Smooth Snake Coronella Austriaca Research Articles

Predation by a smooth snake Coronella austriaca of an aspic viper Vipera aspis in Spain

Predation by a smooth snake Coronella austriaca of an aspic viper Vipera aspis in Spain

Developmental anomalies in the smooth snake, Coronella austriaca Laurenti, 1768 (Squamata, Colubridae) from Poland

We present four cases of rare developmental anomalies in the smooth snake Coronella austriaca Laurenti, 1768 from western Poland. These include brachycephaly, lordosis, a supernumerary row of ‘ventral’ scales, and the third reported case of dicephalism in snakes from Poland. All the cases are supported by X-ray radiography. One of the possible explanations for these anomalies is a low genetic variation in populations from western Poland.

Evolutionary divergence of the smooth snake (Serpentes, Colubridae): The role of the Balkans and Anatolia

AbstractThe smooth snake Coronella austriaca (Laurenti, 1768) is distributed across the western Palearctic throughout north‐central, southern Europe and western Asia. So far, only few phylogenetic studies, based on mitochondrial DNA, have been carried out on this species focusing mainly on the Iberian Peninsula and northern Europe, leaving unstudied some of important areas of its distribution. This study aims to cover this gap and to explore the phylogenetic relationships between the populations of in the Eastern Mediterranean and to detect possible historical refugia. With this objective, total genomic DNA was extracted from samples originated from the Balkans, Anatolia and a large part of Europe. Two mitochondrial (cyt b, 16S) and six nuclear (BDNF, NKTR, RAG1, RAG2, MC1R and PRLR) markers were combined for phylogenetic and chronophylogenetic analyses. The different analyses confirmed previous phylogeographic hypothesis showing the presence of several well‐supported clades distributed in Anatolia, Central Europe, Eastern Europe, Western Europe, the Balkans and the Iberian Peninsula and cryptic diversity within Anatolia and the Balkans. Moreover, dating analysis confirmed the diversification of the species during the Pleistocene, as well as the role of the Southern Balkans and Anatolia region as refugia during this period.

Conservation genetics of a wide-ranged temperate snake: same species, different locations, and different behaviour

Even though reptiles are threatened worldwide, few studies address their conservation, especially snakes. The goal of our study was to measure the genetic structure of a widely distributed temperate reptile, the smooth snake Coronella austriaca using microsatellite markers in two different areas at the core (Alsace, north-eastern France) and at the edge (Wallonia, southern Belgium) of its range. We sampled 506 individuals in 38 localities (respectively 10 and 28). Analysis of genetic structure conducted with a clustering method detected three clusters in Alsace, one group gathering all populations but two. In Wallonia, differentiation was observed on both sides of the Meuse River and in the Southern Ardenne region (southernmost sampling sites). Spatial autocorrelation analysis showed that statisticaly more related individuals occur together up to a distance of 2.8 km in Alsace and up to 10 km in Wallonia. Isolation by distance was detected in Wallonia but the distance explained a very limited part of the differentiation (r = 0.033), whereas no isolation-by-distance pattern was detected in Alsace. Even though genetic differentiation between populations separated by large rivers, highways, or crop fields was detected, dispersal between populations seem currently sufficient to avoid any kind of genetic drift in both regions. These results are similar to a previous study conducted in Poland, but strongly contrast with another analysis held in England which detected a sharp genetic structuring among populations that are geographically close. We consequently suggest that discrepancies could be related to the ecology of island populations and smaller densities.

Oophagy in the Smooth snake Coronella austriaca – first photographic record of bird egg predation

Oophagy in the Smooth snake Coronella austriaca – first photographic record of bird egg predation

Sex chromosome diversification in the smooth snake Coronella austriaca (Reptilia, Serpentes)

The smooth snake Coronella austriaca is a widespread Palearctic colubrid species. The species has been the subject of several molecular and phylogeographic studies which highlighted the occurrence of distinct genetic lineages in different areas of the species distribution, but scarce cytogenetic data are currently available on the species. In this paper we present a molecular and karyological study performed with several banding, staining methods and NOR-FISH on samples of C. austriaca from different geographical areas (Italy and Greece) of the species distribution. The molecular and phylogenetic analysis unambiguously placed the studied samples in different clades with a clear geographical pattern. The karyotype of the two female samples studied was composed of 2n = 36 chromosomes with 16 macro- and 20 microchromosomes and a mix of plesiomorphic and derivate chromosome features. All macrochromosomes were biarmed with the exception of pair 5 that was telocentric. NORs were detected on a microchromosome pair. In both females, the pair 4 was heteromorphic (and completely heterochromatic after C-banding in the Italian female), representing the first report of a ZZ/ZW sex chromosome system with female heterogamety in C. austriaca. In addition, the W chromosome showed a different morphology between the two female studied (submetacentric and subtelocentric), highlighting the occurrence of a chromosomal diversification among distinct geographical areas of the species distribution and further supporting that the species contains different diverging evolutionary clades.

