Bufo Calamita Research Articles

Interspecific sensitivity of European amphibians towards two pesticides and comparison to standard test species

BackgroundAlthough debates about the assessment of potential effects of pesticides on amphibians are ongoing, amphibians are not yet considered in the current EU environmental risk assessment of pesticides. Instead, the risk assessment of potential effects on aquatic amphibian life stages relies on use of data of surrogate species like the standard temperate fish species rainbow trout (Oncorhynchus mykiss). This assumption is mainly based on the comparison to amphibian species not native to Europe such as the aquatic African clawed frog (Xenopus laevis). It remains unclear whether these surrogate species cover semi-aquatic Central European amphibian sensitivities. Therefore, we assessed the acute sensitivity of aquatic stages of eight European amphibian species native in Germany (Bufo bufo, Bufotes viridis, Epidalea calamita, Hyla arborea, Pelobates fuscus, Pelophylax sp., Rana dalmatina, R. temporaria) towards commercial formulations of the fungicide folpet (Folpan® 500 SC, Adama) and the insecticide indoxacarb (Avaunt® EC, Cheminova). The determined acute sensitivities (median lethal concentration, LC50) were included in species sensitivity distributions and compared to experimentally determined LC50 values of X. laevis and literature values of O. mykiss.ResultsThe results showed that native amphibian sensitivities differed between the tested pesticides with a factor of 5 and 11. Depending on the pesticide, X. laevis was five and nine times more tolerant than the most sensitive native amphibian species. Comparing literature values of O. mykiss to the experimentally determined sensitivities of the native amphibian species showed that the O. mykiss sensitivity was in the same range as for the tested amphibians for the formulation Folpan® 500 SC. The comparison of sensitivities towards the formulation Avaunt® EC showed an eight times lower sensitivity of O. mykiss than the most sensitive amphibian species.ConclusionsA risk assessment using the 96-h LC50 values for fish covers the risk for the assessed aquatic stages of European amphibians after the application of the recommended uncertainty factor of 100 and thus may be adequate for lower tier risk assessment of the studied pesticides. If aquatic amphibian testing will be required for pesticide risk assessment nevertheless, acute tests with the model organism X. laevis and the application of an appropriate uncertainty factor might be a promising approach.

Amphibians and reptiles as palaeonvironmental proxies during the Late Pleistocene (MIS3): The case of Stratigraphic Unit V of El Salt, Alcoi, Spain

The locality of El Salt (Alcoi, Spain) is a key site for understanding the extirpation of Neanderthals in the eastern part of Iberia. In this paper, we analyse an assemblage of amphibians and reptiles from Stratigraphic Unit V (45.2 ± 3.4 ka to 44.7 ± 3.4 ka), which corresponds to one of the last regional records of Neanderthals, to improve knowledge of the palaeoecology and palaeoclimate of this event. The assemblage comprises three anurans (Pelodytes sp., Alytes obstetricans, and Epidalea calamita), two lizards (Lacertidae indet. and Chalcides bedriagai), and five snakes (Colubridae indet., Coronella sp., Coronella sp./Zamenis sp., Natrix maura, and Vipera latastei). Palaeoclimatic reconstruction, based on the Mutual Ecogeographic Range method, indicates that climate was cooler and slightly wetter climate than the present day climate of the Alcoi area. Applying the Habitat Weighting Method, we infer that the area surrounding El Salt was dominated by open dry regions, alternating with rocky areas with scarce scrubs and forest patches that would have developed under mesomediterranean conditions. These results are not entirely consistent with those obtained with other proxies (charcoal and small mammal assemblages) from the same site, which suggest slightly warmer and drier conditions. We hypothesise that these divergences may be partly related to the current wide distribution of reptiles and amphibians across Iberia. A key finding is that the extirpation of the Neanderthals in Iberia coincided with aridification.

