Search

The marine realm suffers from cumulative causes of biodiversity erosion and world seabird community declined by 50 % since 1970. Seabirds routinely transgress regional and international boundaries and threat assessments should be performed at large spatial scales. We studied the demographic consequences of transnational Spanish longline fisheries bycatch on vulnerable Scopoli's shearwater (Calonectris diomedea) populations in the French Mediterranean. First, we assessed space use for 174 shearwaters breeding in the Calanques National Park (NP) using GPS-tracking between 2011 and 2022. By matching this information with a published bycatch risk map for Mediterranean Spain, we found that shearwaters largely overlapped with Spanish longline fisheries. Second, we calculated Spanish demersal longline bycatch on shearwater populations of Calanques and Port-Cros NPs, using bycatch reports, ring recoveries and ringing effort. Annually, Spanish demersal longline fisheries killed 5.3 birds (95 % CI = 0.4–14.2; 0.5 % of the population) from the Calanques NP and 8.1 birds (0.5–21.6; 2.6 % of the population) from Port-Cros NPs. Third, we assessed the demographic consequences of this bycatch using multi-event capture-recapture models and matrix population modeling based on long-term nest monitoring. Adult survival was low (0.84 to 0.92) relative to other Procellariiforms. Even though annual shearwater casualties on Spanish demersal longline seem modest, they may compromise the persistence of several French Scopoli's populations within 50 years. We demonstrate the importance of designing marine conservation at international scales for highly mobile species, to fully embrace the cumulative effects of marine anthropogenic threats on adult seabird survival, the main leverage effect for long-lived vulnerable populations. • Seabirds suffer from the transnational cumulative impacts of fisheries bycatch. • The French Scopoli's shearwater population largely overlaps with Spanish fisheries. • Demersal Spanish longliners kill up to 3 % of French colonies annually on average. • Spanish bycatch therefore accelerates French shearwater population decline. • Highly mobile species require an international approach to marine conservation. [ABSTRACT FROM AUTHOR]

Estimating demographic parameters is key for unraveling the mechanisms governing the population dynamics of species of conservation concern. Endangered green sea turtles navigate vast geographical ranges during their life cycle and face various pressures in coastal areas, especially during their juvenile life-stage. Here, we investigated survival, abundance, recruitment and emigration of juvenile green turtles on two developmental grounds in Martinique, French West Indies, using a capture-mark-recapture dataset of 658 captures over 10 years. We detected increasing abundances of green turtles, likely attributed to the continuous recruitment of new individuals, low mortality and low rate of emigration from these two developmental sites. Local recruitment slightly decreased with small turtle densities while emigration strongly increased with large turtle densities. These results associated with known food availability and size-dependent diet preference of local green turtles suggest that the expansion of invasive seagrass H. stipulacea may facilitate the settlement of small juveniles, however it also limits the capacity of seagrass beds to sustain large juveniles. Boat anchorage, pollution and H. stipulacea invasion reduced the availability of native seagrass species. This could intensify competition between large turtles, trigger earlier emigration, therefore modifying the structure of the green turtle population in Martinique. Measures to protect native seagrass beds are essential to maintain their capacity to sustain the entire green turtle developmental life-stage. This study will help to connect sea turtle life-stages and to inspire efficient regional conservation measures. Finally, our results will help to understand the demography of endangered megaherbivores in context of grazing areas degradation. • Juvenile green turtle survival, abundance, recruitment and emigration were estimated. • Emigration is density-dependent, and recruitment is likely driven by external factors. • Size-dependent diet and H. stipulacea invasion may explain the observed dynamics. • Seagrass protection and restoration is needed to protect juvenile foraging grounds. • Considering perturbation to grazing areas is key for megaherbivore conservation. [ABSTRACT FROM AUTHOR]

Aquatic wildlife is exposed through trophic transfer of hazardous substances to several threats inducing physiological impairments. We aimed at assessing the impact of contamination in one of the hot spots of pollution along Mediterranean coasts, the gulf of Gabes in Tunisia, on Common tern Sterna hirundo , a piscivorous top predator bird. Firstly, we compared the reproductive effort of breeding adults through clutch size distribution in three sites with different levels of pollution. Then, a battery of genotoxicity and oxidative stress biomarkers was carried out to assess physiological impairments in chicks. While defense mechanisms showed a depletion, lipid peroxidation and genotoxicity increased significantly according to pollution level. The multi-biomarker approach used here, discriminated chicks according to contamination degree of their nesting sites. Increases in genotoxicity and oxidative stress were correlated to a decrease in chick body mass known to lead to long-term impacts on juvenile survival and recruitment in birds. • Lipid peroxidation and genotoxicity measured in chicks increased with the pollution level around the nesting sites. • Chicks were discriminated according to their physiological status in a way reflecting chemical pollution gradient • The increase in genotoxicity and oxidative stress was correlated to a decrease in chick body mass. [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]

