Male Reproductive Success and Multiple Paternity in Wild, Low-Density Populations of the Adder (Vipera berus)

We studied for the first time the occurrence of multiple paternity, male reproductive success, and neonate survival in wild, low-density adder (Vipera berus) populations using 13 microsatellite loci. Paternity was assigned for 15 clutches, collected during 3 years. Our data demonstrated that multiple paternity can occur at a high level (69%) in natural populations of V. berus, even if the density of adults is low. The high proportion of multiple sired clutches was comparable to the proportion observed in captive populations. Male reproductive success significantly increased with body length, and only the largest males successfully sired entire clutches. Finally, no relationship was detected between the number of fathers per clutch and neonate survival. These results suggest that multiple matings could be beneficial in populations with high level of inbreeding or low male fecundit

Limited genetic diversity and high differentiation among the remnant adder ( Viperaberus ) populations in the Swiss and French Jura Mountains

Although the adder (Viperaberus) has a large distribution area, this species is particularly threatened in Western Europe due to high habitat fragmentation and human persecution. We developed 13 new microsatellite markers in order to evaluate population structure and genetic diversity in the Swiss and French Jura Mountains, where the species is limited to only a few scattered populations. We found that V.berus exhibits a considerable genetic differentiation among populations (global FST=0.269), even if these are not geographically isolated. Moreover, the genetic diversity within populations in the Jura Mountains and in the less perturbed Swiss Alps is significantly lower than in other French populations, possibly due to post-glacial recolonisation processes. Finally, in order to minimize losses of genetic diversities within isolated populations, suggestions for the conservation of this species in fragmented habitats are propose

High population differentiation in the rock-dwelling land snail ( Trochulus caelatus ) endemic to the Swiss Jura Mountains

Understanding patterns of genetic structure is fundamental for developing successful management programmes for isolated populations of threatened species. Trochulus caelatus is a small terrestrial snail endemic to calcareous rock cliffs in the Northwestern Swiss Jura Mountains. Eight microsatellite loci were used to assess the effect of habitat isolation on genetic population structure and gene flow among nine populations occurring on distinct cliffs. We found a high genetic differentiation among populations (mean F ST=0.254) indicating that the populations are strongly isolated. Both allelic richness and effective population size were positively correlated with the size of the cliffs. Our findings support the hypothesis that T. caelatus survived on ice-free cliffs during the Pleistocene glacier advancements from the Alps. Due to the establishment of beech and pine forest under recent, temperate climate conditions, dispersal between cliffs is no longer possible for rock-dwelling snails such as T. caelatus. Our results provide basic data for developing a conservation action plan for this endangered gastropod specie

New polymorphic microsatellite markers of the endangered meadow viper ( Vipera ursinii ) identified by 454 high-throughput sequencing: when innovation meets conservation

The Next Generation Sequencing (pyrosequencing) technique allows rapid, low-cost development of microsatellite markers. We have used this technology to develop 14 polymorphic loci for the endangered meadow viper (Vipera ursinii). Based on 37,000 reads, we developed primers for 66 microsatellite loci and found that 14 were polymorphic. The number of alleles per locus varies from 1 to 12 (for 30 individuals tested). At a cost of about 1/3 that of a normal microsatellite development, we were able to define enough microsatellite markers to conduct population genetic studies on a non-model specie

Dorsal Pattern Variation and Sexual Dimorphism in Montivipera latifii (Mertens, Darevsky and Klemmer, 1967) (Ophidia: Viperidae)

In this study, sexual dimorphism and dorsal patterns were investigated in Latifi’s viper (Montivipera latifii) from Iran. Sexual dimorphism was evaluated in 13 males and 15 females using 12 morphological characteristics. Despite the low sample size, the results showed that both sexes significantly differ in the number of subcaudal scales, the number of outer circumocular scales and tail length. In a limited area, the Lar National Park, three different dorsal patterns were observed (n=26 specimens): about 50% displayed a complete zigzag dorsal pattern, 15% of the individuals displayed a striped dorsal pattern, and about 35% had an incomplete zigzag dorsal pattern. These findings confirmed partially results from former published studies. Finally, we hypothesised that the four pattern described in M. latifii could be a combination of only two genetically define dorsal marks.In this study, sexual dimorphism and dorsal patterns were investigated in Montivipera latifii. Sexual dimorphism in Latifi’s viper was evaluated in 13 males and 15 females using 12 morphological characteristics. The results showed that both sexes significantly differ in the number of subcaudal scales, the number of outer circumocular scales and tail length. In a limited area (Lar National Park, Iran), three different dorsal patterns were observed in M. latifii. Based on 26 observations, about 50% displayed a complete zigzag dorsal pattern, 15% of the individuals displayed a striped dorsal pattern and about 35% had an incomplete zigzag dorsal pattern. This result more or less confirmed former published results. Finally, we hypothesised that the four pattern described in M. latifii could be a combination on only two genetically define dorsal marks

Unravelling landscape variables with multiple approaches to overcome scarce species knowledge: a landscape genetic study of the slow worm