Small vertebrates from a Holocene gravelly deposit at El Salt (Alcoi, Alicante)

The small-vertebrates’ assemblage recovered comes from Units I to IV from El Salt site (Alcoi, Spain). The sample is composed by nearly 310 remains, and includes one toad (Epidalea calamita), two lizards (Lacertidae indet. and Chalcides cf. bedriagai), two snakes (Coronella cf. girondica and cf. Coronella sp.), two insectivores (Crocidura sp. and Sorex sp.), one lagomorph (Oryctolagus cuniculus) and seven rodent taxa (Arvicola sapidus, Microtus sp., M. arvalis, M. cabrerae, M. duodecimcostatus, Apodemus sylvaticus, and Eliomys quercinus). All the species described in the present work are consistent with a Late Pleistocene-Holocene chronology. The presence of M. cabrerae (absent in the Middle Pleistocene) and M. duodecimcostatus (absent in the Mediterranean until the Late Pleistocene) seem to confirm this age. The presence of Neolithic pottery and M. arvalis in the same deposit is inconsistent from a biochronically point of view since this species was extirpated from this region at the end of the Late Pleistocene. Several taphonomic alterations related to transport within the small mammal remains have been identified. Further taphonomical and geoarchaeological work is needed to clarify the provenience of the studied faunal assemblages, which, given the high energy, erosional morphology and lithology of the sedimentary deposit, could have been reworked in a more recent time period.

Will predicted positive effects of climate change be enough to reverse declines of the regionally Endangered Natterjack toad in Ireland?

The global amphibian crisis is driven by a range of stressors including disease, habitat loss, and environmental contamination. The role of climate change remains poorly studied and is likely to influence environmental suitability, ranges, reproduction, and phenology. This study aimed to characterize the bioclimatic‐habitat niche space of the Natterjack toad (Epidalea calamita) throughout its European range and to assess the impact of climate on the toad's environmental suitability and breeding behavior in Ireland, where declines in recent decades have resulted in it being regionally Red‐Listed as Endangered. To address these questions, we first identified which climate variables best predict the current bioclimatic niche, fecundity (number of eggs deposit), and phenology. We then used future climate projections for two time periods (2041–2060 and 2061–2080) and two greenhouse gas emission scenarios (RCP 4.5 and RCP 8.5) to predict how the species range, fecundity, and phenology would change. The European range of the species was found to be limited by winter temperatures while its bioclimatic niche varied markedly throughout its range. Species distribution models suggested projected climate change will increase environmental suitability for the species throughout its range, including Ireland, but most notably in Scandinavia and the Baltic. Fecundity in Ireland was greatest during the cool temperatures of spring and after wet winters associated with ephemeral breeding pool availability. Warm, dry summers in the preceding year influenced fecundity the following spring indicative of carryover effects. Initiation of spawning was driven by spring temperatures, not rainfall. Projections suggested future climate change may increase fecundity in Ireland while spawning may commence earlier throughout the 21st century especially under a high greenhouse gas emission scenario (RCP 8.5). Despite recent range contraction and population declines due to habitat deterioration, the Natterjack toad, if subject to a suitable species conservation strategy, has the potential to be a climate change winner, notwithstanding unpredictable habitat and land‐use change, sea‐level rise inducing coastal erosion, changes in invertebrate prey abundance, and disease.

Are Iberian ribbed newts Pleurodeles waltl Michahelles, 1830 negatively affecting the populations of other amphibians?

AbstractTemporary ponds play a key role as amphibian breeding habitats, but predation and desiccation risks enforce major evolutionary pressures in these ecosystems. The newt Pleurodeles waltl is commonly found in Mediterranean ponds in the Iberian Peninsula, where it preys on a wide variety of organisms. We hypothesize that P. waltl may negatively influence populations of coexisting amphibian larvae in the natural environment. To test it, we monitored the amphibian populations of 21 temporary ponds in Eastern Spain, 10 of which included P. waltl. We visited each pond fortnightly on nine occasions, estimating the abundance of adult P. waltl and tadpoles of each amphibian species present. We built zero‐inflated Generalized Linear Mixed Models (GLMMs) to test for the effects of pond area and adult and larval P. waltl abundance on tadpole abundance of all amphibian species present. Our results show significant negative effects of P. waltl abundances on the anurans Alytes obstetricans, Epidalea calamita, and Pelodytes punctatus. Species adapted to shorter hydroperiods such E. calamita and P. punctatus show lower densities in the presence of P. waltl larvae. A. obstetricans, with preference for longer hydroperiod ponds, seems to better thrive in sites where the newt is absent. This is the first field work suggesting a negative impact of P. waltl on coexisting anurans, even though more studies are needed to disentangle other negative effects related to unmeasured environmental variables or biotic interactions, which can be important according to the large variation encompassed by the random variables of site and sampling period in the mixed models.

