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Conservation practices in agricultural landscapes can greatly mitigate biodiversity loss. However, agricultural landscapes are embedded in complex, social-ecological systems and therefore require a strong social-ecological approach for effective conservation measures. The Galapagos Islands are globally recognized for their high levels of biodiversity. Nevertheless, in recent years, Galapagos landbirds have suffered rapid declines, specifically in the agricultural zone. Our study is the first to examine the farmers’ perception of landbirds in the agricultural zone of Santa Cruz, Galapagos Islands. We conducted semi-structured interviews with 38 farmers to characterize the relationship between farmers and landbirds including how landbirds affect farmers and farmers’ perceptions of landbirds. The interviewed farmers managed a diverse array of farm types including coffee in agroforestry settings (23.7%), small-scale fruit and vegetable (60.5%) and livestock production (15.8%). We found that 86.9% of farmers had a positive or neutral perception of birds despite 52.6% of farmers finding finches bothersome. The most common techniques farmers employed to deter birds were putting out food and water, using nets to protect seedbeds and crops and using protective tubes around young plants. Our results suggest a positive potential for future conservation work targeted on farmland biodiversity. Future conservation projects should also address disservices and the mitigation of crop raiding by landbirds, the uninformed use of pesticides and other pest issues such as ants and rats.

One of the principal drivers of biodiversity loss is habitat loss due to land conversion for agriculture. Understanding how agricultural landscapes can be more biodiverse is critical in devising a working lands conservation plan. For at least 20 years, some bird populations in the Galapagos have been in sharp decline, especially in the agricultural zone. Since 2010, we found that the relative abundance of ten out of eleven monitored landbird species has further decreased. We examined the existing habitat structures in the agricultural zone of Santa Cruz, historically established in former areas of native humid forest (Scalesia), and analyzed which structures associated with higher landbird diversity and abundance of four declining species. We conducted standardized point counts and surveyed surrounding vegetation during the breeding period. Landbird diversity was highest in forest and coffee sites and least diverse in pasture sites. Main predictors of higher landbird diversity were forest patch presence, increased abundance of native vegetation and lower elevations. Main predictors of higher landbird relative abundance were percentage of forest in the surrounding 200 m radius buffer and forest patch presence. Our results suggest that to increase the contribution of farmlands to landbird conservation during the reproductive period, habitat management efforts should be targeted at increasing forest patches and/or corridors, particularly within pasture farms. Nevertheless, to ensure sustainability of these measures, economic value to the considered farmlands needs to be secured, social perspectives incorporated and other important threats to landbirds assessed.

There is an increasing interest in air-lubrication systems for high-speed craft and the high potential for optimisation to decrease further skin-friction and consequently greenhouse gas emissions. In this paper the focus will be on a passive air-lubrication system, which does not require dedicated energy extensive compressor system to pump the air. A low-pressure zone is created behind an interceptor when the vessel reaches certain minimum speed. The low-pressure zone is connected to the atmosphere through small holes on the hull, an air chamber, and an air pipe to provide air beneath the hull behind the interceptor. By increasing the speed (above 11 knots) then the air starts spreading beneath the hull providing air lubrication, higher the speed, more air is streaming through the system. The authors are collaborating on a research project studying the air-lubrication system in detail. The investigation includes laboratory testing, full-scale observations, and trials as well as numerical analysis. Two case vessels already equipped with the air-lubrication system participate in the investigation. In this paper results and findings of first phase of the project are presented, including CFD analysis, laboratory test results of different configurations of the air lubrication system performed in a cavitation tunnel, as well as visual underwater observations in full-scale. CFD analysis show sensitivity of the system to interceptor geometry. Existing interceptor adds approximately 5% to the bare hull resistance. For the air lubrication system to be effective, it needs to provide savings above the required energy to overcome the additional resistance due to the interceptor. Therefore, optimisation of the interceptor geometry is also part of the current study.

