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(A) Current mitochondrial Bayesian phylogenetic hypothesis of Vipera ursinii–renardi complex based on CYT B dataset of Ferchaud et al. (2012) and Zinenko et al. (2015); (B) Phylogenetic reconstruction of the concatenated dataset (mtDNA+nDNA genes) obtained in MrBayes/Maximum likelihood (see Table 1). Sequences of Vipera berus (Vbbe-HU, Vbbo-AL, Vbni-RO) included as outgroup are not shown. Bayesian posterior probabilities/bootstrap pseudoreplicates are shown at nodes; (C) SplitsTree phylogenetic network (Huson & Bryant 2006) of the dataset for five mitochondrial and nuclear loci sequenced in the present study using the neighbornet algorithm. Asterisks in Fig. 2C indicate both phased sequences in one branch. Numbers along the edges are the bootstrap support values from 1000 replicates. The scale bar indicates one substitution per one hundred nucleotide positions. Taxon names of the phylogenetic network correspond with the Table 1. Inset shows a male Greek Meadow Viper from Dhëmbel Mountains, Albania.
Source publication
Meadow vipers (Vipera ursinii–renardi complex) are small-bodied snakes that live in either lowland grasslands or mon-tane subalpine-alpine meadows spanning a distribution from France to western China. This complex has previously been the focus of several taxonomic studies which were based mainly on morphological, allozyme or immunological character...
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... reconstructions and allele networks. Phylogenetic analyses (BA, ML) and phylogenetic network (Fig. 2) constructed from the mitochondrial as well as from the concatenated dataset resulted in a topology concordant with main clades as observed in the mtDNA phylogeny of Ferchaud et al. (2012) and Zinenko et al. (2015) (Fig. 2). High Bayesian posterior probabilities (≥ 0.95; Fig. 2A, 2B) and bootstrap support values (> 70; Fig. 2A,B,C) ...
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... reconstructions and allele networks. Phylogenetic analyses (BA, ML) and phylogenetic network (Fig. 2) constructed from the mitochondrial as well as from the concatenated dataset resulted in a topology concordant with main clades as observed in the mtDNA phylogeny of Ferchaud et al. (2012) and Zinenko et al. (2015) (Fig. 2). High Bayesian posterior probabilities (≥ 0.95; Fig. 2A, 2B) and bootstrap support values (> 70; Fig. 2A,B,C) were noted for the graeca clade as well as for most of other included clades (Fig. 2). Concatenated mtDNA + nDNA data set revealed four deeply divergent clades within the ursinii-renardi complex, with a high degree of structure ...
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... networks. Phylogenetic analyses (BA, ML) and phylogenetic network (Fig. 2) constructed from the mitochondrial as well as from the concatenated dataset resulted in a topology concordant with main clades as observed in the mtDNA phylogeny of Ferchaud et al. (2012) and Zinenko et al. (2015) (Fig. 2). High Bayesian posterior probabilities (≥ 0.95; Fig. 2A, 2B) and bootstrap support values (> 70; Fig. 2A,B,C) were noted for the graeca clade as well as for most of other included clades (Fig. 2). Concatenated mtDNA + nDNA data set revealed four deeply divergent clades within the ursinii-renardi complex, with a high degree of structure corresponding to divergent lineages (see Fig. 2). There is ...
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... network (Fig. 2) constructed from the mitochondrial as well as from the concatenated dataset resulted in a topology concordant with main clades as observed in the mtDNA phylogeny of Ferchaud et al. (2012) and Zinenko et al. (2015) (Fig. 2). High Bayesian posterior probabilities (≥ 0.95; Fig. 2A, 2B) and bootstrap support values (> 70; Fig. 2A,B,C) were noted for the graeca clade as well as for most of other included clades (Fig. 2). Concatenated mtDNA + nDNA data set revealed four deeply divergent clades within the ursinii-renardi complex, with a high degree of structure corresponding to divergent lineages (see Fig. 2). There is strong support for the graeca clade and for ...