Abstract The conservation of grasslands is a concern worldwide as they are threatened by climate change and the expansion of intensive agricultural practices. The management of these areas must take into account the decisional process of habitat selection by individual organisms to identify potential ecological traps or underused habitats. Organisms that live in heterogeneous environments must select their breeding habitat based on cues that reflect habitat quality. In dynamic ecosystems such as grasslands, environmental cues used by individuals should show a strong temporal autocorrelation, such that their characteristics during breeding can be predicted earlier in the season. Our objective was to test if habitat features that explain grassland birds' distribution during the nesting and chick-rearing period could be predicted from the habitat features available on territory settlement. In western France, we analysed the relationships between the occurrence, richness and abundance of four passerine species, and vegetation structure and composition during chick-rearing period. We then analysed the temporal autocorrelation of vegetation features to determine whether the cues used during the settlement period reliably predicted the vegetation features encountered at later stages of breeding. We found that birds selected habitats characterized by a low cover of grasses, but did not respond to the physical structure of vegetation. The composition of vegetation was also the only variable that exhibited temporal autocorrelation over the course of the season, suggesting that individuals may rely on this feature to select optimal breeding habitats. Our results suggest that in dynamic environments, and in the absence of breeding experience or public information, animals can choose their breeding habitat based on a simple assessment of vegetation composition. A detailed knowledge of the underlying drivers of habitat selection is essential to manage habitats, identify potential ecological traps, and enhance the attractiveness of areas especially those under agri-environmental schemes. [ABSTRACT FROM AUTHOR]

In Europe, the abandonment of agricultural activities and traditional forest usages have led to forest spread, which eventually affects the population ecology of open habitat species. This is particularly apparent in the Mediterranean hinterland, which hosts many endemic and/or rare species. In this study we explored the effects of forest spread on the population dynamics of Paeonia officinalis , a long-lived perennial species protected in France. We also simulated the effects of different forest management regimes, by projecting the dynamics of populations under different sylvicultural cycle lengths. From 2003 to 2009, we monitored individual plants in four sites in Southern France, where each population occurs in a woodland and in an adjacent open habitat. We found that forest encroachment negatively impacted population dynamics, manifested by reduced reproduction and germination and a marked stasis of vegetative demographic stages. Using matrix models with demographic and environmental stochasticity, we showed that for two sites, populations were only viable in the open habitat but not in the woodland. In one site, populations were viable both habitats, whereas in one site, populations were non-viable in both habitats. Tree cuttings positively affected the four populations either by increasing population stochastic growth rate or by decreasing extinction rate. However, the effectiveness of forest management depended on local ecological conditions, such as the identity of the dominant tree species (evergreen vs deciduous) and sylvicultural system (coppice vs exotic plantation). Our study highlights the need for of tailor-made rather general management recommendations in perennial plant conservation. [ABSTRACT FROM AUTHOR]

Contamination of aquatic ecosystems is considered as one of the main threats to global freshwater biodiversity. Within the European Water Framework Directive (EU-WFD) a particular attention is dedicated to assess ecological risks of surface water contamination and mitigation of chemical pressures on aquatic ecosystems. In this work, we evaluated ecological risks of surface water contamination for fish populations in four EU-WFD rivers through an integrative approach investigating three Lines of Evidence (chemical contamination, biomarker responses as early warning signals of contamination impacting individuals and ecological analyses as an indicator of fish community disturbances). This work illustrates through 4 case studies the complementary role of biomarkers, chemical and ecological analyses which, used in combination, provide fundamental information to understand impacts of chemical pressures that can affect fish population dynamics. We discuss the limitations of this approach and future improvements needed within the EU-WFD to assess ecological risk of river contamination for fish populations. [ABSTRACT FROM AUTHOR]