Animal vocalizations may provide information about a sender’s condition or motivational state and, hence, mediate social interactions. In this study, we examined whether vocalizations of gray mouse lemurs (Microcebus murinus) emitted in aggressive contexts (grunts, tsaks) co-vary with physical condition, which would underly and indicate honest signaling. We recorded calls from captive individuals that were subjected to a caloric restricted (CR) or ad libitum (AL) diet, assuming that individuals on an ad libitum dietary regime were in better condition. We analyzed 828 grunts produced by seven CR and nine AL individuals and 270 tsaks by eight CR and five AL individuals. Grunts consisted of two separate elements, with the 1st element having more energy in higher frequencies than the 2nd element. Body mass correlated negatively with acoustic features of grunts, and heavier individuals produced lower-frequency grunts. Acoustic features of grunts did not differ between sexes. Acoustic features of tsaks were predicted by neither body mass nor sex. However, tsaks produced by AL individuals were noisier than those of CR individuals. Hence, manipulation of body condition via dietary regimes affected acoustic features of calls given during aggression in different ways: acoustic features of grunts varied according to the rule of acoustic allometry, and can be considered as honest signals. Acoustic features of tsaks, however, varied according to motivational structural rules. Longitudinal studies are now indicated to examine whether intra-individual changes in body mass are also reflected in the acoustic structure of calls, allowing callers to signal more flexible variation in condition.

The dependency of the friction factor on the flow direction was investigated experimentally in a milled scale model of an unlined rock blasted tunnel under pressurized flow conditions by reversing the flow direction. The experimental data were used to highlight the significance of anisotropic roughness structures and variations in the cross-sectional area on the flow resistance. It is hypothesized that local sudden expansions of the cross-sectional area, which are followed by gradual contractions, contribute significantly to the directional dependency of the friction factor due to potential flow separation. For the reversed case, i.e. when sudden large-scale contractions were followed by gradual expansions, 15% lower friction factors were observed. The results were also used to highlight the scale dependency of these topographical features, the dependency of the friction factor from the tunnel driving direction, and to show the need for the development of methods that can be used to parameterize the directional dependency of hydraulic roughness and friction factors.

Knowledge of the origin and spatial distribution of migratory bird contingents is essential information for the study and conservation of their populations. In short-distance migratory birds, their propensity to migrate has reduced over the past decades: more individuals remain year-round on the breeding grounds, and those that migrate winter at closer distance. To inform the management of these migratory populations and species subject to intensive hunting during the non-breeding season, we must document and understand how their migratory behaviours have changed over the past decades. Using ringing-recovery data spanning over the past 70 years (1950–2018), we updated knowledge on origins and within-France spatial distribution of five hunted European turdids migrating to/through France (common blackbird, fieldfare, song thrush, redwing and mistle thrush), and documented how these aspects have changed over time. Our results confirm that France hosts non-breeding birds from all Continental Europe. Partial and short-distance migratory populations from blackbird mainly come from western and central Europe and are strongly segregated in autumn and winter in France according to their origin. Surprisingly, our results relativize the presence of populations originating from Fennoscandia for the northernmost species (redwing and fieldfare), which present a slightly marked segregation. Finally, this study highlighted temporal changes in the migratory propensity for song thrush and mistle thrush, and modifications of the within-France spatial distribution for fieldfare, song thrush, and redwing. Through this new knowledge, we hope to provide a replicable method to characterize migratory populations’ distribution and bring elements to promote the differentiated management of hunted thrushes in Europe

