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Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 populations (77 species) of nonavian reptiles and amphibians. We test hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life history contribute to demographic aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates compared with endotherms and include phylogenetically widespread evidence of negligible aging. Protective phenotypes and life-history strategies further explain macroevolutionary patterns of aging. Analyzing ectothermic tetrapods in a comparative context enhances our understanding of the evolution of aging.

Identifying the drivers of population fluctuations in spatially distinct populations remains a significant challenge for ecologists. Whereas regional climatic factors may generate population synchrony (i.e. the Moran effect), local factors including the level of density dependence may reduce the level of synchrony. Although divergences in the scaling of population synchrony and spatial environmental variation have been observed, the regulatory factors that underlie such mismatches are poorly understood. Few previous studies have investigated how density-dependent processes and population-specific responses to weather variation influence spatial synchrony at both local and regional scales. We addressed this issue in a pond-breeding amphibian, the great crested newt Triturus cristatus. We used capture-recapture data collected through long-term surveys in five T. cristatus populations in Western Europe. In all populations-and subpopulations within metapopulations-population size, annual survival and recruitment fluctuated over time. Likewise, there was considerable variation in these demographic rates between populations and within metapopulations. These fluctuations and variations appear to be context-dependent and more related to site-specific characteristics than local or regional climatic drivers. We found a low level of demographic synchrony at both local and regional levels. Weather has weak and spatially variable effects on survival, recruitment and population growth rate. In contrast, density dependence was a common phenomenon (at least for population growth) in almost all populations and subpopulations. Our findings support the idea that the Moran effect is low in species where the population dynamics more closely depends on local factors (e.g. population density and habitat characteristics) than on large-scale environmental fluctuation (e.g. regional climatic variation). Such responses may have far-reaching consequences for the long-term viability of spatially structured populations and their ability to respond to large-scale climatic anomalies., (© 2020 British Ecological Society.)

In the south of France, the so-called climate hiatus from 1998 to 2013 was associated with a late winter cooling which has affected the phenology of several reptiles and amphibian species, delaying their dates of first appearances in spring. This episode has been related to a period of frequently negative values of the North Atlantic Oscillation index (NAO i ). The recent increase of this index after this episode marks the end of the "hiatus" and provides an opportunity to verify the impact of the North Atlantic Oscillation (NAO) on the fauna of the North Mediterranean region. Most of the emergence dates of amphibians and reptiles in spring have rapidly advanced from 1983 to 1997 and then receded or stabilized from 1998 to 2010. They began to advance again since 2010. These phenological changes covary with the temperature of February-March in the study area, which is itself related to the variations of the NAO index. These changes confirm the influence of the NAO on the phenology of terrestrial organisms in northern Mediterranean where its influence is sometimes assumed to be attenuated.

Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum., (© 2017 John Wiley & Sons Ltd.)

Global biodiversity in freshwater and the oceans is declining at high rates. Reliable tools for assessing and monitoring aquatic biodiversity, especially for rare and secretive species, are important for efficient and timely management. Recent advances in DNA sequencing have provided a new tool for species detection from DNA present in the environment. In this study, we tested whether an environmental DNA (eDNA) metabarcoding approach, using water samples, can be used for addressing significant questions in ecology and conservation. Two key aquatic vertebrate groups were targeted: amphibians and bony fish. The reliability of this method was cautiously validated in silico, in vitro and in situ. When compared with traditional surveys or historical data, eDNA metabarcoding showed a much better detection probability overall. For amphibians, the detection probability with eDNA metabarcoding was 0.97 (CI = 0.90-0.99) vs. 0.58 (CI = 0.50-0.63) for traditional surveys. For fish, in 89% of the studied sites, the number of taxa detected using the eDNA metabarcoding approach was higher or identical to the number detected using traditional methods. We argue that the proposed DNA-based approach has the potential to become the next-generation tool for ecological studies and standardized biodiversity monitoring in a wide range of aquatic ecosystems., (© 2015 John Wiley & Sons Ltd.)