The objective of this study is to examine the sudden drop in properties of aluminum, titanium and chromium thin films prepared by the glancing angle deposition method. The thin films were deposited by DC magnetron sputtering under identical deposition conditions. A substrate-holder with seven different orientations with respect to the target normal was used. The thickness and the column tilt angles (β) of the thin films were determined by scanning electron microscopy. The residual stress of the thin films was evaluated using the wafer curvature technique and calculated by the Stoney's formula. The thickness variation and column tilt angle versus the orientation of the substrate indicated that the critical point is around 60° for all metallic materials and a critical angle of 60° is also found for the residual stress. Simulations of the particles transport are compared to the experimental data and moderate the critical angles analyses. [ABSTRACT FROM AUTHOR]

Evidence is accumulating on the crucial role of spatial demographic processes, particularly immigration, in driving the viability of wild animal populations. However, the contribution of immigration is rarely accounted for when performing population viability analysis and evaluating the efficiency of conservation actions, which can lead to spurious inferences. Here we analysed a 24-year monitoring scheme conducted on the French population of Bonelli's eagle, a population considered as vulnerable and targeted by two recent conservation plans. This population is located at the northern range-margin of the species' range and has suffered a long-standing decline before recovering recently thanks to efficient conservation actions (mainly retrofitting of power lines). We combined all available demographic information sources into an Integrated Population Model (IPM) for quantifying the relative contribution of immigration and local demography to the overall population dynamics. Population projections derived from local demography strikingly differed from the observed population trajectory. Throughout the study period, a sustained immigration rate (0.108 ± 0.03 immigrant females per occupied territory each year) first prevented the population to go extinct and then supported the recovery. The number of immigrants was about 1.0–1.5 times higher than the number of local recruits and we found only a weak evidence for a reduction in this ratio as survival rates increased. The fact that local conservation actions drove the recovery in mitigating anthropogenic perturbations revealed that range-margin populations should not be systematically considered as sink populations. Instead, demographic surveys should be promoted to assess the relative contribution of immigration and local demography alongside species' range (from centre to periphery) so as to improve our understanding of spatial demographic processes and ensure conservation actions are implemented at an appropriate spatial scale. [ABSTRACT FROM AUTHOR]

As semi-natural grassland has a high level of biological diversity, understanding the effects of grazing and its variation over time is important in order to identify sustainable grazing practices. We measured temporal variation in Orthoptera abundance and spatial vegetation structure during seasonal grazing in an extensive sheep-farming system. We studied five grazed pasture areas (pre-grazing and post-grazing) and two adjacent ungrazed grasslands. We recorded the total abundance of Orthoptera and described the vegetation structure of 175 replicate plots (25 per pasture/grassland) during six field sampling sessions. We demonstrated that the impact of grazing on Orthoptera abundance is species-specific and greatly varies over the grazing season. The decrease of phytovolume is significant after 4–7 weeks of sheep grazing. Total Orthoptera abundance was higher in pre-grazed plots than in ungrazed plots, and higher in ungrazed plots than in post-grazed plots. These differences were particularly high during the peak of adult abundance. No difference in species richness was observed between grazing intensities. Total Orthoptera abundance positively correlated to phytovolume only when grazing pressure was high. However, the relationship between abundance and phytovolume differed between species. Extensive grazing by sheep tends to homogenize spatial vegetation structure and to temporarily reduce total Orthoptera abundance at pasture scale. However, rotational grazing allows spatial and temporal heterogeneity in vegetation structure to be maintained at farm scale, heterogeneity that is beneficial for Orthoptera. In contrast, absence of grazing has a negative impact on Orthoptera abundance as it favours the accumulation of litter, which is detrimental for a high proportion of xerothermophilic Orthoptera associated with bare ground and short vegetation. [ABSTRACT FROM AUTHOR]

Abstract: Among human activities, the effect of habitat management by grazing on population viability is ambiguous. Indeed, beneficial effects of grazing are expected by maintaining open meadows, but overgrazing is supposed to increase mortality by trampling. Grazing has been shown to negatively impact the survival of European pond turtle (Emys orbicularis) in the Camargue. Consequently, a new management plan was defined. We investigated the consequences of this management using capture–recapture methods to estimate variations of population sizes in this managed site and a control site over a 17 years period. Results show an increase of the number of adults and juveniles on the managed site after the management change. Our results suggest that improved water management with flooding in autumn provided better hibernation conditions, and that reduced grazing intensity in autumn/winter likely decreased the risk of trampling. Population size significantly increased in less than 4 years following the management change, probably by the relaxation of density-dependence. It is an original result for a long lived-species supposed to have an important time of resilience to perturbations. [Copyright &y& Elsevier]