On the journey to wintering sites, most migratory birds alternate between flights and stopovers, where they rest and refuel. In contrast to the time-minimization strategy commonly assumed to drive the pre-breeding migration, birds are rather expected to follow an energy minimization during post-breeding migration. It is the cumulative duration of flights and stopovers that determines the total energy requirements and duration of the journey. Since migrating birds actually spend most of the time at stopovers sites, selection to minimize the amount of energy or time spent on migration is likely to operate on the effectiveness of stopover rest and refueling. Here, we address the relative contribution of factors acting on departure decisions from a stopover site during the post-breeding migration in a long-distance migratory songbird. When capture probability is low, it is impossible to measure fattening over the entire duration of the stopover. To get around this limitation, we use time since arrival (TSA) as a proxy for the progressive temporal change occurring in the internal state of an individual (i.e. rest, physiological recovery, and fuel loading) during the stopover. We develop a capture-recapture model to address the respective effects of estimated TSA and of weather conditions on departure probability. Using a 20-year dataset for Sedge Warblers (Acrocephalus schoenobaenus), we show that TSA served as a surrogate of the most important information that birds use when deciding to depart from a stopover site, while low humidity and rising atmospheric pressure only slightly increase daily departure probability. Hence, a bird would resume migration mainly according to the time it had to rest and refuel, and then fine-tuning departure decision according to weather conditions. The generality of these results needs to be assessed by applying this modeling framework to other migratory species and at sites or times with greater weather variability., Au cours de leur voyage vers les sites d’hivernage, la plupart des oiseaux migrateurs alternent entre vols et haltes migratoires, où ils se reposent et se ravitaillent. Contrairement à la stratégie de minimization de la durée de la migration, communément associée à la migration prénuptiale, les oiseaux suivent plutôt une stratégie de minimization de l’énergie pendant la migration postnuptiale. C’est la durée cumulée des vols et des haltes qui détermine les besoins énergétiques totaux et la durée du voyage. Puisque les oiseaux migrateurs passent la plupart du temps de migration sur les sites de halte, le choix de minimizer la quantité d’énergie ou le temps consacré à la migration est très susceptible d’opérer sur l’efficacité du repos et du ravitaillement durant la halte. Nous nous penchons ici sur la contribution relative des facteurs agissant sur les décisions de départ d’un site de halte pendant la migration postnuptiale chez un passereau migrateur longue distance. Lorsque la probabilité de capture est faible, il est impossible de mesurer l’engraissement sur toute la durée de la halte. Pour contourner cette limitation, nous utilisons le temps depuis l’arrivée (TSA) comme un indicateur du changement temporel progressif qui se produit dans l’état interne d’un individu (c’est-à-dire le repos, la récupération physiologique et la quantité d’énergie accumulée) pendant la halte. Nous développons ici un modèle de capture–recapture pour estimer les effets respectifs du TSA estimé et des conditions météorologiques sur la probabilité de départ. À l’aide d’un jeu de données de plus de 20 ans sur les phragmites des joncs, nous montrons que le TSA constitue l’information la plus importante dans la décision de départ d’un site de halte, tandis qu’une faible humidité et une pression atmosphérique croissante n’augmentent que légèrement la probabilité de départ quotidienne. Par conséquent, un oiseau reprendrait sa migration principalement en fonction du temps dont il dispose pour se reposer et se ravitailler, puis affinerait sa décision de départ en fonction des conditions météorologiques. La généralité de ces résultats doit être évaluée en appliquant ce cadre de modélisation à d’autres espèces migratrices, ainsi qu’à des sites ou des périodes présentant une plus grande variabilité météorologique.

International audience; Zoonotic tick-borne diseases threat human and animal health. Understanding the role of hosts in the production of infected ticks in an epidemiological system is essential to be able to design effective measures to reduce the exposure of humans and animals to infectious tick bites. The reservoir host potential, i.e. number of infected ticks produced by a host species, depends on three components: tick production, realized reservoir competence and host density. The parameters and factors that determine the reservoir host potential need to be characterized to achieve a robust understanding of the dynamics of pathogen-tick-host systems, and thus to mitigate the acarological risk of emerging infections. Few studies have investigated the role of birds in the local spread of Lyme borreliosis Borrelia. Knowledge of the research effort on the reservoir host potential of birds in Lyme borreliosis Borrelia circulation is necessary to prioritize future research on this topic. We provide a systematic review of the research effort on components of the reservoir host potential of wild birds for Lyme borreliosis Borrelia circulation, and factors that modulate these components in the European epidemiological system. Our review of 242 selected publications showed that tick production has been 1.4 and 21 times more studied than realized reservoir competence and bird density respectively. Only one study achieved to characterize the global host reservoir potential of birds in a given epidemiological system. Investigated factors were mostly related to bird species identity, individual characteristics of birds and tick characteristics, whereas the influence of bird life-history traits have been largely under-investigated. Because simultaneous characterization of all parameters is notoriously complex, interdisciplinary research is needed to combine and accumulate independent field and laboratory investigations targeting each parameter on specific epidemiological system or host species. This can help gain an integrated appraisal of the functioning of the studied system at a local scale.

Water surface roughness in rivers and streams is mainly driven by flow, turbulence and riverbed conditions. Conversely, water surface roughness gives easy access to information about hydrodynamics ...

