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Neftalí Sillero

Abstract

New records of the frog Hyla meridionalis have been reported on the Iberian Central mountain range, although it is not clear if those records correspond to an expansion process or to a lack of sampling. The species' global distribution was modelled to identify possible areas of expansion in the current environment and in a near future environment. To verify the effects of modelling a dynamic situation, the hypothetical expansion process from south to north was simulated in the current scenario. The species records were partitioned in four different datasets and modelled iteratively over a study area enclosing all records: records only from North Africa, from North Africa and South Iberian Peninsula, from North Africa and all the Iberian Peninsula, and from the entire distribution. The complete dataset was also used to extrapolate the model to a current and future global environmental scenarios. The models were compared by subtraction per pairs and by Cohen's Kappa. No spatio-temporal trends were detected in species records; therefore, the hypothesis of a recent expansion is nor supported. The species spread only to the Mediterranean part of the Iberian Peninsula when modelling only with African records, and to Europe when modelling also with Iberian records. The extrapolation models were moderately similar: large suitable areas were predicted in all the continents. Temperature variables contributed more to models. The species can expand to new suitable areas, although it is not possible to know if it would expand outside the biogeographical regions where the species is present.

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Neftalí Sillero

Abstract

Road-kills are the greatest source of direct human-induced wildlife mortality, especially in amphibians. Country roads could act as the most important source of mortality when main roads act as strong barriers hampering the migration movements of some species. Mortality patterns of amphibians on country roads (1380 km) were studied in Salamanca (Spain) in order to quantify the mortality levels, to test the effects of sex and age factors on road-kills, to determine the spatial distribution patterns of road-kills, and to identify routes of migration through a friction map and hotspots of road-kills. From a total of 819 records of amphibians, 38.1% were road-killed and 61.9% were live. Fourteen amphibian species were recorded during the surveys (10 anurans and four urodeles). The species more affected by road-kills were the anurans Bufo calamita, Pelobates cultripes and B. bufo (38.5, 23.4 and 11.9%, respectively). Females had higher incidence of road-kills than males, due to the differential activity patterns of both sexes during the reproductive period. Adults were the most common age period and also the most road-killed. The spatial distribution patterns of live and road-killed records were clustered. On the sampled roads, there were 0.23 road-kills per kilometre and 52 hotspots of road-kills. The friction map showed that most of the road-killed and live specimens were located on migration routes crossing suitable habitats. Conservation measures should be implemented in these areas, as these mortality patterns may be causing significant negative impacts at the population level.

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Cátia Matos, Neftalí Sillero and Elena Argaña

Animal mortality caused by vehicle collisions is one of the main ecological impacts of roads. Amphibians are the most affected group and road fatalities have a significant impact on population dynamics and viability. Several studies on Iberian amphibians have shown the importance of country roads on amphibian road mortality, but still, little is known about the situation in northern Portugal. By being more permeable to amphibian passage, country roads represent a greater source of mortality than highways, which act as barriers. Thus, mitigation measures should be applied, but due to the extensive road network, the identification of precise locations (hotspots) and variables related to animal-vehicle collision is needed to plan these measures successfully. The aim of the study was to analyse the spatial occurrence and related factors linked to amphibian mortality on a number of country roads in northern Portugal, using spatial statistics implemented in GIS and applying a binary logistical regression. We surveyed 631 km of road corresponding to seven transects, and observed 404 individual amphibians: 74 (18.3%) alive and 330 (81.7%) road-killed. Bufo bufo represented 80% of the mortality records. Three transects showed clustered distribution of road-kills, and broadleaved forests and road ditches were the most important factors associated with hotspots of road-kill. Logistic regression models showed that habitat quality, Bufo bufo’s habitat preferences, and road ditches are positively associated with amphibians’ road mortality in northern Portugal, whereas average altitude and length of walls were negatively associated. This study is a useful tool to understand spatial occurrence of amphibian road-kills in the face of applying mitigation measures on country roads from northern Portugal. This study also considers the necessity of assessing the condition of amphibian local populations to understand their road-kills spatial patterns and the urgency to apply mitigation measures on country roads.

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Eduardo García-Meléndez, Raquel Ribeiro, José Carlos Brito and Neftalí Sillero

Abstract

Altitude is an important factor when explaining species distributions. However, many biogeographical studies register altitude directly through topographic maps; a time-consuming manual process prone to mistakes. Currently, GIS and DEMs allow this work to be done more efficiently. Two methods for registering altitude for locations of amphibians and reptiles in the Iberian Peninsula were compared in order to evaluate their efficiency and similarity: manually through topographic maps, and automatically with a GIS, where two DEMs were analysed: the SRTM DEM and a DEM generated through topographic maps. The SRTM altitudes were similar to those recorded by the manual method (only Rana perezi presented differences), whereas the other DEM had differences in almost all amphibians and three reptiles. The differences between both DEMs corresponded mostly to rivers and band effect of radar sensor. The GIS method was faster, efficient and no time was consumed in searching and correcting human errors.

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Ben Wielstra, Neftalí Sillero, Judit Vörös and Jan W. Arntzen

In the recently published New Atlas of Amphibians and Reptiles of Europe (Sillero et al., 2014a), the distribution of the newt genus Triturus was not resolved at the level of the species. The main reason for this was the lack of high quality distribution data from in and around the parapatric contact zones between species, where interspecific hybridization occurs. We are working extensively on Triturus and the (particularly genetic) data we have accumulated allow us to map the individual Triturus species at the appropriate scale. We here provide a database composed of distribution data for the individual species, at generally high resolution, particularly from in and around contact zones. Based on this database we produce maps at the 50 × 50 km UTM grid resolution as used in the new atlas and highlight those grid cells in which more than one Triturus species occurs.

