Landscape heterogeneity and fragmentation are key challenges for biodiversity conservation. As Earth's landscape is increasingly dominated by anthropogenic land use, it is clear that broad-scale ...systems of nature reserves connected by corridors are needed to enable the dispersal of flora and fauna. The European Union currently supports a continent-wide network of protected areas, the Natura 2000 program, but this program lacks the necessary connectivity component. To examine whether a comprehensive network could be built in order to protect amphibians and reptiles, two taxonomic groups sensitive to environmental changes due to their physiological constrains and low dispersal capacity, we used species' distribution maps, the sites of community interest (SCIs) in Romania, and landscape resistance rasters. Except Vipera ursinii rakosiensis, all amphibians and reptiles had corridors mapped that, when assembled, provided linkages for up to 27 species. Natura 2000 species were not good candidates for umbrella species as these linkages covered only 17% of the corridors for all species. Important Areas for Connectivity were identified in the Carpathian Mountains and along the Danube River, further confirming these regions as hot spots for biodiversity in Europe, where successful linkages are most likely. In the end, while such corridors may not be created just for amphibians and reptiles, they can easily be incorporated into more complex linkages with corridors for more charismatic species, therefore enhancing the corridors' value in terms of quality and structure.
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 (
).
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 'fear' effect may have a greater impact on intermediate tadpoles than exploitative competition alone, similarly to non-consumptive effects in predator-prey or intraguild relationships.
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 (Dolichophis caspius) 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 "costs" to dispersal of the species to obtain a Maximum Dispersal Range (MDR) estimate. All models developed were statistically significant (P<0.05) and recovered the currently known distribution of D. caspius. 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 species' dispersal abilities greatly reduced estimated area of potential future distributions.
Activity patterns in animals are often species-specific, and can be generally categorized as diurnal, crepuscular, or nocturnal. Understanding these patterns provides insight into ecological ...adaptations and behaviors. The common grass snake (
), one of the most common and widespread European snake species, is traditionally considered diurnal, with scarce evidence of its crepuscular and nocturnal activity. We aimed to document the distribution, environmental conditions, and potential phenotype associations of nighttime activity in
. We used citizen science data from iNaturalist (1992-2022), Observation.org (2012-2022), together with personal field observations (2010-2023) to collect 127 crepuscular and nocturnal activity records. Most observations occurred between May and August, coinciding with the peak activity period of grass snakes across their distribution range. Statistical analyses revealed no significant difference in mean daily temperatures between crepuscular and nocturnal observations. However, striped individuals displayed nocturnal activity at higher temperatures, consistent with their distribution in warmer regions, but failed to register any difference when tested on a geographic subsample, that accounted for sympatry of the phenotypes. Surprisingly, we found no significant impact of moon presence or moonlight on nighttime activity or age class, contrary to expectations based on other snake species' responses. While our study reveals that nocturnal activity in the common grass snake is geographically widespread, further research is warranted to understand its drivers and ecological implications. This study highlights the value of citizen science platforms for biological and ecological research, offering unparalleled spatial and temporal coverage by their users. In conclusion, our work extends the knowledge of nocturnal behavior in
and underlines the critical role of citizen science in discovering behavioral aspects of common and widespread species.
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 Roşu, 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.
Lissotriton montandoni is an endemic newt species found only in the Carpathian Mountains and lives in sympatry with Lissotriton vulgaris 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 L. vulgaris. 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 L. montandoni x L. vulgaris were described in the eastern part of the Eastern Carpathians, in Neamț County, a region known also from previous literature to be a ‘hot spot’ for hybrids between these two species. The present paper also presents an updated review of the distribution of Lissotriton hybrids in Romania.
Understanding how climate and land cover currently shape species distributions and community structure is crucial to inform conservation decisions. Unfortunately, limited information is available for ...the relative importance of climatic and land use variables in determining the distribution of amphibians and reptiles. Here, we studied amphibian and reptile communities from the Carpathian Mountains, asking (i) to what extent is the distribution of reptiles and amphibians determined by environmental gradients, (ii) does the response to these factors differ between amphibians and reptiles, and (iii) are reptile and amphibian communities at higher altitudes more similar to each other than communities from lower altitudes. We found that forests, pastures, and heterogeneous arable land best explain the composition of the herpetofauna, with mountain communities associated with coniferous forests, and lowland species with mixed or broad-leaved forests and pastures. Our results also suggest that reptiles and amphibians respond idiosyncratically to the influence of climate and land use. Reptiles responded more to land use and less to climate variables compared with amphibians. Of the three amphibian hybrids registered, one (
Bombina
) was associated with heterogeneous arable land. These results have potential implications for future conservation planning, especially in the light of global climate change and changes in land use. Hence, local and regional processes are important in shaping amphibian and reptile communities.
Abstract
The designation of taxonomic units has important implications for the understanding and conservation of biodiversity. Eurasian vipers are a monophyletic group of viperid snakes (Serpentes, ...Viperinae), currently comprising four genera (Daboia, Macrovipera, Montivipera and Vipera) and up to 40 species. Taxonomic units have been described using a wide variety of methods and criteria, and consequently, considerable controversy still surrounds the validity of some currently listed species. In order to promote a consensus- and evidence-based taxonomy of Eurasian vipers, we analysed published mitochondrial and nuclear DNA sequences for this group to reconstruct phylogenetic relationships among currently recognized 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 and identifies several instances of non-monophyly in described species. Nuclear DNA sequences show extremely low levels of genetic variation, with a widespread pattern of allele sharing among distant species, and even among genera. Revision of morphological data shows that most species designations rely on scalation traits that overlap extensively among species of the same genus. Based on our combined assessment, we recognize 15 taxa as valid species, three taxa which likely represent species complexes, 17 taxa of doubtful validity as species, and five taxa for which species status is maintained but further research is highly recommended to assess taxonomic arrangements. We stress the need to implement integrative taxonomic approaches for the recognition of evidence-based taxonomic units in Eurasian vipers.
Abstract
The Meadow and Steppe viper, Vipera ursinii-renardi complex is a well-studied group that is divided into several morphological subspecies. In this study, we combine the analyses of two ...mitochondrial genes with 9 microsatellite markers to compare both phylogenetic signals. Whereas the signal is similar between both genomes within most subspecies, the relative relationships between subspecies are more differentiated. Moreover, the nuclear phylogenetic reconstruction supports genetic homogeneity within V. u. macrops (in contrast to mtDNA). Both genetic portions show an unexpected differentiation between a population from Bistra Mountain and other V. u. macrops populations. Globally, the microsatellite markers suggest high genetic diversity in most subspecies, even in V. u. rakosiensis which is highly threatened; only V. u. macrops showed a limited genetic diversity. Within lowland subspecies, the differentiation between populations is globally limited compared to the distance between them (except in some populations of V. u. moldavica). The limited differentiation might be the consequence of a recent isolation (few decades) of previously large populations. Nevertheless, the only way to maintain this genetic diversity and to avoid an increase in genetic differentiation between populations in the future is to recreate suitable habitats and reconnect the populations.
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