Myrhaug, D., & Henry, P.-Y. (2022). Assessment of random wave energy dissipation due to submerged aquatic plants in shallow water using deep water wave conditions. Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, 236(2), 519–524. https://doi.org/10.1177/14750902211039989 This article addresses the random wave energy dissipation due to submerged aquatic plants in shallow water based on deep water wave conditions including estimation of wave damping. The motivation is to provide a simple engineering tool suitable to use when assessing random wave damping due to small patches of plants in shallow water. Examples of application for typical field conditions are provided. The present method versus common practice is discussed. A possible application of the outcome of this study is that it can be used as a parameterization of wave energy dissipation due to vegetation patches of limited size in operational estuarine and coastal circulation models.

International audience; Wild and farmed animals are key elements of natural and managed ecosystems that deliver functions such as pollination, pest control and nutrient cycling within the broader roles they play in contributing to biodiversity and to every category of ecosystem services. They are subjected to global changes with a profound impact on the natural range and viability of animal species, the emergence and spatial distribution of pathogens, land use, ecosystem services and farming sustainability. We urgently need to improve our understanding of how animal populations can respond adaptively and therefore sustainably to these new selective pressures. In this context, we explored the common points between animal production science and animal ecology to identify promising avenues of synergy between communities through the transfer of concepts and/or methodologies, focusing on seven concepts that link both disciplines. Animal adaptability, animal diversity (both within and between species), selection, animal management, animal monitoring, agroecology and viability risks were identified as key concepts that should serve the cross-fertilization of both fields to improve ecosystem resilience and farming sustainability. The need for breaking down interdisciplinary barriers is illustrated by two representative examples: i) the circulation and reassortment of pathogens between wild and domestic animals and ii) the role of animals in nutrient cycles, i.e. recycling nitrogen, phosphorus and carbon through, for example, contribution to soil fertility and carbon sequestration. Our synthesis identifies the need for knowledge integration techniques supported by programmes and policy tools that reverse the fragmentation of animal research toward a unification into a single Animal Research Kinship, OneARK, which sets new objectives for future science policy. At the interface of animal ecology and animal production science, our article promotes an effective application of the agroecology concept to animals and the use of functional diversity to increase resilience in both wild and farmed systems. It also promotes the use of novel monitoring technologies to quantify animal welfare and factors affecting fitness. These measures are needed to evaluate viability risk, predict and potentially increase animal adaptability and improve the management of wild and farmed systems, thereby responding to an increasing demand of society for the development of a sustainable management of systems.

This Technical Note addresses the workflow for the production of hydraulic scale models using a Computer Numerically Controlled (CNC) production technique and investigates the possibilities to accurately reproduce topographical roughness features. Focusing on the construction of three scale models of unlined rock blasted tunnels, their accuracy is evaluated based on the comparison of differences between scaled prototype point clouds obtained by terrestrial laser scanning, spatially filtered meshes that served as input for the milling of the models, and digital twins of the constructed models that were created by Structure from Motion photogrammetry. The direct comparison between the point clouds and meshes as well as the comparison of derived statistical parameters show that the models could be reproduced with a high degree of accuracy. Observed deviations between the point clouds of the milled models and the milling meshes, as well as the scaled original point cloud, are identified and discussed in light of the production technique and the accuracy of the applied methods for the comparison.

Increasing urbanisation and human pressure on lands have huge impacts on biodiversity. Some species, known as “urban exploiters”, manage to expand in urban landscapes, relying on human resources. The House Sparrow (Passer domesticus) is the perfect example of a human-commensal species. Surprisingly, this urban exploiter has been declining all over Europe over the past decades. The proximate causes of this decline remain poorly understood. We particularly lack understanding about urban habitat characteristics that are particularly unfavourable for House Sparrows. In the present study, we analysed fine-scale habitat characteristics of House Sparrow population sizes and trends using a fifteen-year House Sparrow census (2003–2017) covering the urban diversity of Paris (nearly 200 census sites), one of the densest European cities. We documented for the first time the dramatic decline (−89%) of the species in Paris over the study period. The temporal decline over the whole city correlates with the concomitant increase in the number of breeding Sparrowhawks. We could not detect statistical influences of annual variations in weather conditions and pollution. The decline of House Sparrows is spatially heterogeneous. Indeed, site-scale analyses revealed sharpest declines at sites that initially hosted the largest numbers of sparrows, which are areas with a relatively high proportion of green spaces and new buildings. Further experimental studies are now needed to disentangle the exact impact of specific characteristics of the urban environment on House Sparrow populations.