Highlights: [•] We used tortoise repeated-count surveys and presence-only data at a landscape scale. [•] Observer experience and habitat openness slightly influenced detection probability. [•] Wildfires had cumulative effects, occurrence falling to 7% in areas burned 3 times. [•] Species occurrence was high in patchy landscapes and scrubs/herbaceous vegetation. [•] Species occurrence was low in extensive artificial areas, vineyards and arable lands. [Copyright &y& Elsevier]

Abstract: Ranunculus weyleri is a narrow endemic protected plant from Majorca Island. It is known from only five populations located in two mountain areas 48 km apart. Using demographic data collected from 2007 to 2010, we assessed the demographic status of two populations – font des Coloms (FC) and talaia Moreia (TM) – using Integral Projection Models (IPMs). We showed that none of the two populations were declining under a deterministic model. Population FC was stable (λ = 1.026, CI95% = 0.965–1.093), while population TM showed sign of demographic expansion (λ = 1.113, CI95% = 1.032–1.219). Plant survival, flowering probability and the mean number of seedlings per floral peduncle were lower in TM, whereas growth and the number of floral peduncles per reproductive plant were lower in FC. Elasticity analyses showed that management strategies increasing plant survival and growth would be the most efficient to increase λ for both populations. Herbivory pressure by goats has been shown to be high in TM, resulting in high predation rate on floral peduncles. Controlling goat pressure may thus represent a promising management option, provided that we can demonstrate a negative impact of herbivory by goats on survival and growth which are the most critical parts of the life cycle in this species. Meanwhile, initiating a long-term monitoring is of crucial importance to get more insights into the relationships between environmental variation, plant performance and population dynamics. [Copyright &y& Elsevier]

Abstract: Chromium thin films were sputter deposited implementing the GLancing Angle Deposition (GLAD) method, which is a thin film deposition technique where the incident vapor flux – composed of atoms and molecules from gas phase – strikes onto the substrate at tilted angles . Oriented chromium columns were produced with various column angles (from 0 to 60°) closely linked to the sputtering pressure and incidence angle . Three sputtering pressures of 0.11, 0.40 and 0.53Pa were used. Incidence angle of the sputtered particles was systematically changed from 0 to 80°. Tribological properties were investigated as a function of these operating parameters. Results reveal that the tribological behaviour is strongly correlated with the structure and especially the growth mechanism of the films, which are both linked with the operating sputtering parameters. Thus, at the lowest sputtering pressure (0.11Pa), gradual variations of the tribological properties and wettability are observed as a function of the incidence angle , which are interesting for tailoring surfaces displaying a gradient of wettability. In contrast, at higher sputtering pressures (), local variations of static friction coefficient, wettability and lateral contact stiffness are systematically observed as a function of the column angle —and then the incidence angle . Basically, these results enable to tailor tribological properties by tuning the incidence angle in order to control the transition from sticking to sliding in micro-gripping. [Copyright &y& Elsevier]

Abstract: Animal restocking is a widely used conservation tool to restore relict populations of endangered species. However, success of such operations is often low due to poor short-term survival and experimental evidence is required to improve restocking results. We tested the impact of different release conditions on survival and reproduction of captive bred common hamsters (Cricetus cricetus L. 1758), a highly endangered species in Western Europe. As predation plays a determinant role for released hamsters, especially during the first days after restocking, we performed two release experiments intending to reduce mortality: we tested (1) the efficiency of terrestrial predator proof electric fences and (2) the impact of improved shelter availability. We assessed both survival rate and reproductive success by radiotracking 70hamsters between release date and the end of their aboveground active period. Reducing contact between released animals and predators thanks to electric fences had a strong positive impact on hamsters’ survival and allowed them to have enough time to reproduce. It also appeared that release of hamsters was more efficient in wheat crop than in alfalfa. As expected, wheat harvest, inducing a sudden lack of shelter, negatively impacted restocking success. Finally, lifetime after release affected the number of litters per female and varied with individual characteristics: it decreased with burrow change frequency and was slightly lower for males. We conclude that electric fences associated with permanent well-developed vegetative cover like unharvested wheat seem to be suitable for releasing hamsters. [Copyright &y& Elsevier]