A multistep approach to improving connectivity and co-use of spatial ecological networks in cities

ContextEcological networks are systems of interconnected components that support biodiversity, ecological processes and ecosystem services. Such structures play a crucial role for nature conservation and people well-being in anthropogenic landscapes. Assessing connectivity by using efficient models and metrics is a sine qua non condition to preserve and improve appropriately these ecological networks.ObjectivesThis study aims to present a novel methodological approach to assess and model connectivity for species conservation (Bufo calamita; the natterjack toad) and human recreation in the city.MethodsThe study used a combination least cost and circuit models to identify priority corridors in the City of Liège, Belgium. Green areas, habitats and relevant movement parameters were derived based on existing studies around (i) the occurrence, ecology and biology of the natterjack toad and (ii) human behavioural studies on urban pedestrians. Combining the two models allowed the assessment of connectivity for both species via two different metrics visualised using priority corridors on maps.ResultsThe connectivity assessments identified lack of connectivity as the potential route to extinction of natterjack toads at one of the source sites.ConclusionsThis study provides examples of how combining least cost and circuit models can contribute to the improvement of urban ecological networks and demonstrates the usefulness of such models for nature conservation and urban planning.

Обзор методик зоокультуры редких и исчезающих земноводных России и сопредельных стран: опыт Тимирязевской академии

This article discusses the problems of rare amphibian zooculture, artificial reproduction over several generations. Amphibians have been bred in Russia for at least 150 years, but only a small number of species have become widely distributed in captivity. However, to date, the offspring of most amphibians included in the Red Data Book of the Russian Federation have been obtained under laboratory conditions, and since 2008, the Timiryazev Academy (Russian State Agrarian University – Moscow Timiryazev Agricultural Academy) has been working on the introduction of five species into the culture (Lissotriton lantzi, Ommatotriton ophryticus, Triturus karelinii, Bufo verrucosissimus и Epidalea calamita). Two-to-four generations of these species were obtained under artificial conditions and work was carried out to identify optimal content densities, temperature conditions, photoperiod, and diet. This enabled technology of laboratory reproduction to be developed. This review presents some original methods for housing, feeding, and breeding these species. We believe that the main obstacle for implementation to the zooculture of rare amphibian species in Russia and neighboring countries is the shortage of live food insects; this drawback does not allow us to create sufficiently large and genetically diverse groups of amphibians. One promising area of research is the search for new feed objects that have high nutritional value, simplicity, and low cost of cultivation as well as a high rate of biomass growth.

Can age and growth patterns explain the geographical variation in the body size of two toad species?

Determining both the age structure and growth pattern allows to establish the causal factors, environmental and/or genetic, that eventually may be responsible for the observed pattern of divergence. We examined the variation in age structure and growth pattern across populations of two toad species, Pelobates cultripes and Epidalea calamita that exhibit a geographic variation in body size in southern Spain. For both species, populations differed in mean age but age structure did not correlate with body size variation across populations. Although the population with the youngest females found for E. calamita was the smallest in body size, the oldest males for both species were found in a small body size population. The growth pattern fit well to a von Bertalanffy growth model and interdemic divergence were found for both the asymptotic body size (Sm ) and the growth coefficients (k). As expected, Large-Bodied populations of both species attained higher Sm but, Small-Bodied population had higher, although non significantly different, k growth coefficients. Also, the Small-Bodied population attained sexual maturity sooner but had also high longevity. The observed pattern may reflect both environmental variations in resources availability affecting body size observed across populations, but also different growth and maturity pathways that may respond to contrasting selective pressures.