Detectability of Elusive Reptiles under Artificial Cover Objects is Species- and Year-Specific

Field surveys of rare and elusive reptiles often encounter the problem of low detectability. Therefore, several techniques have been invented to improve detection probability and artificial cover objects (ACOs) are among the most commonly used in reptile studies. However, the methodological effectiveness of ACOs has been rarely evaluated and focused mostly on spatial aspects. The temporal dimension of the ACOs effectiveness remains still understudied, despite well-known seasonal variation in reptile activity patterns. Here, we examined seasonal and between-year variation in the fraction of occupied ACOs, as a proxy for detectability, in two elusive reptile species, the slow worm Anguis fragilis and smooth snake Coronella austriaca. We found that the use of ACOs was species-specific and showed high temporal variation. In the case of smooth snakes, monthly usage varied between years; specifically within-year variation of the proportion in occupied ACOs was most pronounced in 2015, but seems vanishing in consecutive years. This loss of of seasonal pattern occurs only in the last year of survey in the case of slow worm and monthly use of ACOs seem not to vary between years. Considerably low detectability of the studied species by the ACO method in some years may not necessarily indicate their low population density, but rather results from shifts in their diurnal activity and/or microhabitat use dependent on ambient temperatures. Increasing between-year variation in weather conditions may reduce repeatability of seasonal patterns of ACO usage, making we suggest additional detection techniques that could bee incorporated.

Reproduction probabilities and size distributions of the smooth snake Coronella austriaca in the Netherlands and Norway

Abstract Whether females participate in reproduction every year or rather skip years is pivotal information for understanding the dynamics of animal populations. In ectotherms this reproduction frequency might depend on factors like temperature, individual size, and prey availability. Here we studied the reproduction rate of the smooth snake Coronella austriaca at two latitudes: in Norway and The Netherlands. Reproductive and morphological data were collected in Norway (34 years) and The Netherlands (5 years). To account for differential resighting probabilities of pregnant and non-pregnant females, we performed multi-state mark-recapture analyses. Reproductive rate, quantified as the probability of participating in reproduction in consecutive years, was calculated for both pregnant and non-pregnant females. The results showed a clear difference in reproductive rate between the two latitudes, with only 15% of pregnant females reproducing again in the following year in Norway versus 93% in The Netherlands. Furthermore, in Norway females grew larger and started reproduction at a higher age. Litter size and juvenile total length and body mass were also significantly higher in Norwegian smooth snakes.

Age-Dependent Utilization of Shelters and Habitat in Two Reptile Species with Contrasting Intraspecific Interactions.

Simple SummaryIntraspecific interactions are known to affect habitat use in birds and mammals but their role in spatial ecology of reptiles is far less recognized. Our comparative study shows that species known to exhibit intraspecific predation (smooth snake Coronella austriaca) express clearly different patterns of habitat and shelter occupancy than a species with no such cannibalistic behavior (slow worm Anguis fragilis). Specifically, juvenile smooth snakes prefer sites and shelters not occupied by the adults, even despite suboptimal habitat conditions. We propose that such division indicates an avoidance of predation pressure set by larger individuals on the younger and smaller ones. On the contrary, in slow worms no tendency for intraspecific avoidance are observed, since specimens of different ages commonly share the same area and shelters. This points to higher flexibility in habitat use in slow worms, while the smooth snake population is spatially structured, with juveniles dispersed to the margins of the population range. For endangered smooth snakes, habitat conservation should therefore include a wide buffer zone to maintain the youngest fraction of the population. Future studies on habitat utilization in squamates needs to pay more attention to the social cues, a commonly overlooked aspect in the spatial ecology of reptiles.Reptiles undergo worldwide decline driven mostly by habitat change. Detailed recognition of factors underlying spatial structure and habitat utilization is therefore a prerequisite of effective conservation of this group. While the body of data on spatial ecology of reptiles is rapidly growing, studies on social factors remain still underrepresented. We studied age-specific patterns of shelter use, range size, and habitat preferences in the context of intraspecific interactions in the smooth snake Coronella austriaca—known to exhibit intraspecific predation—and the limbless lizard slow worm Anguis fragilis—with no such behavior observed. Despite smaller availability of preferred microhabitats, juveniles of smooth snakes occupied habitat and shelters located at the edge of the population range that did not overlap with adults. No such pattern was observed in the slow worm. Our study indicates that intraspecific interactions affect the spatial ecology of squamates. Passive and active protection of habitat must include wide buffers to preserve the poorly detectable young fraction of the population.