• Land-use intensity affected rare segetal species. • Field edges hosted more segetal species than inner-field. • This difference significantly increased with land-use intensity. • Application of herbicides was the farming practice most detrimental to segetal species. • Species diversity was better explained by historic than current farming practices. Populations of segetal species are facing sharp declines in Europe due to agricultural intensification. To better conserve them, it is important to assess the effect of intensification in extensive mixed crop-livestock systems, which are considered hotspots for segetal species. The aim of this study was to evaluate how certain key farming practices and land-use intensity affect the composition, species richness and abundance of segetal species, taking into account spatial heterogeneity within the studied fields. To do this, we sampled 94 winter cereal fields - 41 farmed organically and 53 farmed conventionally - along a gradient of land-use intensity. At field scale, we found that both the species richness and the abundance of segetal taxa decreased with an increase in land-use intensity. The results also showed significant differences in segetal taxa composition, species richness and abundance between the edges and the inner-fields location and these differences significantly increased with land-use intensity. The species richness and abundance of both common and threatened segetal taxa were significantly higher at the edges of fields than within them. Herbicide treatments had a significant negative impact on segetal taxa species richness and abundance, while mechanical weeding had a positive impact on abundance. Nitrogen inputs had a significant detrimental effect only on the abundance of common segetal taxa. Crop seed origin and the ratio of cereal crops in the rotational cycle had no effect on segetal taxa species richness and abundance. Despite these impacts, we found that segetal species richness and abundance were better explained by farm identity (random factor) than by current management (fixed factors). Variation in segetal species richness and abundance between fields of the same farm and between farms reflect the long-term effects of farming practices and the history of seed transfer between farms more than by current management practices. In our study area, the production of cereals is destined for the consumption of the farm's sheep and the fact the cereals are not marketed makes it possible to tolerate the presence of segetal species in higher proportions than in intensive farming systems. [ABSTRACT FROM AUTHOR]

Abstract Nanostructured columnar titanium nitride (TiN) thin films were produced by oblique angle deposition using reactive magnetron sputtering. The influence of the angular distribution of the incoming particle flux on the resulting film morphology (column tilt angle, porosity, surface roughness) was studied by varying the inclination angle α of the substrate at two different working pressures, 0.3 and 0.5 Pa. The microstructural features and columns tilt angles β exp determined experimentally were compared to those simulated from two kinetic Monte Carlo (KMC) models. With increasing pressure, the TiN columns were found to be less defined but no significant changes in β exp were revealed. Both KMC models satisfactorily reproduced the experimental findings, the agreement being closer at 0.5 Pa. The evolution of β angle is also discussed with respect to the resulting incidence angle θ res of the incoming flux, this latter quantity accounting for the local incidence angle of individual particles, which may greatly differ from the geometrical angle α, especially at high working pressure due to the incoming particle – gas collisions. Crossover phenomena between the 0.3 and 0.5 Pa series were revealed from the evolution of the film resistivity, as well as simulated layer density and surface roughness versus α angle. Highlights • Understanding of column development is achieved for TiN films by combining thin film deposition and computational modelling at different pressures • The particle flux angular distribution reaching the substrate is the key parameter dictating growth morphology and column tilt angle β • TiN columns appear less tilted with increasing pressure for substrate tilt angles α ≥ 35° • Saturation of column tilt angle β around 25–30° is observed for α ≥ 65° due to the broadening of the angular distribution • Crossover phenomena of the layer density, surface roughness and resistivity versus angle α are revealed between 0.3 and 0.5 Pa Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Population monitoring traditionally relies on population counts, accounting or not for the issue of detectability. However, this approach does not permit to go into details on demographic processes. Therefore, Capture-Recapture (CR) surveys have become popular tools for scientists and practitioners willing to measure survival response to environmental change or conservation actions. However, CR surveys are expensive and their design is often driven by the available resources, without estimation about the level of precision they provide for detecting changes in survival, despite optimising resource allocation in wildlife monitoring is increasingly important. Investigating how CR surveys could be optimised by manipulating resource allocation among different design components is therefore critically needed. We have conducted a simulation experiment exploring the statistical power of a wide range of CR survey designs to detect changes in the survival rate of birds. CR surveys differ in terms of number of breeding pairs monitored, number of offspring and adults marked, resighting effort and survey duration. We compared open-nest (ON) and nest-box (NB) monitoring types, using medium- and long-lived model species. Increasing survey duration and number of pairs monitored increased statistical power. Long survey duration can provide accurate estimations for long-lived birds even for small population size (15 pairs). A cost-benefit analysis revealed that for long-lived ON species, ringing as many chicks as possible appears as the most effective survey component, unless a technique for capturing breeding birds at low cost is available to compensate for reduced local recruitment. For medium-lived NB species, focusing the NB rounds at a period that maximises the chance to capture breeding females inside nest-boxes is more rewarding than ringing all chicks. We show that integrating economic costs is crucial when designing CR surveys and discuss ways to improve efficiency by reducing duration to a time scale compatible with management and conservation issues. [ABSTRACT FROM AUTHOR]

