21 research outputs found
Evaluating taxonomic inflation: towards evidence-based species delimitation in Eurasian vipers (Serpentes: Viperinae)
International audienceThe designation of taxonomic units has important implications for the understanding and conservation ofbiodiversity. Eurasian vipers are a monophyletic group of viperid snakes (Serpentes, Viperinae), currently comprising fourgenera (Daboia, Macrovipera, Montivipera and Vipera) and up to 40 species. Taxonomic units have been described usinga wide variety of methods and criteria, and consequently, considerable controversy still surrounds the validity of somecurrently listed species. In order to promote a consensus- and evidence-based taxonomy of Eurasian vipers, we analysedpublished mitochondrial and nuclear DNA sequences for this group to reconstruct phylogenetic relationships among currentlyrecognized viper species.We also compiled information on external morphology to assess their morphological distinctiveness.Phylogenetic inference based on mtDNA sequences shows contrasting levels of divergence across genera and species andidentifies several instances of non-monophyly in described species. Nuclear DNA sequences show extremely low levels ofgenetic variation, with a widespread pattern of allele sharing among distant species, and even among genera. Revision ofmorphological data shows that most species designations rely on scalation traits that overlap extensively among species ofthe same genus. Based on our combined assessment, we recognize 15 taxa as valid species, three taxa which likely representspecies complexes, 17 taxa of doubtful validity as species, and five taxa for which species status is maintained but furtherresearch is highly recommended to assess taxonomic arrangements. We stress the need to implement integrative taxonomicapproaches for the recognition of evidence-based taxonomic units in Eurasian viper
Factor in Fear: Interference Competition in Polymorphic Spadefoot Toad Tadpoles and Its Potential Role in Disruptive Selection
Disruptive selection arises when extreme phenotypes have a fitness advantage compared to more-intermediate phenotypes. Theory and evidence suggest that intraspecific resource competition is a key driver of disruptive selection. However, while competition can be indirect (exploitative) or direct (interference), the role of interference competition in disruptive selection has not been tested, and most models of disruptive selection assume exploitative competition. We experimentally investigated whether the type of competition affects the outcome of competitive interactions using a system where disruptive selection is common: Mexican spadefoot toads (Spea multiplicata). Spea tadpoles develop into alternative resource-use phenotypes: carnivores, which consume fairy shrimp and other tadpoles, and omnivores, which feed on algae and detritus. Tadpoles intermediate in phenotype have low fitness when competition is intense, as they are outcompeted by the specialized tadpoles. Our experiments revealed that the presence of carnivores significantly decreased foraging behavior in intermediate tadpoles, and that intermediate tadpoles had significantly lower growth rates in interference competition treatments with carnivores but not with omnivores. Interference competition may therefore be important in driving disruptive selection. As carnivore tadpoles are also cannibalistic, the âfearâ effect may have a greater impact on intermediate tadpoles than exploitative competition alone, similarly to non-consumptive effects in predatorâprey or intraguild relationships
Ecology and biogeography of the endemic scorpion Euscorpius carpathicus (Scorpiones: Euscorpiidae): a multiscale analysis
Volume: 44Start Page: 88End Page: 9
Data from: Anthropogenic impact or anthropogenic accommodation? Distribution range expansion of the common wall lizard (Podarcis muralis) by means of artificial habitats in the north-eastern limits of its distribution range
During 2005-2008, field observations were made on the distribution and habitat occupation by Podarcis muralis in the middle Bistrita river basin. Prior to our study, this lizard was known from only 5 localities in Romanian Moldavia (Bicaz, Cheile Bicazului, Lacu RoĆu, Gherman and Dodeni). Through the present paper the authors acknowledge the existence of 28 sites populated by P. muralis in Moldavia and propose a new model for the range expansion of the species in the area using man-made structures such as road and railway fences and road beds, benefiting from the mild climate provided by the Izvorul Muntelui barrier lake and forming insular populations to further colonize suitable habitats
Data from: Anthropogenic impact or anthropogenic accommodation? Distribution range expansion of the common wall lizard (Podarcis muralis) by means of artificial habitats in the north-eastern limits of its distribution range
During 2005-2008, field observations were made on the distribution and habitat occupation by Podarcis muralis in the middle Bistrita river basin. Prior to our study, this lizard was known from only 5 localities in Romanian Moldavia (Bicaz, Cheile Bicazului, Lacu RoĆu, Gherman and Dodeni). Through the present paper the authors acknowledge the existence of 28 sites populated by P. muralis in Moldavia and propose a new model for the range expansion of the species in the area using man-made structures such as road and railway fences and road beds, benefiting from the mild climate provided by the Izvorul Muntelui barrier lake and forming insular populations to further colonize suitable habitats
An Updated Distribution of the Herpetofauna from the Natura 2000 Site RarÄu-GiumalÄu (Rosci0212), Romania