Porównawcza ocena programów analizy żywotności populacji (PVA) w rankingu scenariuszy przekształceń krajobrazu = A comparative assessment of PVA software packages applied to rank the landscape management scenarios

Because of the scale and speed of species extinctions conservationists require methods that facilitate decision making. Therefore, a wide range of habitat and population viability analysis (PVA) software has been developed. Given the diversity of available programs it is currently challenging to decide which program is the most appropriate for a particular problem and what has to be considered when interpreting and comparing results from different approaches. Previous comparisons of PVA software addressed more generic questions such as data requirements, assumptions and predictive accuracy. In contract, we focus on a more applied problem that is still unresolved: how do simple habitat models and PVA software packages affect the ranking of alternative management scenarios? We addressed this problem by comparing different packages (LARCH, META-X, VORTEX and RAMAS GIS). As a test case, we studied the impact of alternative landscape development scenarios (river regulation, grassland restoration, reforestation and renaturalisation) for the Vistula valley, Poland, on the natterjack toad (Bufo calamita). In this context we also aimed to assess whether the use of at least two different PVA packages can enable users to better understand the differences in model predictions, which would imply a greater awareness and critical use of the packages. Our model selection represents different approaches to population viability analysis, including habitat, local population and stochastic patch occupancy models. The models can be evaluated in regard to the complexity of parameters and to the way the landscape is handled. We used RAMAS GIS to create a habitat model (RAMASh) and a detailed spatially explicit stochastic metapopulation model (RAMASp) which combined served as a complete “virtual” dataset for parameterisation of other programs. As an example of a stochastic patch occupancy model, we selected the META-X software. For a more independent comparison we added VORTEX – another package that includes explicit population dynamics, similar to RAMAS. Additionally, we included the habitat model LARCH because this type of model is often used by policy makers. We compared the metapopulation structure produced by RAMASh and LARCH. Scenario ranking according to the predicted carrying capacity in both programs was exactly the same, because the quantitative results for each scenario were almost identical in both programs. However, the metapopulation structure showed big differences between the programs, especially in the number of small populations. The analyses of results of different PVA programs (RAMASp, VORTEX and META-X) showed that absolute values of viability measures partly differed among these programs. Slight differences in population growth rate in RAMASp and VORTEX were amplified by stochasticity and resulted in visibly lower values of final abundance in VORTEX than in RAMASp. Also the absolute values of intrinsic mean time to extinction showed some discrepancies in VORTEX and META-X. These results are in agreement with findings of previous PVA comparisons, which emphasizes that absolute values of viability measures produced by any single model should be treated with caution. Nevertheless, despite these differences the rankings of the scenarios were the same in all three programs. However the order of the scenarios was different than in habitat models. In addition, these rankings were robust to the choice of viability measure. Taken together, these results emphasize that scenario ranking delivered by PVA software is robust and thus very useful for conservation management. Furthermore, we recommend using at least two PVA software packages in parallel, as this forces user to scrutinize the simplifying assumptions of the underlying models and of the viability metrics used.

Determining the effects of sperm activation in anuran cloaca on motility and DNA integrity in Epidalea calamita (Bufonidae).

The effect of time inside the animal's cloaca on sperm quality after hormone-induced spermiation is unknown. However, this knowledge is critical for the development of assisted reproductive biotechnologies in amphibians. Out-of-season spermatozoa were collected from Epidalea calamita for 4h after injection of 10IU g-1 human chorionic gonadotrophin either hourly (Group I (n =10); four samples per male) or every 2h (Group II (n =9); two samples per male). Sperm samples were assessed for motility and DNA integrity using the sperm chromatin dispersion (SCD) test and the sperm chromatin structure assay (SCSA). The collection strategy affected total motility (mean (±s.e.m.) 84.4±9.9% vs 73.6±16.7% in Group I and II respectively; P =0.014) and the sperm motility index (67.6±17.7% vs 57.6±16.3% in Group I and II respectively; P =0.034). There was a significant effect of the male in Group II, but not in Group I. In Group I, the quality of the first samples collected was lower than that of samples collected thereafter (P ≤ 0.032). No significant correlations were found between the results of the SCD test and SCSA, showing that these techniques provide different information in this species. In conclusion, collecting spermatozoa every hour resulted in better sperm quality and may be more efficient. However, the between-male differences were considerable and collection of spermatozoa at just 1h after hormone treatment produced lower-quality spermatozoa.

Combining spawn egg counts, individual photo-ID and genetic fingerprinting to estimate the population size and sex ratio of an endangered amphibian.