Highlights: [•] We compared IUCN expert-based map of corncrake range and modelled distribution. [•] A sampling bias correction was applied to build an accurate distribution model. [•] The modelled distribution was surprisingly close to the expert-based assessment. [•] Model predictions are significantly correlated with species abundance per country. [Copyright &y& Elsevier]

Environmental impact assessments (EIAs) of windfarms require counting bat and bird carcasses around turbines to assess the number of individuals killed by collision or barotrauma. In order to accurately estimate mortality from carcass counts, most studies correct mortality by the probability of carcass removal between fatality searches, data that is obtained through persistence trials. However, there is currently no consensus on persistence trial design and estimation methodology. This study aimed to assess the sensitivity of several estimators employed during EIAs to collect persistence data. To this end, the persistence time of 266 carcasses was surveyed continuously using camera traps. This continuous observation data was resampled to generate virtual datasets collected using different survey intervals. Several estimators were then used to estimate mortality from a subsample of carcasses for each carcass survey interval. Mortality estimates obtained by the different estimators were very similar when persistence was observed continuously. However, differences between estimators emerged when persistence survey intervals widened, and even more so when fatality searches were conducted less frequently. The GenEst estimator seemed to produce less biased and more accurate mortality estimates compared to other estimators frequently used for EIAs. Based on these findings, we recommend limiting search intervals during persistence surveys as much as possible. If persistence time is low, we also recommend increasing fatality search frequency. For estimators using mean persistence time, the latter should be calculated using the median time between the last observation of the carcass and its first absence. • Carcass persistence monitoring design affects mortality estimates. • Mortality estimators have varying sensitivity and accuracy. • GenEst provides the most accurate estimates of persistence probability. • Surveys during persistence trials should be carried out as frequently as possible. • The median between the last presence and first absence should be used. [ABSTRACT FROM AUTHOR]

Environmental DNA (eDNA) analysis allows efficient surveys of freshwater species and is being increasingly used. However, because different authors use different methods, eDNA data cannot easily be summarised for a global overview. One promising approach is to standardise methods for long-term monitoring. Standardised eDNA metabarcoding methods have been implemented in France for an elusive group: freshwater bivalves. All French bivalve species can be detected and identified at each sampling site. Here, we analyse this comprehensive dataset (280 sites across all France; 40 species) to investigate detection probabilities, infer species distributions and reassess conservation status, and finally examine community patterns (richness) and their determinants. Our method gave over 95 % probability of detection for most species. Species distributions inferred from eDNA sampling were compared with currently known distributions. Four invasive species and one species of conservation concern were found outside their known range. Others were found in a surprisingly small number of localities, although they are currently thought to be widespread and not of conservation concern. Indeed, the databases currently used to determine conservation status are biased by the inclusion of old data, mainly based on shell records only, and may include misidentified species. The main drivers of species richness were latitude and distance from the spring. Co-occurrence of species was investigated for the first time. The results highlight the valuable data that eDNA analysis can provide when used on a large scale, for monitoring and ecological studies, as well as providing improved species distributions, which are essential for conservation policymaking. [Display omitted] • An extensive eDNA survey (260 sites) of freshwater bivalves has been undertaken • We study detection probabilities, current distributions and drivers of biodiversity patterns • The conservation status of some species is reassessed • The use of large-scale eDNA monitoring provides important guidelines for conservation policy [ABSTRACT FROM AUTHOR]