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... dataset resulted in a topology concordant with main clades as observed in the mtDNA phylogeny of Ferchaud et al. (2012) and Zinenko et al. (2015) (Fig. 2). High Bayesian posterior probabilities (≥ 0.95; Fig. 2A, 2B) and bootstrap support values (> 70; Fig. 2A,B,C) were noted for the graeca clade as well as for most of other included clades (Fig. 2). Concatenated mtDNA + nDNA data set revealed four deeply divergent clades within the ursinii-renardi complex, with a high degree of structure corresponding to divergent lineages (see Fig. 2). There is strong support for the graeca clade and for clade covering the V. u. moldavica, V. u. rakosiensis and V. u. macrops subclades. Similarly ...
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... (≥ 0.95; Fig. 2A, 2B) and bootstrap support values (> 70; Fig. 2A,B,C) were noted for the graeca clade as well as for most of other included clades (Fig. 2). Concatenated mtDNA + nDNA data set revealed four deeply divergent clades within the ursinii-renardi complex, with a high degree of structure corresponding to divergent lineages (see Fig. 2). There is strong support for the graeca clade and for clade covering the V. u. moldavica, V. u. rakosiensis and V. u. macrops subclades. Similarly to mtDNA tree, a clade covering V. u. ursinii and V. ursinii ssp. was not supported by BA analysis. The clade covering Vipera renardi-eriwanensis subclades is not supported in concatenated ...
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... manual ( Drummond et al. 2012b) indicating adequate mixing of the MCMC analyses. The ESS of the likelihoods was > 4000. The topology inferred from the maximum clade credibility species tree based on the mitochondrial and nuclear loci was the same as the mtDNA gene tree of Ferchaud et al. (2012), and similar to the topology Zinenko et al. (2015) (Fig. 2A). The graeca lineage is sister to all other members of the ursinii-renardi group, and V. renardi is the sister lineage to the ursinii group. Within the V. ursinii group, the montane vipers of V. u. ursinii and V. ursinii ssp. from Croatia form a clade sister to a lowland- montane clade of V. u. rakosiensis, V. u. moldavica and V. u. ...
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... Vipera berus (Vbbe-HU, Vbbo-AL, Vbni-RO) included as outgroup are not shown. Bayesian posterior probabilities/bootstrap pseudoreplicates are shown at nodes; (C) SplitsTree phylogenetic network (Huson & Bryant 2006) of the dataset for five mitochondrial and nuclear loci sequenced in the present study using the neighbornet algorithm. Asterisks in Fig. 2C . Species tree of the Vipera ursinii-renardi complex (with V. berus as outgroup) as inferred in *BEAST based on two mitochondrial and three nuclear loci (A); species-tree cloudogram of the complex based on 27 000 post-burn-in trees resulting from 3 runs of *BEAST, each producing 10,000 trees from which 10% was discarded as burn-in. ...
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... as burn-in. Higher colour densities represent higher levels of certainty. Maximum clade credibility tree is superimposed upon the cloudogram in bold violet (B). Values of posterior probabilities are given. This figure is published in colour in the online version, the colours of the branches correspond with the colour of mitochondrial lineages in Fig. ...
Citations
... On the one hand, species and subspecies show great external variability in the traits traditionally assessed in snake taxonomy (e.g., skull morphology, scalation, color patterns; Freitas et al., 2020), but which can be influenced by unsuspected hybridization or local selection alongside many extrinsic factors (e.g., Dubey et al., 2015;Martínez-Freiría et al., 2020b;Mebert et al., 2015Mebert et al., , 2017. On the other hand, phylogeographic analyses have essentially relied on mtDNA (e.g., Ursenbacher et al., 2006Ursenbacher et al., , 2008Martínez-Freiría et al., 2020a), together with a few conserved and thus weakly informative nuclear genes (e.g., Alencar et al., 2016;Mizsei et al., 2017;Doniol-Valcroze et al., 2021). While these markers presently offer the most comprehensive reference for species delimitation in the genus (reviewed by Freitas et al., 2020), to what extent the mitochondrial tree depicts the complete evolutionary history of Vipera is questionable, especially since many Viperidae species are known to hybridize despite strong molecular and phenotypic divergence (Guiller et al., 2017;Mochales-Riaño et al., 2023). ...