According to the International Union for Conservation of Nature Red List, 41% of the world's amphibian species are threatened with extinction, making them more threatened than any other vertebrate group nowadays. Given the global amphibian crisis, comprehensive understanding of demographics and population trends of declining and threatened species is essential for effective management and conservation strategies. Counting egg spawns is widely used to assess population abundance in pond breeding anurans. However, it is unknown how such counts translate into robust population size estimations. We monitored the breeding activity of the Natterjack toad (Epidalea calamita), combining egg string counts and individual photo-identification with Capture-Mark-Recapture population size and operational sex ratio estimation. Male Natterjack toads were identified by the pattern of natural markings with repeated ID of the same individual confirmed for 10% of the samples using genetic fingerprinting. We identified 647 unique individuals within a closed study population at Caherdaniel, Co Kerry. Population estimates derived from egg string counts estimated a breeding population of 368 females (95% CI 353-384) and Capture-Mark-Recapture estimated a breeding population of 1698 males (95% CI 1000-2397). The female:male sex ratio was conservatively estimated at 1:5 (95% CI 1:3-1:6) where 62% ± 6% of females were assumed to spawn. These substantially departed from any priori assumption of 1:1 which could have underestimated the breeding population by up to 72%. Where amphibian absolute population size estimation is necessary, methods should include empirical survey data on operational sex ratios and not rely on assumptions or those derived from the literature which may be highly population and/or context-dependent.

Comparison of landscape graph modelling methods for analysing pond network connectivity

Landscape fragmentation negatively impacts species populations by isolating them. Assessing landscape connectivity could help to improve biodiversity conservation. Among various methods available to model and analyse connectivity, graph-theoretic approaches are recognized as powerful tools, even if their ecological significance may be questionable in some cases. Indeed, there are many ways to construct a landscape graph and their impacts on the assessment of connectivity are rarely explored. Our aim was to compare three methods of constructing landscape graphs to identify differences and similarities in the resulting network connectivity. The methods can be distinguished according to the type of data used: expert opinions, field data or a combination of the two. The methodological framework was applied to seven pond-dwelling species (Alytes obstetricans, Bufo bufo, Epidalea calamita, Hyla arborea, Natrix natrix, Rana temporaria, Triturus cristatus) in the Ile-de-France region (France). Three common methods were applied to construct landscape graphs: (1) using a land cover map (LM) and expert opinions to define nodes and links; (2) using a habitat suitability model (HSM) and species occurrence data to define nodes and links; and (3) using a HSM to define nodes and a land cover map to define links (HSM_LM). To carry out our study, we produced a land cover map, collected and prepared input data for HSMs, generated HSMs to map the probability of species occurrence and constructed landscape graphs from the three methods. For each of them, several connectivity metrics were calculated and compared. The results revealed large differences in the statistical distribution of connectivity values, even though the spatial location of the main areas of low and high connectivity was roughly the same. In general, the LM method provided lower values of connectivity and smaller areas of high values than the other two, regardless of species. Conversely, the HSM method had the highest connectivity values, while the combined HSM_LM method appeared to be intermediate. Our study was not intended to conclude whether one method is better than another; only to point out that results vary greatly depending on the graph construction method. To evaluate the predictive performance of each model, a validation process should be conducted with another independent biological dataset, which was not available in our study. The high variability of results argues for taking care to ensure that the construction of models is carefully consistent with ecological assumptions and the objective pursued.

Combining spatial modeling tools and biological data for improved multispecies assessment in restoration areas

Habitat restoration is one of the actions to reduce landscape fragmentation by promoting connectivity and thus biodiversity. But knowing where to implement these habitats is a major issue and planners lack guidance for answering this question, in particular when it involves multiple species and over a large area. We proposed to combine biological data, habitat suitability models and spatial graphs to improve multiscale and multispecies connectivity in Ile-de-France, a highly artificialized region of 12,000 km2. The framework consisted of i) modeling habitat suitability for eight pond-dwelling species (Alytes obstetricans, Bufo bufo, Epidalea calamita, Hyla arborea, Rana temporaria, Salamandra salamandra, Triturus cristatus, and Natrix natrix), ii) modeling the ecological network for each species, iii) prioritizing each sampling point depending on the gain in connectivity if a new pond was created there and iv) combining single-species results to identify the areas that could improve multispecies connectivity. The multivariate statistical analysis revealed that transitional forest environments appeared to be the most strategic areas for improving multispecific connectivity (at least for 5 species). Targeted addition of habitat within an ecological network can increase habitat density in deficient areas and reconnect network sub-parts. This approach is therefore promising to guide conservation actions and “no net loss” biodiversity measures, especially the final stage of offset in the mitigation hierarchy.