Open Access

Neftalí Sillero, Marco Amaro Oliveira, Pedro Sousa, Fátima Sousa and Luís Gonçalves-Seco

The Societas Europaea Herpetologica (SEH) decided in 2006 through its Mapping Committee to implement the New Atlas of Amphibians and Reptiles of Europe (NA2RE: http://na2re.ismai.pt) as a chorological database system. Initially designed to be a system of distributed databases, NA2RE quickly evolved to a Spatial Data Infrastructure, a system of geographically distributed systems. Each individual system has a national focus and is implemented in an online network, accessible through standard interfaces, thus allowing for interoperable communication and sharing of spatial-temporal data amongst one another. A Web interface facilitates the access of the user to all participating data systems as if it were one single virtual integrated data-source. Upon user request, the Web interface searches all distributed data-sources for the requested data, integrating the answers in an always updated and interactive map. This infrastructure implements methods for fast actualisation of national observation records, as well as for the use of a common taxonomy and systematics. Using this approach, data duplication is avoided, national systems are maintained in their own countries, and national organisations are responsible for their own data curation and management. The database could be built with different representation levels and resolution levels of data, and filtered according to species conservation matters. We present the first prototype of NA2RE, composed of the last data compilation performed by the SEH (Sillero et al., 2014). This system is implemented using only open source software: PostgreSQL database with PostGIS extension, Geoserver, and OpenLayers.

Full Access

Ben Wielstra, Daniele Canestrelli, Milena Cvijanović, Mathieu Denoël, Anna Fijarczyk, Daniel Jablonski, Marcin Liana, Borislav Naumov, Kurtuluş Olgun, Maciej Pabijan, Alice Pezzarossa, Georgi Popgeorgiev, Daniele Salvi, Yali Si, Neftalí Sillero, Konstantinos Sotiropoulos, Piotr Zieliński and Wiesław Babik

Abstract

The ‘smooth newt’, the taxon traditionally referred to as Lissotriton vulgaris, consists of multiple morphologically distinct taxa. Given the uncertainty concerning the validity and rank of these taxa, L. vulgaris sensu lato has often been treated as a single, polytypic species. A recent study, driven by genetic data, proposed to recognize five species, L. graecus, L. kosswigi, L. lantzi, L. schmidtleri and a more restricted L. vulgaris. The Carpathian newt L. montandoni was confirmed to be a closely related sister species. We propose to refer to this collective of six Lissotriton species as the smooth newt or Lissotriton vulgaris species complex. Guided by comprehensive genomic data from throughout the range of the smooth newt species complex we 1) delineate the distribution ranges, 2) provide a distribution database, and 3) produce distribution maps according to the format of the New Atlas of Amphibians and Reptiles of Europe, for the six constituent species. This allows us to 4) highlight regions where more research is needed to determine the position of contact zones.

Open Access

Neftali Sillero, João Campos, Anna Bonardi, Claudia Corti, Raymond Creemers, Pierre-Andre Crochet, Jelka Crnobrnja Isailović, Mathieu Denoël, Gentile Francesco Ficetola, João Gonçalves, Sergei Kuzmin, Petros Lymberakis, Philip de Pous, Ariel Rodríguez, Roberto Sindaco, Jeroen Speybroeck, Bert Toxopeus, David R. Vieites and Miguel Vences

A precise knowledge of the spatial distribution of taxa is essential for decision-making processes in land management and biodiversity conservation, both for present and under future global change scenarios. This is a key base for several scientific disciplines (e.g. macro-ecology, biogeography, evolutionary biology, spatial planning, or environmental impact assessment) that rely on species distribution maps. An atlas summarizing the distribution of European amphibians and reptiles with 50 × 50 km resolution maps based on ca. 85 000 grid records was published by the Societas Europaea Herpetologica (SEH) in 1997. Since then, more detailed species distribution maps covering large parts of Europe became available, while taxonomic progress has led to a plethora of taxonomic changes including new species descriptions. To account for these progresses, we compiled information from different data sources: published in books and websites, ongoing national atlases, personal data kindly provided to the SEH, the 1997 European Atlas, and the Global Biodiversity Information Facility (GBIF). Databases were homogenised, deleting all information except species names and coordinates, projected to the same coordinate system (WGS84) and transformed into a 50 × 50 km grid. The newly compiled database comprises more than 384 000 grid and locality records distributed across 40 countries. We calculated species richness maps as well as maps of Corrected Weighted Endemism and defined species distribution types (i.e. groups of species with similar distribution patterns) by hierarchical cluster analysis using Jaccard’s index as association measure. Our analysis serves as a preliminary step towards an interactive, dynamic and online distributed database system (NA2RE system) of the current spatial distribution of European amphibians and reptiles. The NA2RE system will serve as well to monitor potential temporal changes in their distributions. Grid maps of all species are made available along with this paper as a tool for decision-making and conservation-related studies and actions. We also identify taxonomic and geographic gaps of knowledge that need to be filled, and we highlight the need to add temporal and altitudinal data for all records, to allow tracking potential species distribution changes as well as detailed modelling of the impacts of land use and climate change on European amphibians and reptiles.