Despite decades of molecular research, phylogenetic relationships in Palearctic vipers (genus Vipera) still essentially rely on a few loci, such as mitochondrial barcoding genes. Here we examined the diversity and evolution of Vipera with ddRAD-seq data from 33 representative species and subspecies. Phylogenomic analyses of ∼ 1.1 Mb recovered nine major clades corresponding to known species/species complexes which are generally consistent with the mitochondrial phylogeny, albeit with a few deep discrepancies that highlight past hybridization events. The most spectacular case is the Italian-endemic V. walser, which is grouped with the alpine genetic diversity of V. berus in the nuclear tree despite carrying a divergent mitogenome related to the Caucasian V. kaznakovi complex. Clustering analyses of SNPs suggest potential admixture between diverged Iberian taxa (V. aspis zinnikeri and V. seoanei), and confirm that the Anatolian V. pontica corresponds to occasional hybrids between V. (ammodytes) meridionalis and V. kaznakovi. Finally, all analyzed lineages of the V. berus complex (including V. walser and V. barani) form vast areas of admixture and may be delimited as subspecies. Our study sets grounds for future taxonomic and phylogeographic surveys on Palearctic vipers, a group of prime interest for toxinological, ecological, biogeographic and conservation research.
... The nominal subspecies V. r. renardi sometimes referred to as 'western' or 'lowland' V. renardi (Nilson & Andr en, 2001;Zinenko et al., 2015) was involved in our study. V. ursinii (Bonaparte, 1835) is a vulnerable species endemic to Europe, consisting of three phylogenetically divergent lineages in sub-alpine meadows and two in lowland grasslands (Ferchaud et al., 2012;Mizsei et al., 2017). V. ursinii rakosiensis (M ehely, 1893), also known as the Hungarian meadow viper, an endangered lowland subspecies (P echy et al., 2015) was involved in our study. ...
... ursinii), while a basal lineage survived in the south Balkans (V. graeca) (Ferchaud et al., 2012;Freitas et al., 2020;Mizsei et al., 2017;Zinenko et al., 2015). ...
Understanding animals' selection of microhabitats is important in both ecology and biodiversity conservation. However, there is no generally accepted methodology for the characterization of microhabitats, especially for vegetation structure. We studied microhabitat selection of three Vipera snakes by comparing grassland vegetation structure between viper occurrence points and random points in three grassland ecosystems: V. graeca in mountain meadows of Albania, V. renardi in loess steppes of Ukraine and V. ursinii in sand grasslands in Hungary. We quantified vegetation structure in an objective manner by automated processing of images taken of the vegetation against a vegetation profile board under standardized conditions. We developed an R script for automatic calculation of four vegetation structure variables derived from raster data obtained in the images: leaf area (LA), height of closed vegetation (HCV), maximum height of vegetation (MHV) and foliage height diversity (FHD). Generalized linear mixed models revealed that snake occurrence was positively related to HCV in V. graeca, to LA in V. renardi and to LA and MHV in V. ursinii, and negatively to HCV in V. ursinii. Our results demonstrate that vegetation structure variables derived from automated image processing significantly relate to viper microhabitat selection. Our method minimizes the risk of subjectivity in measuring vegetation structure, enables the aggregation of adjacent pixel data and is suitable for comparison of or extrapolation across different vegetation types or ecosystems.
... It is a small-sized moderately venomous species belonging to the genus Gloydius of Central Asian origin that diverged about 2.5 million years ago (Asadi et al., 2019). Smaller insectivorous species of adders from the Vipera ursini-renardi complex (Mizsei et al., 2017) resemble other viper species, but due to their smaller size, they are much less venomous. They have a highly fragmented distribution, ranging from Eastern France to Western China (Nilson and Andrén, 2001). ...