Effect of seasonality on hormonally induced sperm in Epidalea calamita (Amphibia, Anura, Bufonidae) and its refrigerated and cryopreservated storage

An understanding of how seasonality impacts amphibian's sperm quality is crucial for the development and implementation of assisted reproductive technologies for threatened species. We analysed sperm quality both within and outside the breeding season for the common natterjack toad (Epidalea calamita) in a population close to Madrid (Spain). Fresh hormonally induced sperm samples were assessed for sperm concentration, total activated sperm (TAS), forward motility (FM), quality of motility (QM) and DNA integrity (DNAi). Motility and DNAi were re-evaluated after cold-storage at 5 °C for 24 h. After freezing and thawing DNAi was re-analysed and a fertilization trial performed to test post-thaw sperm functionality. More males presented sperm after hormone administration during the breeding season compared to out of season (78.3 vs. 52.2%), although the difference was not significant. Fresh sperm motility and DNAi were not affected by season (p > 0.05). However, sperm concentration was higher (p = 0.037) during the breeding season (5.2 vs. 2.9 × 106 sperm/ml). After cold-storage sperm obtained in the breeding season presented higher FM (36.1 ± 4.6 vs. 22.0 ± 3.5%; p = 0.013) and QM (1.28 ± 0.2 vs. 0.68 ± 0.2; p = 0.017) than samples from out of season. DNAi decreased after freeze-thawing in both seasons (p < 0.01) but no differences were found between seasons. Fertilization experiment showed that neurulas were found in 72.7% (outside breeding season) and 68.8% (breeding season) sperm samples. Later, hatched embryos were observed in 18.2% (outside breeding season) and 56.3% (breeding season) sperm samples and the percentage of embryos was higher (p = 0.026) in sperm samples from males collected during the breeding season (38.4 ± 6.9 vs. 3.5 ± 0.2% embryos/sample). Overall, sperm obtained during the breeding season had a higher sperm concentration, was less sensitive to cold temperatures and maintained a better fertilization capacity after cryopreservation. Therefore, seasonality affects sperm quality and should be considered when planning sperm collection for assisted reproductive technologies.

The importance of long-term genetic monitoring of reintroduced populations: inbreeding in the natterjack toad (Epidalea calamita)

Genetic monitoring is an important, but frequently lacking, component of management actions to support long-term persistence in reintroduced populations. Populations that remain small, due to demographic processes and genetic diversity, are more likely to experience a second extinction event. The natterjack toad (Epidelea calamita) is legally protected in Britain and was the subject of a reintroduction programme in the 1990s. However, subsequent genetic assessment has been mostly lacking. The aim of this study was to assess the genetic diversity of two reintroduced populations of natterjack toads in order to inform conservation management. Adults were sampled and nine microsatellites amplified to assess neutral genetic variation within each site and for comparison with the source population. Inbreeding was observed at the reintroduction sites, as evidenced by high FIS values (0.43 and 0.72), low observed compared to expected heterozygosities, and significant deviation from Hardy-Weinberg equilibrium. Observed heterozygosity is currently lower in the reintroduction sites than it was in the source population at the time of the reintroductions (Red Rocks: 0.15±0.20; Talacre: 0.12±0.20; Ainsdale (source): 0.29). Evidence for a bottleneck was not found, although this is likely a result of sampling overlapping generations. No withinsite population structuring was observed. Such low genetic diversity has not previously been recorded in any natterjack population. Genetic rescue, combined with pool creation, is the most viable option for safeguarding the species at these sites into the future. Our work highlights the importance of ongoing genetic monitoring, in collaboration with conservation organisations, to support conservation management.

Telomere attrition with age in a wild amphibian population.