For effective conservation, robust tools that can measure and predict spatio-temporal population variation are required, especially for species in steep decline, rarely encountered or difficult to detect, such as many amphibian species. This study focused on the relevance of the Habitat Suitability Index (HSI) and its component variables to assess habitat and predict the presence of the great crested newt (Triturus cristatus) in the southern margin of its range. We monitored the species to test (1) the effectiveness of different methods for detecting newts, and (2) the influence of different landscape variables on its occupancy probability. Our results indicate that while eDNA is a highly effective detection tool, it is not sufficient on its own to detect all occupied ponds by the great crested newt, that HSI is not a good predictor of pond occupancy at the range margins of this species, and that the species' presence is significantly and negatively influenced by the distance to the nearest positive pond and the HSI pond drying. Our findings suggest that the conservation of the species in the southern margins of its range can only be achieved by maintaining the terrestrial and aquatic connectivity of the different identified populations. [ABSTRACT FROM AUTHOR]

Habitat anthropization is a major driver of global biodiversity decline. Although most species are negatively affected, some benefit from anthropogenic habitat modifications by showing intriguing life-history responses. For instance, increased recruitment through higher allocation to reproduction or improved performance during early-life stages could compensate for reduced adult survival, corresponding to "compensatory recruitment". To date, evidence of compensatory recruitment in response to habitat modification is restricted to plants, limiting understanding of its importance as a response to global change. We used the yellow-bellied toad (Bombina variegata), an amphibian occupying a broad range of natural and anthropogenic habitats, as a model species to test for and to quantify compensatory recruitment. Using an exceptional capture-recapture dataset composed of 21,714 individuals from 67 populations across Europe, we showed that adult survival was lower, lifespan was shorter, and actuarial senescence was higher in anthropogenic habitats, especially those affected by intense human activities. Increased recruitment in anthropogenic habitats fully offset reductions in adult survival, with the consequence that population growth rate in both habitat types was similar. Our findings indicate that compensatory recruitment allows toad populations to remain viable in human-dominated habitats and might facilitate the persistence of other animal populations in such environments. [ABSTRACT FROM AUTHOR]

Connectivity in pond ecosystems is essential for amphibian population persistence. To test the role of connectivity, a diversity of scales accounting for the different processes underlying species distribution needs to be considered. Several approaches exist for accounting for the potential connectivity, mainly based on structural versus functional methods. Based on occupancy data, our aim was to assess the relative power of connectivity metrics in explaining amphibian distribution when accounting for cross‐scale effects from pond to network scales, and to identify network features relevant to amphibian conservation in agricultural landscapes in the Seine‐et‐Marne department (east of Paris, France).We propose an original analytical framework that allows examining different spatial scales of influence, with a focus on connectivity. We analyse the distribution of three amphibian species (Bufo bufo, Rana dalmatina, and Lissotriton vulgaris) in relation to various pond conditions (fish presence, water quality, and nearby woodland habitat) as well as connectivity using three connectivity approaches: (1) structural, (2) area‐functional based on potential migration areas, and (3) path‐functional based on the least accumulated cost paths. Values of landscape resistance were assigned according to a biological risk‐based approach that is proposed as an enhanced, transparent expert‐based approach. We further investigated cross‐scale effects in amphibian responses to the environment by assessing the relative importance of pond and network characteristics as well as their interactions.Despite some species‐specific characteristics, the area‐functional approach of connectivity was generally the most effective in explaining species distribution by emphasising the relevance of potential migration areas as conservation units. Although pond conditions usually had a greater influence than network connectivity, we highlighted important cross‐scale and threshold effects in species' response to local conditions, to pond connectivity, and to the availability of potentially suitable terrestrial habitats in the networks.Our cross‐scale approach accounts for scale‐dependent processes that potentially underlie amphibian distribution such as habitat selection and metapopulation dynamics. Both structural and functional connectivity should be considered as complementary features of pond connectivity when dispersal traits are likely to be less limiting. From a management perspective, our results encourage conservation plans to combine functional network‐centred strategies with the preservation of local conditions. We give guidelines as to the features of such networks to help maintain amphibian populations in agricultural landscapes. [ABSTRACT FROM AUTHOR]