Snakes are known as highly fear-evoking animals, eliciting preferential attention and fast detection in humans. We examined the human fear response to snakes in the context of both current and evolutionary experiences, conducting our research in the cradle of humankind, the Horn of Africa. This region is characterized by the frequent occurrence of various snake species, including deadly venomous viperids (adders) and elapids (cobras and mambas). We conducted experiments in Somaliland and compared the results with data from Czech respondents to address the still unresolved questions: To which extent is human fear of snakes affected by evolutionary or current experience and local culture? Can people of both nationalities recognize venomous snakes as a category, or are they only afraid of certain species that are most dangerous in a given area? Are respondents of both nationalities equally afraid of deadly snakes from both families (Viperidae, Elapidae)? We employed a well-established picture-sorting approach, consisting of 48 snake species belonging to four distinct groups. Our results revealed significant agreement among Somali as well as Czech respondents. We found a highly significant effect of the stimulus on perceived fear in both populations. Vipers appeared to be the most salient stimuli in both populations, as they occupied the highest positions according to the reported level of subjectively perceived fear. The position of vipers strongly contrasts with the fear ranking of deadly venomous elapids, which were in lower positions. Fear scores of vipers were significantly higher in both populations, and their best predictor was the body width of the snake. The evolutionary, cultural, and cognitive aspects of this phenomenon are discussed.
... The most closely related species with similar evolutionary background, the European ground squirrel (Spermophilus citellus) also originated from Asia Minor and colonised Europe through the Balkans (Gündüz et al.;Kajtoch et al. 2016;Ř íčanová et al. 2011). Such a 'Balkan' colonisation route of steppe animals are well-known in the literature, and the examples include the Balkan wall-lizard, Podarcis tauricus (Psonis et al. 2018), the European meadow-vipers, Vipera ursinii-renardi group (Mizsei et al. 2017), a geotrupid beetle Lethrus apterus (Tóth et al. 2019), the bronze glandular bush-cricket Bradyporus dasypus (Ivković et al. 2016), and the Russian marbled white, Melanargia russiae (Dincȃ et al. 2018), among others. In these cases, the Balkan high mountains act as refugial territories for relict species (e.g., Vipera graeca, Lethrus spp.), or relict lineages within species (e.g., Spermophilus citellus). ...
Species delimitation is a powerful approach to assist taxonomic decisions in challenging taxa where species boundaries are hard to establish. European taxa of the blind mole rats (genus Nannospalax) display small morphological differences and complex chromosomal evolution at a shallow evolutionary divergence level. Previous analyses led to the recognition of 25 ‘forms’ in their distribution area. We provide a comprehensive framework to improve knowledge on the evolutionary history and revise the taxonomy of European blind mole rats based on samples from all but three of the 25 forms. We sequenced two nuclear-encoded genetic regions and the whole mitochondrial cytochrome b gene for phylogenetic tree reconstructions using concatenation and coalescence-based species-tree estimations. The phylogenetic analyses confirmed that Aegean N. insularis belongs to N. superspecies xanthodon, and that it represents the second known species of this superspecies in Europe. Mainland taxa reached Europe from Asia Minor in two colonisation events corresponding to two superspecies-level taxa: N. superspecies monticola (taxon established herewith) reached Europe c. 2.1 million years ago (Mya) and was followed by N. superspecies leucodon (re-defined herewith) c. 1.5 Mya. Species delimitation allowed the clarification of the taxonomic contents of the above superspecies. N. superspecies monticola contains three species geographically confined to the western periphery of the distribution of blind mole rats, whereas N. superspecies leucodon is more speciose with six species and several additional subspecies. The observed geographic pattern hints at a robust peripatric speciation process and rapid chromosomal evolution. The present treatment is thus regarded as the minimum taxonomic content of each lineage, which can be further refined based on other sources of information such as karyological traits, crossbreeding experiments, etc. The species delimitation models also allowed the recognition of a hitherto unnamed blind mole rat taxon from Albania, described here as a new subspecies.