Large mammalian herbivores (LMH) shape vertebrate communities and structure food webs in many terrestrial ecosystems. However, the mechanisms that underlie the effects of LMH on other vertebrates are poorly understood. In France, domestic LMH have grazed alpine and mountain grasslands for thousands of years, profoundly influencing landscapes and wildlife. As LMH modify habitat structure, favour coprophagous insects and compete with herbivorous insects, the diet of insectivorous alpine birds may be deeply influenced by LMH grazing intensity. To investigate this, we sampled common insectivorous birds faeces (water pipit Anthus spinoletta and wheatear Oenanthe oenanthe) in sites characterized by different levels of grazing intensity by domestic and wild herbivores, in the open landscapes of the southern French Alps and the western Pyrenees. We used isotopic discrimination based on nitrogen stable isotope ratios as an indicator of the trophic level of the arthropods found in bird faeces. From isotopic ratios, we found that bird diets shift from mainly herbivorous arthropods at sites of low grazing intensity, to one mainly composed of other groups, such as predatory, detritivorous or coprophagous arthropods, at sites of higher grazing intensity. This result highlights the strong trophic link between LMH and insectivorous birds in open landscapes, contributing to a better understanding of interactions between domestic grazing, an activity that has historically modelled European landscapes, and biodiversity, with particular relevance for landscape management and bird conservation. • The diet of common insectivorous birds was inferred from stable isotopes ratios along a gradient of grazing pressure by large mammalian herbivores (LMH). • Along with an increase in LMH grazing pressure, birds diet shifted from herbivorous arthropods to arthropods with another diet. • This result highlights a strong trophic interaction mechanism between LMH and insectivorous birds in open landscapes. [ABSTRACT FROM AUTHOR]

Typically, analyze of capture–recapture data rely on standard protocols of individual detection. Encounters and reencounters of marked individuals are made during short sessions separated by constant time intervals. Very often, it can be reasonably assumed that the time between two sessions is the same for all individuals. However, in some studies, data is collected opportunistically within a season. This is often due to difficulties concerning fieldwork and/or a lack of people involved in data collection. It can also be intentionally chosen, for example, if collecting data within a season provides additional information on the status of the individual (e.g. whether it is a breeder or a non-breeder). When using capture–recapture data, opportunistic data has typically been analyzed by using discretize time intervals, to avoid taking into account the continuous-time processes of state and capture. In this study, we modeled the transition between a transient state (non-breeder) to one absorbing state (breeder) in a continuous process over time. A Poisson point process was used to model the capture data, allowing us to directly model the opportunistic data set. The main advantage of this new approach is that it allows a full use of opportunistic data – i.e. all available information can be used. As an illustrative working example, we applied the approach to investigate Alpine ibex ( Capra ibex ) reproduction over one year. We jointly estimated the following parameters: the breeding rate in the summer and the survival rate of the young from birth to the following spring. Our findings suggest that this modeling approach has the potential to open new perspectives in population ecology. [ABSTRACT FROM AUTHOR]

Rewilding has become a new paradigm to promote the natural recovery of many flagship species, including large carnivores. A better understanding of the factors that drive rewilding processes would allow predicting these in order to support them where desirable. Yet large-scale assessments of the factors that favor or limit mammal populations of conservation concern remain rare in Europe. This study sought to monitor changes in Eurasian otter (Lutra lutra) occupation over the years to identify the factors limiting its recolonization. To this end, we monitored otter signs and spraints over 1238 sampling sites in southwest France from 2003 to 2005 and then over 615 sites in 2011–2012. We modeled this dataset in a multi-season occupancy framework using biotic and abiotic covariates identified as potentially affecting otter detection, distribution and/or colonization rates. As otters are a cryptic and mobile mammal, we integrated detection probability and spatial autocorrelation (contagion) into the modeling design. Otter occurrence was detected at 31 % of the sites surveyed in 2003–2005 and 37 % of the sites surveyed in 2011–2012. Occupancy and colonization probabilities were strongly negatively correlated to the proportion of cultivated areas. Contagion covariates interacted strongly with other variables. These results suggest that, despite its recent colonization, the otter population in southwest France is still constrained in its expansion, notably by intensive agriculture. Natura 2000 schemes should incorporate rewilding approaches to further potentiate the colonization of this flagship species. Actions should focus on the conservation of natural riparian habitats and promote organic agriculture. • Otter populations recolonized rivers in southwest France between 2003 and 2012. • Occupancy and colonization were both constrained by areas of intensive agriculture. • Connection with otter-occupied catchments interacted strongly with other variables. • Otter detection varied between years, observers, stream width and human density. [ABSTRACT FROM AUTHOR]

