic niche modelling was then applied to explore patterns of habitat suitability and phenotypic variation within N. h. cetti. The geographic distribution of the species was found to be positively correlated with altitude and precipitation values, whereas temperatures howed a negative correlation. Taken together, these outcomes may explain the snake’s presence, particularly in eastern Sardinia. In addition, analysis of distribution overlap with the competing viperine snake (N. maura) and the urodeles as possible overlooked trophic resources (Speleomantes spp. and Euproctus platycephalus) showed overlaps of 66% and 79%, respectively. Finally, geographical or bioclimatic correlations did not explain phenotypic variation patterns observed in this highly polymorphic taxon. Perspectives on future research to investigate N. h. cetti’s decline and support effective conservation measures are discussed

    Aliens Coming by Ships: Distribution and Origins of the Ocellated Skink Populations in Peninsular Italy

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    The ocellated skink (Chalcides ocellatus) is a widespread lizard, naturally distributed between the Maghreb and coastal Pakistan, with few insular populations in the Mediterranean coastal area. Some populations of this species have also been recorded in peninsular Italy, Campania and Southern Tuscany due to accidental introductions via touristic and commercial routes. In this work, we conducted genetic analyses on mitochondrial DNA COXI, cytb and 16S mtDNA genes on a sample of Italian insular and peninsular populations. Differently from what previously suggested, the nucleus in Portici (Southern Italy) may have originated from Sardinia. The intense trade and touristic traffic between Sardinia and Southern Tuscany may have been responsible for the introduction of this lizard also to Central Italy

    The spreading of the invasive Italian wall lizard on vulcano, the last Island inhabited by the critically endangered Aeolian wall lizard

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    The Aeolian Wall Lizard (Podarcis raffoneae) is an endemic species of the Aeolian Archipelago of Italy (Mediterranean Sea). Its distribution is limited to three islets and two relict populations on a relatively large island: Vulcano (a population on the summit of Gran Cratere volcano and another on Capo Grosso promontory). The critically endangered Aeolian Wall Lizard is threatened by the introduction of the Italian Wall Lizard (Podarcis siculus), which successfully competes and hybridizes with the endemic lizard. The invasive lizard is widespread on Vulcano, although the literature does not provide the exact distribution. Our first aim was updating the distribution of the Italian Wall Lizard on Vulcano, with special attention to the last enclaves of the Aeolian Wall Lizard. Our second purpose was investigating the factors determining this distribution range. In the spring of 2016, we surveyed the Italian Wall Lizard distribution on Vulcano, considering 10 human-related and 10 natural areas, including Gran Cratere volcano and Capo Grosso promontory. We recorded the presence of the invasive Italian Wall Lizard in each survey area. As a consequence, the Aeolian Wall Lizard populations of Vulcano face an imminent extinction risk. The main factors increasing the presence probability of this invasive lizard on Vulcano were the nearness to the harbor (the introduction gateway) and the urbanization degree (the invasion pathway). Therefore, we suggest the implementation of a control plan simultaneously acting on the areas of sympatry (mostly Capo Grosso promontory), the introduction gateway (Vulcano harbor), and the source populations (urban areas)
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