The role of managed coniferous forest in the conservation of reptiles

Commercially managed coniferous forest is often considered detrimental to wildlife despite their early developmental growth stages being well utilised by some species from a number of different taxa. Our study investigated the use of different aged conifer plantations by reptiles in southern England using arrays of artificial refuges, placed within 20 plantations of varying age, to determine the presence of reptiles annually within each between 2009 and 2013. All six native British reptile species (adder Vipera berus, grass snake Natrix natrix, smooth snake Coronella austriaca, common lizard Zootoca vivipara, sand lizard Lacerta agilis, slow worm Anguis fragilis) occurred in conifer plantations. Excluding the slow worm, which occurred in plantations of all ages, the majority of reptile observations occurred in plantations up to 20years old and where tree canopy cover was below 65% with the highest numbers occurring in 3–12year old plantations with a canopy cover below 50%. The early stages of plantation growth are utilised well by reptiles but become increasingly unsuitable over time. Furthermore, the availability of suitable reptile habitat is transient, depending on the rate of tree growth, the timing and extent of tree thinning and felling operations, the size of the plantation units and their proximity to adjacent areas inhabited by reptiles.Our study shows that coniferous forests can be managed so that both timber production and biodiversity conservation can be achieved through the formation of a mosaic of relatively small, multi-aged plantations and that small changes in ground preparation and habitat management practices may further enhance its suitability for reptiles and, by implication, for species from other taxa. The results of our study also have pertinence for species conservation and biodiversity within similar managed forestry throughout the world.

Lessons from a complex biogeographical scenario: morphological characters match mitochondrial lineages within Iberian Coronella austriaca (Reptilia: Colubridae)

Molecular evidence suggests that climatic fluctuations in the peninsulas of southern European during the Miocene and Pleistocene resulted in considerable genetic differentiation of organisms, probably following a 'refugia within refugia' model. We examined morphometric and meristic characters in museum specimens from the three Iberian clades of the smooth snake Coronella austriaca, previously described by molecular markers. We found sexual and interclade differences in scale counts and head shape. Sexes were dimorphic in the number of ventral and subcaudal scales, although sexual disparities in scale counts differed among clades. Moreover, discriminant and canonical analyses showed higher interclade differences in males than in females. The results obtained in the present study match those from molecular markers and confirm the population structure identified within Iberian C. austriaca. The observed sex discrepancy in this pattern suggests that males and females are subjected to different selective pressures along their Iberian distribution. In light of the above, C. austriaca may offer a useful model system in which to explore phylogeographical patterns in southern Europe, as well as the conflicts between processes driving morphological sexual divergence. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 210-223.

Distribution of amphibians and reptiles in central Poland: 1980-2000

Based on 3047 records from 97 recorders distribution maps were drawn for the amphibians and reptiles of central Poland (lirom 51°00’N to 52°15’N and from 18°20’E to 20°20’E). The study area was divided into 180 atlas fields based on the geographic grid. All data were gathered in 1980-2000, most of them (67%) however, in 1995-2000. 13 taxa of amphibians were found in 143 atlas fields and 6 species of reptiles were found in 121 atlas fields. The amphibians were (given with the number of atlas fields with the species found): 119 - Common frog Rana temporaria Linnaeus, 1758; 114 - Common toad Bufo bufo (Linnaeus, 1758); 97 - Moor frog Rana arvalis Nilsson, 1842; 94 - Fire-bellied toad Bomhina bombina (Linnaeus, 1761); 93 - Pool frog Rana lessonae Camerano, 1882; 87 - Tree frog Hyla arhorea (Linnaeus, 1758); 85 - Green toad Bufo viriiüs Laurenti, 1768; 72 - Smooth newt Triturus vulgaris (Linnaeus, 1758); 70 - Spadefoot Pelobales fuscus (Laurenti, 1768); 69 - Edible frog Rana kl. esculenia Linnaeus, 1758; 39 - Great crested newt Triturus cristatus (Laurenti, 1768); 30 - Marsh frog Rana ridibunda Pallas, 1771 and 28 - the Natterjack Bufo calamita Laurenti, 1768. The reptile species (given with the number o f atlas fields) were: 94 - Sand lizard Lacerta agilis Linnaeus, 1758; 72 - Slow-worm Anguis fragilis Linnaeus, 1758; 67 - Common lizard Lacerta vivipara Jacquin, 1787; 60 - Grass snake Natrix natrix (Linnaeus, 1758), 57 - Adder Vipera berus (Linnaeus, 1758) and 4 - the Smooth snake Coronella austriaca Laurenti, 1768. Six adult specimens of the European pond terrapin Emys orbicularis (Linnaeus) were also found, but breeding of this species in the area studied was not confirmed.

