We studied the thermal biology of the meadow lizard (Darevskia praticola) in the peripheral part of its distribution range (westernmost edge of the distribution area). We assessed whether these lizards actively thermoregulate, estimated the accuracy and effectiveness of thermoregulation, and evaluated the thermal quality of the habitat using the standard thermal parameters: body (), preferred () with set-point range () and operative temperatures (). of the meadow lizard under controlled laboratory conditions was between 27.8°C and 31.4°C. In the field and averaged 29.0°C and 26.1°C, respectively. A large proportion of s fell below the range of the meadow lizard, and lizard s were substantially closer to the species’ range. Obtained values of thermoregulatory indices suggested that the meadow lizard thermoregulated actively, with a rather high accuracy () and effectiveness ( and ), and that their habitat at this locality was thermally favourable during the spring. Our results suggest that thermal requirements of the meadow lizard resemble those of alpine lacertids, while their s and are lower than in most lacertid lizards. Further thermoregulation studies could be an important step in predicting the impact of the global climate change on the meadow lizard and the risks of local extinctions of its peripheral populations.
We examined degree of between-sides difference in number of femoral pores (fluctuating asymmetry, FA) in Podarcis muralis populations, distributed on islands and in coastal area of Lake Skadar (Southern Montenegro). The aim of this study was to test sensitivity of fluctuating asymmetry of chosen trait to isolation effect in the absence of anthropogenic impacts. The results indicate that FA in the number of femoral pores do not vary significantly between insular populations of P. muralis. Generally, there is negative but non-significant correlation between island size and FA level. Also, overdominance hypothesis of enhanced developmental homeostasis at higher levels of heterozygosity was not confirmed in this study. The results support earlier conclusions obtained from electrophoretic studies, that analyzed insular populations from Lake Skadar archipelago still do not suffer deleterious effects as a result of isolation.
Activity patterns of the sand viper, Vipera ammodytes from the central Balkans (Serbia, Montenegro and Former Yugoslav Republic of Macedonia) were analysed. The total sample (n = 118) was divided into adult males and females, and depending on the part of the day, habitat type, exposition, and behaviour in two separate seasons (spring and summer). Simple correspondence analysis showed that in spring, males and females were associated with different expositions, while in summer, they displayed different behaviours. Multivariate correspondence analysis showed that in spring males were found more often while basking during the midday in the open forests at south-western exposition. In summer, females were found more often while basking or hiding in the morning in rocky terrains at eastern and southern expositions. The results point out that seasonal variation and intergender differences in behaviour and microhabitat use may occur in sand vipers, as was previously observed in other viper species.
Theoretical and empirical studies revealed that fast evolving microsatellite markers might be successfully employed in phylogenetic reconstruction. In this study we used seven highly polymorphic microsatellite loci and six different genetic distances to infer the performance of microsatellites in estimation of phylogenetic relationships between closely related crested newt species (Triturus cristatus superspecies). Many intraspecific distances exceeded interspecific values likely due to loss of genetic distance linearity in time, revealing that none of them was able to estimate divergence between the species. The Neighbor-joining trees constructed on the basis of genetic distances showed trichotomies (three-way polychotomies) and low bootstrap support at the species level. This study thus revealed limits of microsatellites to estimate phylogenetic relationships between the crested newt taxa.
We investigated the relation between righting time (RT) and carapace morphology in 303 adult Hermann’s tortoises (Testudo hermanni Gmelin, 1789) from two geographically close localities. Their size, shape and body mass, adjusted for size, were significantly different between males and females. Righting time differed among the populations and was related to the ambient temperature and the relative body mass and carapace shape. However, analysis showed that the impact of carapace “form” (shape plus relative body mass) alone had only moderate influence on the variation in righting time (“function”). Both “form” and “function” did not contribute much to the segregation of individuals in geometric space, based on either sex or locality. An interesting detail was that tortoises with a height/width ratio of the shell contour higher than 0.75 had quite a short righting time (less than 100 seconds), which is in accordance with the proposed theoretical model of energy balance of righting in chelonians. We suppose that interactions between general carapace “form”, specific components of shell structure, physiological parameters and local environments shape variation in righting response in this species. An interdisciplinary approach combining geometric modeling with traditional biological disciplines would be needed to support this hypothesis.