... The Acridophaga subgenus (hereafter referred to as grassland vipers), encompassing the Vipera ursinii complex, V. renardi complex, V. dinniki, V. graeca, V. walser, V. kaznakovi, V. darevskii complex, and V. anatolica, constitute numerous phylogenetically distinct species and subspecies. These are recognized as evolutionary significant units (ESUs) due to the distinct levels of divergence and evident allopatric speciation patterns (Nilson and Andrén 2001, Ferchaud et al. 2012, Zinenko et al. 2015, Mizsei et al. 2017, Freitas et al. 2020, Vörös et al. 2022. Grassland vipers occupy a wide range of the Palaearctic steppe biome at different elevations, but some taxa also inhabit humid alpine grasslands above the tree line in the Mediterranean and Central Asian mountain chains (Fig. 1). ...
... We validated the records based on the available information for each specimen (morphology) or the observation (photographs). In case of the lack of visual information, we checked the indicated location using satellite imagery and the expected distribution ranges estimated based on molecular data (Ferchaud et al. 2012, Zinenko et al. 2015, Mizsei et al. 2017, Freitas et al. 2020, Vörös et al. 2022. Dataset compilation and data validation resulted in N = 4266 occurrence coordinates. ...
The thermal tolerance of ectotherms is a critical factor that influences their distribution, physiology, behaviour, and, ultimately, survival. Understanding the factors that shape thermal tolerance in these organisms is, therefore, of great importance for predicting their responses to forecasted climate warming. Here, we investigated the voluntary thermal maximum (VTmax) of nine grassland viper taxa and explored the factors that influence this trait. The small size of these vipers and the open landscape they inhabit render them particularly vulnerable to overheating and dehydration. We found that the VTmax of grassland vipers is influenced by environmental temperature, precipitation, short-wave flux, and individual body size, rather than by phylogenetic relatedness. Vipers living in colder environments exhibited a higher VTmax, contradicting the hypothesis that environmental temperature is positively related to VTmax. Our findings emphasize the importance of considering local to regional adaptations and environmental conditions when studying thermal physiology and the evolution of thermal tolerance in ectotherms.
... Modern molecular data suggested that V. berus belongs to a separate clade diverged from the V. ursinii-renardi clade already in the Late Miocene time (Zinenko et al. 2015). During the Pliocene, approximately 3-4 Ma, the latter clade split further into the V. renardi and the V. ursinii clades, which subsequently dispersed north-west and north-east to form the present ranges (Ferchaud et al. 2012;Zinenko et al. 2015;Mizsei et al. 2017). ...
... within Vipera 1 and Vipera 2 clades) tend to occur in warmer and dryer habitats as compared with Balkans), and exhibit some phenotypic traits (e.g. small body size, ectotherm-based diet) typical of montane environments (Freitas et al., 2018;Mizsei et al., 2017). Similarly, V. monticola RIF shares climatic correlates comparable to lineages belonging to the Pelias clade. ...
Aim
Allopatric speciation is the primary mode of diversification in the Mediterranean Basin. However, the contribution of climatic adaptation during this process is contradictory. In this work, we investigate the eco-evolutionary processes that drove diversification in this region, using European vipers as a case study. We describe the climatic requirements of different lineages to compare their responses to the Pleistocene climatic oscillations and tackle the evolutionary mechanisms underlying their diversification.
Location
Eurasia and North Africa.
Taxon
European vipers (genus Vipera).
Methods
We used ecological niche modelling (ENM) to identify the climatic requirements of 24 Vipera lineages and infer past range dynamics associated with their diversification during the Pleistocene. To test whether climatic niches varied across lineages, we calculated the phylogenetic signal of different climatic variables and examined the relationship with phylogenetic relatedness. To investigate climatic niche evolution and test for phylogenetic niche conservatism (PNC), we quantified pairwise niche overlap in sister phylogenetic units under a 3D hypervolume approach.