Landscape genetics was developed to detect landscape elements shaping genetic population structure, including the effects of fragmentation. Multifarious environmental variables can influence gene flow in different ways and expert knowledge is frequently used to construct friction maps. However, the extent of the migration and the movement of single individuals are frequently unknown, especially for non-model species, and friction maps only based on expert knowledge can be misleading. In this study, we used three different methods: isolation by distance (IBD), least-cost modelling and a strip-based approach to disentangle the human implication in the fragmentation process in the slow worm (Anguis fragilis), as well as the specific landscape elements shaping the genetic structure in a highly anthropized 16km2 area in Switzerland. Friction maps were constructed using expert opinion, but also based on the combination of all possible weightings for all landscape elements. The IBD indicated a significant effect of geographic distance on genetic differentiation. Further approaches demonstrated that highways and railways were the most important elements impeding the gene flow in this area. Surprisingly, we also found that agricultural areas and dense forests seemed to be used as dispersal corridors. These results confirmed that the slow worm has relatively unspecific habitat requirements. Finally, we showed that our models based on expert knowledge performed poorly compared to cautious analysis of each variable. This study demonstrated that landscape genetic analyses should take expert knowledge with caution and exhaustive analyses of each landscape element without a priori knowledge and different methods can be recommende

High Genetic Differentiation Among French Populations of the Orsini's Viper (Vipera ursinii ursinii) Based on Mitochondrial and Microsatellite Data: Implications for Conservation Management

The Orsini's viper (Vipera ursinii) is one of the most threatened snakes in Europe due to its highly fragmented distribution and specific open environment (steppic habitat) requirement. French populations are isolated on top of mountain massifs of the southern Prealps/Alps. Mitochondrial sequences (cytochrome b) and 6 microsatellite loci have been used to estimate the levels of genetic diversity and isolation within and among 11 French fragmented populations (a total of 157 individuals). Eleven cytochrome b haplotypes with a limited divergence were observed (mean divergence between haplotypes: 0.31%). However, we detected considerable genetic differentiation among populations (global FST = 0.76 and 0.26 for mitochondrial and nuclear DNA, respectively). Results indicate that 3 populations possibly went through a bottleneck and 1 population showed low genetic diversity compared with the others. Although a significant isolation by distance was detected for both markers, strong differentiation was also observed between geographically close populations, probably due to the ragged landscape that constitutes a serious barrier to gene flow owing to the limited dispersal capability of the viper. Despite some discrepancies between the 2 markers, 8 Management Units have been identified and should be considered for future management project

Low spatial autocorrelation in mountain biodiversity data and model residuals

Spatial autocorrelation (SAC) is a common feature of ecological data where observations tend to be more similar at some geographic distance(s) than expected by chance. Despite the implications of SAC for data dependencies, its impact on the performance of species distribution models (SDMs) remains controversial, with reports of both strong and negligible impacts on inference. Yet, no study has comprehensively assessed the prevalence and the strength of SAC in the residuals of SDMs over entire geographic areas. Here, we used a large-scale spatial inventory in the western Swiss Alps to provide a thorough assessment of the importance of SAC for (1) 850 species belonging to nine taxonomic groups, (2) six predictors commonly used for modeling species distributions, and (3) residuals obtained from SDMs fitted with two algorithms with the six predictors included as covariates. We used various statistical tools to evaluate (1) the global level of SAC, (2) the spatial pattern and spatial extent of SAC, and (3) whether local clusters of SAC can be detected. We further investigated the effect of the sampling design on SAC levels. Overall, while environmental predictors expectedly displayed high SAC levels, SAC in biodiversity data was rather low overall and vanished rapidly at a distance of similar to 5-10 km. We found low evidence for the existence of local clusters of SAC. Most importantly, model residuals were not spatially autocorrelated, suggesting that inferences derived from SDMs are unlikely to be affected by SAC. Further, our results suggest that the influence of SAC can be reduced by a careful sampling design. Overall, our results suggest that SAC is not a major concern for rugged mountain landscapes.Peer reviewe

Integrating ecosystem services within spatial biodiversity conservation prioritization in the Alps

As anthropogenic degradation of biodiversity and ecosystems increases, so does the potential threat to the supply of ecosystem services, a key contribution of nature to people. Biodiversity has often been used in spatial conservation planning and has been regarded as one among multiple services delivered by ecosystems. Hence, biodiversity conservation planning should be integrated in a framework of prioritizing services in order to inform decision-making. Here, we propose a prioritization approach based on scenarios maximising both the provision of ecosystem services and the conservation of biodiversity hotspots. Different weighting scenarios for the α-diversity in four taxonomic groups and 10 mapped ecosystem services were used to simulate varying priorities of policymakers in a mountain region. Our results illustrate how increasing priorities to ecosystem services can be disadvantageous to biodiversity. Moreover, the analysis to identify priority areas that best compromise the conservation of α-diversity and ecosystem services are predominantly not located within the current protected area network. Our analyses stress the need for an appropriate weighting of biodiversity within decision making that seek to integrate multiple ecosystem services. Our study paves the way toward further integration of multiple biodiversity groups and components, ecosystem services and various socio-economic scenarios, ultimately fuelling the development of more informed, evidence-based spatial planning decisions for conservation

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