In Squamates, head meristic characters are commonly used in analyses of intraspecific variability, systematics and phylogeny. Taxonomic significance of head scales is based on the assumption that discrete values of particular scales are set at birth and stable during individual ontogeny. In this paper, we analysed ontogenic changes of head scalation in a population of meadow viper (Vipera ursinii), based on multiple recaptures of marked individuals. Our results show that changes of cephalic scales occur both in immatures and in adults; the frequency of occurrence of change in the sample of re-photographed individuals was 52.2%. Oligomerisation was the most frequent change, found in 39.1% of re-photographed individuals. Changes in shape of cephalic plates as well as polymerisation were recorded in 30.4% of re-photographed individuals. Results of the log-linear analyses indicated no relation either between scale change and sex or between scale change and growth. Although we do not suggest that meristic characters of head scales are completely inadequate for taxonomic use, we point out the need for taking into account the ontogenic trajectories of these characters when analysing intra- and interpopulation variability, in systematics and phylogeny.
Macro- and microhabitat preference of Testudo hermanni boettgeri, the eastern subspecies of Hermann’s tortoise, was investigated utilizing modified methodology for the western subspecies which emphasized the importance of habitat heterogeneity preservation. The study objective was to explore the habitat preferences of the eastern subspecies of T. hermanni. Research was conducted within the same year at four localities in Eastern and Southeastern Serbia. Macrohabitat determination was conducted using a 0 to 5 land cover score system (coverage with herbaceous, bushy or tree vegetation) for 4 m2 tortoise encounter surroundings. Microhabitat analysis was carried out by determining the plant species in closest contact with the tortoise in the moment of recording. Plants were classified into six groups: 1) aromatic, 2) bramble, 3) herbaceous, 4) thorny shrub, 5) tree and 6) non-thorny shrubs. test was used for comparison between expected and empirical habitat preference. Results confirmed that the most attractive macrohabitats for Eastern Hermann’s tortoises in this part of the Balkans are meadows and open shrublands, with the addition of dense forest (important in wormer months), what is concordant with earlier data from the Mediterranean part of former Yugoslavia. The most attractive microhabitats were “herbaceous plants”, followed by “bramble”.
Skin lesions frequently present in adult lizards may be due to a variety of causes, both physical and infectious, including excessively high humidity and environmental temperature, malnutrition, concurrent disease etc. On the other hand, skin lesions in lizards could be simple evidence of various behavioural patterns and biotic interactions. However, studies on frequencies of dermal lesions and their anatomical and environmental correlates in lacertid lizards are rare. Here, we use Podarcis muralis to analyse the relations between occurrence of ectodermal lesions and three possible indicators of environmental stress (body condition index – BCI, infestation by ticks and tail condition) by evaluating differences among local populations at uni- and multivariate level. Our results showed that BCI, together with body size and sexual size dimorphism, varied between populations but had no direct influence on the presence of lesions. Males had higher frequencies of lesions and ticks but lower frequencies of broken tails than females. All three parameters varied between sites likely due to differences in predation/parasite exposures and agonistic interactions with conspecifics between sexes and populations. Results of multivariate analyses suggested that the occurrence of lesions is decoupled from the other morphological stress indicators. Detected associations indicated that relations between presence of lesions and other analysed variables are rather complex. Directions for further research on ectodermal lesions in lacertid lizards are provided.
We conducted a comparative (2D landmark-based geometric and traditional) morphometric analysis on tadpoles at early developmental stages. Two species of brown frog (Rana dalmatina and R. temporaria) and the common toad (Bufo bufo) were involved, all raised in the laboratory from fertilized eggs collected in their natural habitat. Taxonomic identification was confirmed by the DNA barcoding method with the 16S rRNA sequence as the gene marker. Interested to compare the methodologies for quantification and description of morphological differences among tadpoles of mentioned species, we aimed to: 1) calculate interspecies genetic distances as the most relevant measurement for species differentiation, 2) determine and describe size and shape variation, 3) identify relationships among the analyzed species at the morphological level and 4) assess their classification accuracy. Within the framework of the specified aims, both methodologies produced very similar results, i.e., the smallest divergence was between R. dalmatina and R. temporaria, while the most discriminative were B. bufo and R. temporaria. However, we observed subtle shape variation of the distal region of the tail that was detected only by the geometric morphometrics. Our findings support the following. Geometric morphometric method captures more subtle shape differences that were unable to be recovered from linear measurements. It performs slightly better in classification rate. Although it was not quantified, it stands to reason that there is no difference in time investment between the two approaches. Geometric morphometrics provides more information that can be leveraged to answer further questions and it has a clear advantage in visualizing.
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.