Results
ENM identified temperature annual range, precipitation of wettest month and precipitation of driest quarter as the most important climatic variables related to the distribution of most lineages, validating Pelias clade as cold-adapted, and Vipera 1 and Vipera 2 as warm-adapted clades. Projections to past conditions varied among clades, with Pelias and Vipera 1 having more similar responses, while Vipera 2 exhibited greater variability. We found significant phylogenetic signal in one temperature-related and two humidity-related climatic variables and detected high complexity in ecological niche evolution across the phylogeny, both rejecting the hypothesis of PNC.
Main Conclusions
Climatic adaptation played a significant role in driving diversification among European vipers. Cold-adapted and warm-adapted lineages presented similar climatic requirements and remarkable responses to Pleistocene stages, resulting in an intricate pattern of niche divergence along the phylogeny that favours local adaptation rather than PNC.
... The southwestern Balkans is well known as a centre of endemism (e.g., Radea et al. 2017;Sfenthourakis and Hornung 2018;Allegrucci et al. 2021;Mermygkas et al. 2021) including amphibians and reptiles. Endemic species or unique evolutionary lineages are reported in salamanders (Recuero et al. 2014;Pabijan et al. 2017), toads (Fijarczyk et al. 2011;Dufresnes, Mazepa et al. 2019a), frogs (Dufresnes et al. 2013;Jablonski et al. 2021), lizards Psonis et al. 2017;Kiourtsoglou et al. 2021;Strachinis et al. 2021), or snakes (Guicking et al. 2009;Musilová et al. 2010;Mizsei et al. 2017;Jablonski et al. 2019). The southwestern Balkans is inhabited by three endemic water frog taxa of the genus Pelophylax. ...
The genus Pelophylax (water frogs) includes relatively common, widely distributed, and even invasive species, but also endemic taxa with small ranges and limited knowledge concerning their ecology and evolution. Among poorly studied species belong endemics of the southwestern Balkans, namely Pelophylax shqipericus, P. epeiroticus and P. kurtmuelleri. In this study, we focused on the genetic variability of these species aiming to reveal their phylogeographic patterns and Quaternary history. We used 1,088 published and newly obtained sequences of the mitochondrial ND2 gene and a variety of analyses, including molecular phylogenetics and dating, historical demography, and species distribution modeling (SDM). We revelated the existence of two mitochondrial lineages within P. epeiroticus and P. shqipericus that diverged at ~ 0.9 Mya and ~ 0.8 Mya, respectively. Contrarily, no deeply diverged lineages were found in P. kurtmuelleri. Pelophylax kurtmuelleri also shows a close phylogenetic relationship with widely distributed P. ridibundus, suggesting that both represent one evolutionary clade called here P. ridibundus/kurtmuelleri. The estimated split between both lineag-es in the clade P. ridibundus/kurtmuelleri date back to ~ 0.6 Mya. The divergence between the ridibundus and kurtmuelleri lineages on the ND2 gene is thus lower than the divergence between the two lineages found in P. epeiroticus and P. shqipericus. According to haplotype networks, demographic analyses, and SDM, endemic water frogs survived the last glacial maximum (LGM) in Balkan in the Balkans microrefugia, and their distribution has not changed significantly or even retracted since the LGM. Haplotypes of the kurtmuelleri lineage were also found in northern parts of Europe, where haplotype diversity is however much lower than in the Balkans, suggesting the possible hypothesis of their postglacial expansion to the north.
... Although the limits of mtDNA analyses are known for a long time (e.g., maternal inheritance, thus lack of detection of hybrids), the sequencing of several parts of this genome helped to identify evolutionary units formed in the course of dispersion and evolution. Further, if confirmed by other lines of evidence (e.g., morphological differences, indication of genetic isolation and divergence across nuclear genome) have led to taxonomic conclusions (Mizsei et al., 2017;Speybroeck et al., 2020). But this approach based on a single locus is more and more criticised to define taxa, as numerous discrepancies in the stories they tell (e.g., Ujvari et al., 2005;Edwards and Bensch, 2009). ...