Highlights • Traditional hedgerow landscapes are profoundly affected by agricultural intensification. • Amphibian richness is determined by both landscape and breeding site attributes. • Crop farming negatively influence landscape heterogeneity and amphibian diversity. • Wood patches have a positive effects even within areas with intensive practices. • High habitat structural heterogeneity is favorable to a diversity of amphibians. Abstract Agricultural intensification is responsible for major habitat degradation and is a primary cause of biodiversity loss. Amphibians are currently facing a global decline induced by multiple pressures, including notably habitat degradation and land conversion. In western Europe, traditional farming systems involve a dense hedgerow network with a mosaic of pastures, cultivated fields, ponds, and small woods. These heterogeneous landscapes are particularly favorable for biodiversity but their role for amphibian conservation remain understudied. We studied the amphibian community (15 species) of a hedgerow network landscape in western France. We described 79 cattle ponds and tested the influence of ponds characteristics as well as the surrounding landscape composition on species occurrence. Amphibian diversity was positively influenced by breeding site vegetation and also ponds density in the surrounding landscape. We also found positive effects of wood patches and hedgerow linear at a small spatial scale. In turn, crop cover and road linear negatively influenced amphibian richness at large spatial scale. Important variation were detected among species reflecting contrasted life history traits. Our results underline that traditional pastoral landscapes provide a high density of breeding sites and habitats favorable for a diversity of amphibian species. [ABSTRACT FROM AUTHOR]

Dispersal (i.e. movement from a natal or breeding site to another breeding site) is a central process in ecology and evolution as it affects the eco‐evolutionary dynamics of spatially structured populations. Dispersal evolution is regulated by the balance between costs and benefits, which is influenced by the individual phenotype (i.e. phenotype‐dependent dispersal) and environmental factors (i.e. condition‐dependent dispersal). Even though these processes have been extensively studied in species with simple life cycles, our knowledge about these mechanisms in organisms displaying complex life cycles remains fragmentary. In fact, little is specifically known about how the interplay between individual and environmental factors may lead to alternative dispersal strategies that, in turn, lead to the coexistence of contrasted site fidelity phenotypes. In this paper, we examined breeding dispersal in a pond‐breeding amphibian, the great crested newt Triturus cristatus, within usual walking distances for a newt. We took advantage of recent developments in multi‐event capture–recapture models and used capture–recapture data (946 newts marked) collected in a spatially structured population occupying a large pond network (73 ponds). We showed a high rate of breeding site infidelity (i.e. pond use) and the coexistence of two dispersal phenotypes, namely, a highly pond faithful phenotype and a dispersing phenotype. Individuals that were site faithful at time t – 1 were therefore more likely to remain site faithful at time t. Our results also demonstrated that the probability that individuals belong to one or the other dispersal phenotypes depended on environmental and individual factors. In particular, we highlighted the existence of a dispersal syndrome implying a covariation pattern among dispersal behavior, body size, and survival. Our work opens new research prospects in the evolution of dispersal in organisms displaying complex life cycles and raises interesting questions about the evolutionary pathways that contribute to the diversification of movement strategies in the wild. [ABSTRACT FROM AUTHOR]

Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation ( NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life ( T. cristatus), whereas recruitment was most impacted in species with a slower pace of life ( B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum. [ABSTRACT FROM AUTHOR]

Species that occur in ephemeral habitats such as temporary waterbodies have evolved specific strategies that allow them to respond to spatial and temporal variations in water availability and quality. Their life-history strategies, involving complex life cycles, have evolved to allow individuals to escape deteriorating environmental conditions when a waterbody dries up. These adaptations have led to the emergence of complex movement behaviour, which might then be expected to affect the spatiotemporal dynamics of reproduction., To date, few empirical studies have investigated how the risks of waterbody drying out affects movement behaviour at the individual level and how movement decisions then shape waterbody occupancy dynamics. In this study, we examined this issue in an endangered amphibian, the yellow-bellied toad ( Bombina variegata). For this purpose, we experimentally manipulated waterbody hydroperiod and collected capture-recapture and presence-absence data in 334 waterbodies located in 15 B. variegata populations in the region of Geneva (Switzerland) during a 5-year period (2012-2016)., The results of our analyses reveal that the waterbody hydroperiod affects this species' movement behaviour. Adults were less likely to leave waterbodies with a long hydroperiod both intra- and inter-annually. In addition, breeding occupancy strongly depended on a waterbody's hydroperiod. In particular, interannual changes in breeding occurrence were less frequent in waterbodies with a long hydroperiod., Our findings show that the hydroperiod strongly affects ecological processes at different levels, from individuals' movement decisions to waterbody occupancy dynamics. The results demonstrate that adults adjust their movement decisions according to the risk of breeding failure driven by the hydroperiod, which then affects the waterbody occupancy dynamics. [ABSTRACT FROM AUTHOR]