On the journey to wintering sites, migratory birds usually alternate between flights and stopovers where they rest and refuel. Migration strategies are assumed to differ according to season: a time-minimization pre-breeding migration strategy towards breeding locations, and an energy-minimization post-breeding migration strategy to wintering ones. The duration of flights and stopovers determines the energy requirements and the total duration of the journey. Since migrating birds actually spend most of the time at stopovers, selection to minimize the amount of energy or time spent on migration is very likely to operate on the effectiveness of stopover rest and refueling. Here we address the relative contribution of factors to departure decisions from stopover sites during the post-breeding migration in a long-distance migratory songbird. When capture probability is low it is impossible to assess the variation in body condition over the entire duration of the stopover. To get around this, we use Time Since Arrival (TSA) as a proxy for the changes in the state of individuals during the stopover. We propose that TSA is an integrative proxy for resting, feeding and fattening efficiency. We develop a capture-recapture model to address the relationship between departure probability, estimated TSA, and weather conditions. Using a 20-year dataset from sedge warblers, we show that TSA has a larger effect on departure probability than weather conditions. Low humidity and an increase in atmospheric pressure in the days preceding departure are associated with higher departure probability, but these effects are smaller than that of TSA.

AIM: There is mounting evidence that climate warming can induce morphological changes locally, particularly size reduction. However, the direction of thermal stress may differ between climatic regions. We predicted that morphological response to temperature fluctuations should vary throughout species ranges, depending on the local climate. Hot temperature anomalies are expected to induce size reduction in hot regions where species live close to their upper thermal limit, whereas size stasis (or increase) would be expected in cold regions, where species live close to their lower thermal limit. LOCATION: France (204 sites). TIME PERIOD: 2000–2014 springs. MAJOR TAXA STUDIED: Songbird species (n = 9). METHODS: We tested whether the effect of temperature anomalies on juvenile body size varied along an 11 °C thermal gradient. RESULTS: In warmer springs, juveniles were larger overall at the coldest sites, but this effect decreased toward the hottest sites, becoming negative for two species. MAIN CONCLUSIONS: Warming should induce body size increases more frequently at the cold edge of species distribution ranges, and rather body size declines at the hot edg. The climate dependency of the effect of weather fluctuations on body size is still under‐acknowledged, and the pattern identified deserves to be investigated over broader climatic gradients and taxonomic coverage. Climate‐driven changes in body size are therefore not uniform across climatic regions and within species ranges.

Structure function analyses are increasingly used to investigate spatial correlation patterns of river bed roughness. However, traditional structure function analyses remain mostly qualitative as t...

International audience; The biodiversity crisis has led to a surge of interest in the theory and practice of biodiversity monitoring. Although guidelines for monitoring have been published since the 1920s, we know little on current practices in existing monitoring schemes.Based on metadata on 646 species and habitat monitoring schemes in 35 European countries, we developed indicators for sampling design, sampling effort, and data analysis to evaluate monitoring practices. We also evaluated how socio-economic factors such as starting year, funding source, motivation and geographic scope of monitoring affect these indicators.Sampling design scores varied by funding source and motivation in species monitoring and decreased with time in habitat monitoring. Sampling effort decreased with time in both species and habitat monitoring and varied by funding source and motivation in species monitoring.The frequency of using hypothesis-testing statistics was lower in species monitoring than in habitat monitoring and it varied with geographic scope in both types of monitoring. The perception of the minimum annual change detectable by schemes matched spatial sampling effort in species monitoring but was rarely estimated in habitat monitoring.Policy implications: Our study identifies promising developments but also options for improvement in sampling design and effort, and data analysis in biodiversity monitoring. Our indicators provide benchmarks to aid the identification of the strengths and weaknesses of individual monitoring schemes relative to the average of other schemes and to improve current practices, formulate best practices, standardize performance and integrate monitoring results.

The Authors appreciate the discussion and thank the Discussers for the extended validation of the Lagrangian drifter through a comparison of measured surface roughness with predictions using the an...