... All demonstrated similar phylogenetic history, with a strong support for most subspecies previously described (V. u. ursinii in France and Italy; V. u. rakosiensis in Hungary and western Romania; V. u. moldavica in eastern Romania and Republic of Moldova; V. u. greaca in Greece and Albania -now recognised as a species [Mizsei et al., 2017]). However, these studies highlighted a polyphyletic position of V. u. macrops, with populations of northwestern Dinarides (Croatia and western part of Bosnia and Herzegovina) being more related to V. u. ursinii and populations from southeastern Dinarides (southeastern part of Bosnia and Herzegovina, Montenegro, Serbia, western part of Kosovo province) and Hellenides (eastern part of Kosovo province and North Macedonia) being more related to V. u. rakosiensis and V. u. moldavica (Ferchaud et al., 2012;Gvozdik et al., 2012;Zinenko et al., 2015). ...
... However, these studies highlighted a polyphyletic position of V. u. macrops, with populations of northwestern Dinarides (Croatia and western part of Bosnia and Herzegovina) being more related to V. u. ursinii and populations from southeastern Dinarides (southeastern part of Bosnia and Herzegovina, Montenegro, Serbia, western part of Kosovo province) and Hellenides (eastern part of Kosovo province and North Macedonia) being more related to V. u. rakosiensis and V. u. moldavica (Ferchaud et al., 2012;Gvozdik et al., 2012;Zinenko et al., 2015). However, a close inspection of the article of Mizsei et al. (2017) reveals that the nDNA of northwestern and southeastern populations of V. u. macrops are more similar compared to other V. ursinii subspecies, also suggesting some discrepancies between nDNA and mtDNA within V. ursinii. ...
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. rakosisensis 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.
... The nominal subspecies V. r. renardi , sometimes referred to as "western" or "lowland" V. renardi (Nilson & Andrén, 2001;Zinenko et al., 2015) was involved in our study. V. ursinii (Bonaparte, 1835) is a vulnerable species endemic to Europe, consisting of three phylogenetically divergent lineages in sub-alpine meadows and two on lowland grasslands (Ferchaud et al., 2012;Mizsei et al., 2017).V. ursinii rakosiensis (Méhely, 1893), also known as the Hungarian meadow viper, an endangered lowland subspecies (Péchy et al., 2015) was involved in our study. In each study system, we addressed the same three questions: (1) Which variables describing vegetation structure explain the occurrence of particular snake species? ...
1. Understanding animals’ selection of microhabitats is important in both ecology and biodiversity conservation. However, there is no generally accepted methodology for the characterisation of microhabitats, especially for vegetation structure. 2. Here we present a method that objectively characterises vegetation structure by using automated processing of images taken of the vegetation against a whiteboard under standardised conditions. We developed an R script for automatic calculation of four vegetation structure variables derived from raster data stored in the images: leaf area (LA), height of closed vegetation (HCV), maximum height of vegetation (MHC), and foliage height diversity (FHD). 3. We demonstrate the applicability of this method by testing the influence of vegetation structure on the occurrence of three viperid snakes in three grassland ecosystems: Vipera graeca in mountain meadows in Albania, V. renardi in loess steppes in Ukraine and V. ursinii in sand grasslands in Hungary. 4. We found that the variables followed normal distribution and there was minimal correlation between those. Generalized linear mixed models revealed that snake occurrence was positively related to HCV in V. graeca, to LA in V. renardi and to LA and MHC in V. ursinii, and negatively to FHD in V. renardi, and to HCV in V. ursinii. 5. Our results demonstrate that biologically meaningful vegetation structure variables can be derived from automated image processing. Our method minimises the risk of subjectivity in measuring vegetation structure, allows upscaling if neighbouring pixels are combined, and is suitable for comparison of or extrapolation across different grasslands, vegetation types or ecosystems.