Dispersal is a central component of life history evolution. An increasing number of studies suggest that spatiotemporally variable environments may promote the evolution of 'dispersal syndromes,' consisting of covariation patterns between dispersal and morphological, physiological, behavioral, and life history traits. At the interspecific scale, the 'colonizer syndrome' appears to be one of the most frequently recorded associations between dispersal and life history traits, linking a high dispersal rate, high fecundity, and a short lifespan as systematically combined adaptations in spatiotemporally varying environments. However, few studies have highlighted the existence of a 'colonizer syndrome' at the intraspecific scale, and none have investigated how different degrees of habitat stochasticity might shape covariation patterns between dispersal and life history traits. In this study, we examined this issue in free-ranging metapopulations of the yellow-bellied toad ( Bombina variegata) using capture-recapture data. Combining the results of this study with another recent study, we found that a high dispersal rate, high fecundity, and a short lifespan are associated in metapopulations experiencing unpredictable environments. In contrast, a very low dispersal rate (close to zero), low fecundity and a long lifespan are associated in metapopulations occupying predictable environments. We discuss these results as well as their demographic and evolutionary consequences. [ABSTRACT FROM AUTHOR]

Weather fluctuations have been demonstrated to affect demographic traits in many species. In long-lived organisms, their impact on adult survival might be buffered by the evolution of traits that reduce variation in interannual adult survival. For example, skipping breeding is an effective behavioral mechanism that may limit yearly variation in adult survival when harsh weather conditions occur; however, this in turn would likely lead to strong variation in recruitment. Yet, only a few studies to date have examined the impact of weather variation on survival, recruitment and breeding probability simultaneously in different populations of the same species. To fill this gap, we studied the impact of spring temperatures and spring rainfall on survival, on reproductive skipping behavior and on recruitment in five populations of a long-lived amphibian, the yellow-bellied toad (Bombina variegata). Based on capture-recapture data, our findings demonstrate that survival depends on interactions between age, population and weather variation. Varying weather conditions in the spring result in strong variation in the survival of immature toads, whereas they have little effect on adult toads. Breeding probability depends on both the individual's previous reproductive status and on the weather conditions during the current breeding season, leading to high interannual variation in recruitment. Crucially, we found that the impact of weather variation on demographic traits is largely context dependent and may thus differ sharply between populations. Our results suggest that studies predicting the impact of climate change on population dynamics should be taken with caution when the relationship between climate and demographic traits is established using only one population or few populations. We therefore highly recommend further research that includes surveys replicated in a substantial number of populations to account for context-dependent variation in demographic processes. [ABSTRACT FROM AUTHOR]

Traditional farming landscape in western Europe is made of a complex mosaic of pastures, cultures, ponds and hedgerows connected with woods. Previous observations in the common frog species suggest that lowland populations are closely associated to wood cover and our aim was to test the validity of this assumption. We studied common frog occurrence and abundance in western central France (Deux-Sèvres department) close to the southern margin of lowland distribution. Our results pointed out that the proportion of woods surface around sampled areas (1 ha) was a critical determinant of common frog presence and abundance. Extensive farming, which maintains a mosaic of small woods, may provide a robust conservation tool for this species. [ABSTRACT FROM AUTHOR]