Chemoreceptive and behavioural responses of the common lizard Lacerta vivipara to snake chemical deposits

Behavioural cues were used to assay the capacity of common lizards to detect chemical deposits of snakes. The lizards were observed in cages that had been previously inhabited either by one of two species of snake that feed on lizards (the viper Vipera berus and the smooth snake Coronella austriaca), or the grass snake ( Natrix natrix), which does not feed on lizards. As a control, the lizards were tested both in a clean cage and in one sprayed with a pungent odorant. The lizards responded to the snakes' chemicals by increased tongue-flick rates, with the highest rates being given in response to the deposits of their predators. The chemosensory examination of the snakes' odours induced a shift in general behaviour in response to the predator, but not to the non-predator chemical cues. This behavioural response consisted mainly of a disruption of the locomotor patterns. Our findings strongly suggest that lizards detected and distinguished between the chemicals deposited by three species of snake. Behavioural performances were highly variable among individual lizards in all trials, but the relative scores of individuals tended to be similar in response to different stimuli.

Morphology, growth, food habits and population characteristics of the Smooth snake Coronella austriaca in southern Britain

A three year ecological study was made of the Smooth snake in the New Forest, Hampshire. The aim was to provide quantitative information on particular aspects of the Smooth snake's life‐history characteristics. On three study sites, snakes were captured by hand and individually marked. On capture, each snake was identified, sexed, measured, weighed and examined for the presence of food in its stomach and hind gut. In general, mature Smooth snakes showed sexual dimorphism in morphology and growth rates. This was thought to reflect the influence of body size on female reproduction. It was found that Smooth snakes preyed on both small mammals and lizards, suggesting that this species is an opportunist predator. Diet did not vary between study sites. The population sizes were estimated by direct enumeration and densities of one and two snakes per hectare were found. The sex ratios in each study site population were even, and the age structures suggested that both sexes exhibited similar mortality. Consideration was also given to the estimation of the total population size of Smooth snakes in Britain.SummaryThe morphology, growth, food habits and population characteristics of the Smooth snake Coronella austriaca Laurenti were studied in southern England. On capture, each snake was identified, sexed, measured, weighed and examined for the presence of food in its stomach and hind gut.In total, measurements of 22 sexually immature and 92 sexually mature snakes were collected. There was little evidence for sexual dimorphism among immature snakes, though males had relatively longer tails than females. Among mature snakes, females had longer snout‐vent lengths and shorter tails than males. The body weights of breeding females were heavier than those for both non‐breeding females and males. Regardless of age or sex, body weight was positively correlated with snout‐vent length. An analysis of 68 growth measurements revealed that, in common with other species of snake, immature specimens had higher growth rates than mature specimens. Growth within one year did not differ appreciably between males and females. Conversely, growth over more than one year was greatest for female snakes. These differences in morphology and growth were ascribed to the influence that body size has on reproductive success. Large females (i) produce large offspring, and (ii) may have an increased chance of courtship and mating. During non‐breeding years it is suggested that females offset the cost of reproduction through an allocation of energy reserves to bodily growth. Thus individuals may “choose” to grow rather than to breed in particular years. Hence, females in the resting phase of their reproductive cycles may exhibit high growth rates.The Smooth snakes preyed on lizards and small mammals. Nestling prey (young rodents and young shrews taken from underground nests) were the most important dietary items. It was suggested that the Smooth snake is less specialized in its choice of prey than has been previously reported. It was considered to be an opportunist predator, selecting prey according to its availability.Population size was estimated by direct enumeration, and densities of about one and two snakes per hectare were considered representative for this species in Britain. Attention was drawn to the influence that site factors and snake behaviour may have on these calculations. Few immature snakes were captured. It was unclear whether this reflected a higher mortality among these specimens, or whether it was more difficult to find them. The even sex ratio and stable age structure for males and females suggested that mortality was not dependent on the sex of the snakes. Adequate data are lacking for a more comprehensive examination of mortality to be made.An alternative method to the anecdotal estimation of the total population size of Smooth snakes in Britain has been suggested.I wish to record my thanks to Dr I. F. Spellerberg for the advice and support he gave throughout the course of this study. I would also like to thank the Forestry Commission and the Nature Conservancy Council for their permission to undertake this work. Financial support was provided by a University of Southampton Post‐graduate Scholarship. Miss E. C. Meredith and two anonymous referees provided useful comments on parts of this manuscript.