Telomere shortening with age has been documented in many organisms, but few studies have reported telomere length measurements in amphibians, and no information is available for growth after metamorphosis, nor in wild populations. We provide both cross-sectional and longitudinal evidence of net telomere attrition with age in a wild amphibian population of natterjack toads (Epidalea calamita). Based on age-estimation by skeletochronology and qPCR telomere length measurements in the framework of an individual-based monitoring programme, we confirmed telomere attrition in recaptured males. Our results support that toads experience telomere attrition throughout their ontogeny, and that most attrition occurs during the first 1-2 years. We did not find associations between telomere length and inbreeding or body condition. Our results on telomere length dynamics under natural conditions confirm telomere shortening with age in amphibians and provide quantification of wide telomere length variation within and among age-classes in a wild breeding population.

A Wall Cavity as a Diurnal Retreat Site for Young Natterjack Toads

Birinci ve ikinci yılındaki Haçlı Kara kurbağaları (Epidalea calamita)'nın Hollanda kıyı kumullarının yakınında ilkbahardan sonbahara kadar bir binanın tuğla duvarında yer alan bir boşluğu ortak diurnal sığınak olarak kullandıkları tespit edilmiş ve aynı zamanda bu sığınağın kış sığınağı olabileceğinden şüphelenilmiştir. Sadece juveniller ve ikinci yılındaki bireyler gözlenmiştir. Daha büyük örnekler boşluğun önündeki metal ağdan dolayı girememiştir.

Dwarfism in close continental amphibian populations despite lack of genetic isolation

Ample variation in body size is common in vertebrates over extensive geographical distances, or in isolated populations, where effective geographical barriers may cause dwarfism or gigantism. Here we study potential causes of extreme size reduction in continental populations of amphibians within a short geographical distance and in the absence of geographical barriers. Natterjack toads Epidalea calamita in Doñana National Park (Spain) experience up to 2.1‐fold difference in body mass in as little as 37 km. Studying six populations divergent in body size, we tested for genetic isolation of the dwarf populations using multilocus genotypes (16 microsatellites), and explored whether populations differ in trophic status (through stable isotope analysis), standard metabolic rate and growth pattern, senescence and age structure (conducting telomere length assays and skeletochronology). We also recorded advertisement calls across populations and experimentally tested for behavioural reinforcement of the body size variation through female preferences. Local dwarfism in these populations occurs in the absence of genetic isolation while maintaining relatively high effective population sizes. Dwarf populations, however, are exposed to drier and warmer climatic conditions, have different trophic status, show lower mass‐specific metabolic rate, and male advertisement calls with a higher dominant frequency. Juvenile growth differed among populations, reaching the adult stage at different body sizes. Altogether, our results suggest a significant influence of environmental conditions on the physiology and ecology of the Doñana E. calamita populations, mainly affecting toads between metamorphosis and sexual maturity. Further experimental and genomic studies focusing on these early life stages are necessary to dissect the relative roles of the environment and adaptive genetic differentiation on this phenomenon.

Amphibians and squamate reptiles from the stratigraphic unit Xb of El Salt (Middle Palaeolithic; Alcoy, Spain): palaeoenvironmental and palaeoclimatic implications

The locality of El Salt (Middle Paleolithic, Alcoy, Spain) is mainly known by having one of the youngest Neanderthals records of the southeastern Iberian Peninsula. In this work, we have analysed the herpetofaunal fossils from the upper part of stratigraphic unit Xb, dated at 52.3 ± 4.6 ka (MIS 3). The faunal list is composed by three taxa of anurans (Alyte obstetricans, Bufo bufo s.l., and Epidalea calamita), one taxon of blanid (Blanus cinereus s.l.), two taxa of lizards (Chalcides bedriagai and cf. Acanthodactylus erythrurus), and one taxon of snakes (cf. Rhinechis scalaris). All of them have a broad distribution range in the Mediterranean, with wide ecological preferences range. This association of amphibians and reptiles from the Unit Xb suggests a slightly warmer and more humid climate than the current one; with an annual temperature range less accused and a similar seasonality of the rainfall than it is recorded nowadays in Alcoy. These results may correspond to a warm period (Daansgard-Oeschger event) during the MIS 3. A landscape composed by bushland and forest patched in which some open areas were present, with presence of permanent water bodies in the nearby areas, would characterize the surroundings areas of El Salt.

Digressions on Davis and the Natterjack Toad

A series of humorous anecdotes about the author’s friendship with Geoff Davis and a poem written in his honour.