Amphibians and reptiles are among the most threatened animal species in Europe. Because of their legal conservation status, amphibians and reptiles may act as umbrella and flagship species in certain areas. The RarÄu-GiumalÄu Natura 2000 site (ROSCI 0212) is such an area that, despite its conservation status, is still exposed to human activities alterations. In addition, the standard data form of the site mentions only three amphibian species, which is notably below the herpetofauna diversity of the region. Therefore, the aim of this study is to update the existing knowledge on the local herpetofauna. To this end, herpetological field surveys were conducted in the area between Mayâ September, 2015, ten species being identified, as follows: six amphibians (Salamandra salamandra, Lissotriton montandoni, Ichthyosaura alpestris, Bombina variegata, Bufo bufo and Rana temporaria) and four reptiles (Anguis colchica, Lacerta agilis, Zootoca vivipara and Vipera berus). Species distribution is influenced by human activities, among which grazing seems to be the most important. The diversity of herpetofauna is not evenly distributed between the perimeters of the site. The GiumalÄu perimeter has only six species probably because of a lower habitat diversity compared to the RarÄu perimeter. Nine of the identified species are protected by European and national regulations, whereas the standard data form of the site lists only two of them, and one not confirmed by our study. Therefore, the standard data form, a tool for protective management, does not reflect the real situation of the herpetofauna of the site and for this reason, it should be updated
Updated distribution of hybrids between <em>Lissotriton vulgaris</em> and <em>Lissotriton montandoni</em> (Amphibia: Caudata: Salamandridae) in Romania
<em>Lissotriton montandoni</em> is an endemic newt species found only in the Carpathian Mountains and lives in sympatry with <em>Lissotriton vulgaris</em> in many aquatic habitats from the entire range of the former species in the Carpathian and Sudetes Mountains or in the hilly areas from the Subcarpathians. These two species usually generate hybrids where their parapatric ranges meet, especially along rivers that flow from the inside of the Carpathians, where valleys are used as ecological corridors by <em>L. vulgaris</em>. We surveyed several regions of the Eastern Carpathian Mountains between 2008 and 2011 and found 11 new populations of newts where hybrids between the two mentioned species were present. All new records of <em>L. montandoni</em> x <em>L. vulgaris</em> were described in the eastern part of the Eastern Carpathians, in NeamÈ County, a region known also from previous literature to be a âhot spotâ for hybrids between these two species. The present paper also presents an updated review of the distribution of <em>Lissotriton</em> hybrids in Romania
A revision of the distribution of sea kraits (Reptilia, Laticauda) with an updated occurrence dataset for ecological and conservation research
The genus Laticauda (Reptilia: Elapidae), commonly known as sea kraits, comprises eight species of marine amphibious snakes distributed along the shores of the Western Pacific Ocean and the Eastern Indian Ocean. We review the information available on the geographic range of sea kraits and analyze their distribution patterns. Generally, we found that south and south-west of Japan, Philippines Archipelago, parts of Indonesia, and Vanuatu have the highest diversity of sea krait species. Further, we compiled the information available on sea kraitsâ occurrences from a variety of sources, including museum records, field surveys, and the scientific literature. The final database comprises 694 occurrence records, with L. colubrina having the highest number of records and L. schistorhyncha the lowest. The occurrence records were georeferenced and compiled as a database for each sea krait species. This database can be freely used for future studies
Gherghel_et_al_Podarcis_muralis
Podarcis muralis distribution records used and discussed in the paper. The records are in shapefile format
Refining Climate Change Projections for Organisms with Low Dispersal Abilities: A Case Study of the Caspian Whip Snake
<div><p>Climate warming is one of the most important threats to biodiversity. Ectothermic organisms such as amphibians and reptiles are especially vulnerable as climatic conditions affect them directly. Ecological niche models (ENMs) are increasingly popular in ecological studies, but several drawbacks exist, including the limited ability to account for the dispersal potential of the species. In this study, we use ENMs to explore the impact of global climate change on the Caspian whip snake (<i>Dolichophis caspius</i>) as model for organisms with low dispersal abilities and to quantify dispersal to novel areas using GIS techniques. Models generated using Maxent 3.3.3 k and GARP for current distribution were projected on future climatic scenarios. A cost-distance analysis was run in ArcGIS 10 using geomorphological features, ecological conditions, and human footprint as âcostsâ to dispersal of the species to obtain a Maximum Dispersal Range (MDR) estimate. All models developed were statistically significant (<i>P</i><0.05) and recovered the currently known distribution of <i>D. caspius</i>. Models projected on future climatic conditions using Maxent predicted a doubling of suitable climatic area, while GARP predicted a more conservative expansion. Both models agreed on an expansion of suitable area northwards, with minor decreases at the southern distribution limit. The MDR area calculated using the Maxent model represented a third of the total area of the projected model. The MDR based on GARP models recovered only about 20% of the total area of the projected model. Thus, incorporating measures of speciesâ dispersal abilities greatly reduced estimated area of potential future distributions.</p></div