Abstract: Setting up effective conservation strategies requires the precise determination of the targeted species’ distribution area and, if possible, its local abundance. However, detection issues make these objectives complex for most vertebrates. The detection probability is usually <1 and is highly dependent on species phenology and other environmental variables. The aim of this study was to define an optimized survey protocol for the Mediterranean amphibian community, that is, to determine the most favorable periods and the most effective sampling techniques for detecting all species present on a site in a minimum number of field sessions and a minimum amount of prospecting effort. We visited 49 ponds located in the Languedoc region of southern France on four occasions between February and June 2011. Amphibians were detected using three methods: nighttime call count, nighttime visual encounter, and daytime netting. The detection nondetection data obtained was then modeled using site‐occupancy models. The detection probability of amphibians sharply differed between species, the survey method used and the date of the survey. These three covariates also interacted. Thus, a minimum of three visits spread over the breeding season, using a combination of all three survey methods, is needed to reach a 95% detection level for all species in the Mediterranean region. Synthesis and applications: detection nondetection surveys combined to site occupancy modeling approach are powerful methods that can be used to estimate the detection probability and to determine the prospecting effort necessary to assert that a species is absent from a site. [ABSTRACT FROM AUTHOR]

Relocations are increasingly popular among wildlife managers despite often low rates of relocation success in vertebrates. In this context, understanding the influence of extrinsic (e.g., relocation design, habitat characteristics) and intrinsic factors (e.g., age and sex) on demographic parameters, such as survival, that regulate the dynamics of relocated populations is critical to improve relocation protocols and better predict relocation success. We investigated survival in naturally established and relocated populations of yellow‐bellied toads (Bombina variegata), an amphibian that was nearly extinct in Belgium by the late 1980s. We quantified survival at three ontogenetic stages (juvenile, subadult, and adult) in the relocated population, the source population, and a control population. In the relocated population, we quantified survival in captive bred individuals and their locally born descendants. Then, using simulations, we examined how survival cost to relocation affects the self‐sustainability of the relocated population. We showed that survival at juvenile and subadult stages was relatively similar in all populations. In contrast, relocated adult survival was lower than adult survival in the source and control populations. Despite this, offspring of relocated animals (the next generation, regardless of life stage) survived at similar rates to individuals in the source and control populations. Simulations revealed that the relocated population was self‐sustaining under different scenarios and that the fate (e.g., stability or increase) of the simulated populations was highly dependent on the fecundity of relocated adults and their offspring. To summarize, our results indicate that survival in relocated individuals is lower than in non‐relocated individuals but that this cost (i.e., reduced survival) disappears in the second generation. A finer understanding of how relocation affects demographic processes is an important step in improving relocation success of amphibians and other animals. [ABSTRACT FROM AUTHOR]

Dispersal is a central mechanism in ecology and evolution. Dispersal evolution is driven by a trade-off between costs and benefits, which is influenced by interindividual variability and local environmental conditions (context-dependent dispersal). Many studies have investigated how dispersal decisions may be influenced by environmental factors, including density, predation and interspecific competition. Yet few have attempted to examine how habitat disturbance may affect the dispersal process in spatially structured populations. In early successional species, one might expect individuals to adjust their dispersal decisions based on two main factors that potentially have an influence on reproductive success: patch size and the level of patch disturbance. In this study, we examined how these two factors affect breeding success and dispersal decisions in an early successional amphibian, the yellow-bellied toad, Bombina variegata. To this end, we used capture–recapture data collected on a spatially structured population occupying 28 breeding patches. We took advantage of recent developments in multievent capture–recapture models to detect signs of context-dependent dispersal. The results revealed that the probability of successful reproduction and the number of newly metamorphosed individuals increased with both the size and the proportion of disturbance of a patch. In addition, our results showed that the factors affecting breeding success also influenced breeding dispersal probability. Large patch size negatively influenced emigration probability; in contrast, it positively influenced immigration probability. Equally, higher disturbance had a strong negative influence on emigration probability and slightly positively affected immigration probability. These findings strongly suggest that individuals make context-dependent dispersal decisions, adjusted to maximize future fitness prospects in a patch, allowing them to better cope with rapid changes in environmental conditions resulting from the ecological succession process. This opens new areas of potential research into the role of dispersal in organism specialization along an ecological succession gradient. Highlights • We studied breeding success and dispersal of an early successional amphibian. • Breeding success depended on patch size and disturbance. • Emigration and immigration probabilities depended on patch size and disturbance. • Context-dependent dispersal allows coping with rapid changes in patch conditions. [ABSTRACT FROM AUTHOR]