In a context of increasing concern for biodiversity conservation but decreasing resources devoted to species management, measuring the impact of actions is critically needed so as to optimise conservation practices. Long-term longitudinal data collected on marked individuals allow for an assessment of the demographic response of a population to conservation actions while accounting for potential confounding factors. This study focused on the recovery of a geographically-isolated population of the endangered Egyptian vulture in south-eastern France, which experienced food shortages induced by major changes in habitat and sanitary legislation limiting the abandonment of dead animals in the field. The survival rates and population dynamics of the Egyptian vulture were computed, following the implementation of supplementary feeding stations, while accounting for the potential variation in environmental conditions on wintering grounds, reproduction and immigration. An integrated population model (IPM) was used to combine capture–resighting data with recoveries of dead birds, breeding surveys and counts of territorial pairs over a 16-year period. Results showed that the implementation of vulture restaurants improved the local survival rates and successfully stabilised the local demography of Egyptian vultures; this despite a reduction in average fecundity due to compensatory density feedback. Moreover, throughout the study period, about two thirds of the new recruits into the breeding population were immigrants, suggesting immigration constantly sustained the Egyptian vulture population in south-eastern France. However, we did not detect any effect of vulture restaurants on the immigration rate, indicating that the improvement of local survival by vulture restaurants remained the main driver of the positive shift in the population dynamics. This study highlights the positive impact of vulture restaurants on Egyptian vulture population restoration by compensating for natural food limitations. It also points out the methodological importance of estimating immigration for understanding population dynamics and that large-scale monitoring and internationally-concerted conservation should be promoted. [ABSTRACT FROM AUTHOR]

As freshwater habitats are among the most endangered, there is an urgent need to identify critical areas for conservation, especially those that are home to endangered species. The Pyrenean desman ( Galemys pyrenaicus ) is a semi-aquatic mammal whose basic ecological requirements are largely unknown, hindering adequate conservation planning even though it is considered as a threatened species. Species distribution modelling is challenging for freshwater species. Indeed, the complexity of aquatic ecosystems (e.g., linear and hierarchical ordering) must be taken into account as well as imperfect sampling. High-quality and relevant hydrological descriptors should also be used. To understand the influence of environmental covariates on the occupancy and detection of the Pyrenean desman, we combine both a robust sign-survey data set (i.e. with genetic validation ensuring true presence information) and a hydrological model to simulate the flow regime across a whole catchment. Markovian site-occupancy analysis, taking into account sign detection and based on spatially adjacent replicates, indicated a positive influence of heterogeneity of substrate and shelters, and a negative influence of flow variability on Pyrenean desman detection. This valuable information should help to improve monitoring programs for this endangered species. Our results also highlighted a spatially clustered distribution and a positive influence of stream flow and number of tributaries on occupancy. Hence, modifications of flow regime (e.g. hydropower production, irrigation, climate change) and habitat fragmentation appear to be major threats for this species, altering the connectivity between tributaries and the mainstream river as well as between adjacent sub-catchments. [ABSTRACT FROM AUTHOR]

Each year, millions of Palearctic waterbirds migrate between Eurasia and the wintering wetlands of the Sahel-Sahara region. International censuses show these populations are declining. Although hunting is recognised as the second cause of decline after habitat degradation along flyways, waterbird harvesting in the African wintering region remains overlooked. To fill this information gap, we conducted a hunting survey in the seven main Sahel-Saharan wetlands during the wintering season. Based on a socioeconomic, knowledge and off-take questionnaire, we estimated an annual harvesting level proxy per respondent. The results indicated that waterbird harvesting is a widespread practice in the research areas. Based on site, harvesting occurred from opportunistic and food off-take to specialised and commercial hunting. Rallidae and Anatidae were the targeted families, and Afrotropical species were more hunted than Palearctic species. Moreover, most of the targeted species had a "least concern" status in the IUCN red list of threatened species. Despite the high harvesting levels of the Malian and Egyptian sites, the total off-take seemed to occur at a lower level than at sites in Europe. This first survey conducted on this scale underlined that migratory waterbirds represent only a limited part of the food or income of the Sahel-Saharan human population. In order to secure both sustainable harvesting and environmental justice, international conservation efforts at the flyway level should implement a meaningful integration of Sahel-Saharan population cultural and subsistence needs and should engage all countries in a collaborative conservation and management approach across the entire migratory range. • Palearctic migratory waterbirds decline without knowing the hunting pressure in Sahel. • We conducted a survey in the seven main Sahel-Saharan wintering wetlands. • Most of the harvested species were not Palearctic and/or were of least concern for the IUCN. • Off-takes in wintering wetlands were mostly for local subsistence and selling. • Africa is not a flyway to hell for Palearctic migratory waterbirds. [ABSTRACT FROM AUTHOR]