International audience; The survival cost of reproduction has been revealed in many free‐ranging vertebrates. However, recent studies on captive populations failed to detect this cost. Theoretically, this lack of survival/reproduction trade‐off is expected when resources are not limiting, but these studies may have failed to detect the cost, as they may not have fully accounted for potential confounding effects, in particular interindividual heterogeneity. Here, we investigated the effects of current and past reproductive effort on later survival in captive females of a small primate, the gray mouse lemur. Survival analyses showed no cost of reproduction in females; and the pattern was even in the opposite direction: the higher the reproductive effort, the higher the chances of survival until the next reproductive event. These conclusions hold even while accounting for interindividual heterogeneity. In agreement with aforementioned studies on captive vertebrates, these results remind us that reproduction is expected to be traded against body maintenance and the survival prospect only when resources are so limiting that they induce an allocation trade‐off. Thus, the cost of reproduction has a major extrinsic component driven by environmental conditions.

International audience; Urban landscapes are associated with abiotic and biotic environmental changes thatmay result in potential stressors for wild vertebrates. Urban exploiters have physiological,morphological, and behavioral adaptations to live in cities. However, there isincreasing evidence that urban exploiters themselves can suffer from urban conditions,especially during specific life‐history stages. We looked for a link between thedegree of urbanization and the level of developmental stress in an urban exploiter(the house sparrow, Passer domesticus), which has recently been declining in multipleEuropean cities (e.g., London, UK). Specifically, we conducted a large‐scale study andsampled juvenile sparrows in 11 urban and rural sites to evaluate their feather corticosterone(CORT) levels. We found that juvenile feather CORT levels were positivelycorrelated with the degree of urbanization, supporting the idea that developinghouse sparrows may suffer from urban environmental conditions. However, we didnot find any correlation between juvenile feather CORT levels and body size, mass,or body condition. This suggests either that the growth and condition of urban sparrowsare not impacted by elevated developmental CORT levels, or that urban sparrowsmay compensate for developmental constraints once they have left the nest.Although feather CORT levels were not correlated with baseline CORT levels, wefound that feather CORT levels were slightly and positively correlated with the CORTstress response in juveniles. This suggests that urban developmental conditions maypotentially have long‐lasting effects on stress physiology and stress sensitivity in thisurban exploiter.

SummaryThe Northern Silvery Grebe Podiceps juninensis is an aquatic bird species considered Vulnerable to extinction in Ecuador and Endangered in Colombia. Globally the species is considered Near Threatened. Herein we report recent changes in distribution and population trends for the subpopulation in the northern Andes (Ecuador, Colombia), which is small and isolated. The Northern Silvery Grebe has undergone two documented extirpations, and at least one colonisation event, over the last three decades. More than 90% of the subpopulation relies on two wetlands, La Mica and Colta lakes in Ecuador, with the latter facing an accelerated sedimentation process which jeopardizes the fate of the wetland, and the species, in the mid-term. The population of La Mica lost 80% of its birds in 2000 after the damming of the lake, but then remained stable over our census period (2004–2013). In contrast, the Colta population results from a recent colonisation in the early 2000s, and has experienced an exponential growth since then (annual population multiplication rate: 1.464). The growth of this population is so fast that it must include an important contribution of immigrants. The temporal coincidence between the drop in population size at lake La Mica and the colonisation of lake Colta suggests that the Colta population was founded by immigrants from La Mica. Finally, the absence of current reports of the species at wetlands in Colombia suggests that the species remains at very low numbers, bolstering the shrinkage in northern distribution.

Marine growth is a large technical, economic and environmental problem for almost all activities at sea. Circular cylinders being widely used in different types of offshore structures, this study focuses on the effects of different types of marine growth on cylinders׳ wake structure for low Re steady flows (2.16×10 3 Re 4 ). Qualitative results from wake visualisations and simple drag force measurements confirmed that soft and hard roughnesses have completely different effects on the cylinder hydrodynamics for the transitional subcritical regime, as soft fouling act as a passive flow separation control. This study highlights the changes on the cylinder hydrodynamics induced by a developing fouling community, going from small hard roughnesses to fully developed soft fouling.

Urban landscapes are associated with abiotic and biotic environmental changes that may result in potential stressors for wild vertebrates. Urban exploiters have physiological, morphological, and behavioral adaptations to live in cities. However, there is increasing evidence that urban exploiters themselves can suffer from urban conditions, especially during specific life‐history stages. We looked for a link between the degree of urbanization and the level of developmental stress in an urban exploiter (the house sparrow, Passer domesticus), which has recently been declining in multiple European cities (e.g., London, UK). Specifically, we conducted a large‐scale study and sampled juvenile sparrows in 11 urban and rural sites to evaluate their feather corticosterone (CORT) levels. We found that juvenile feather CORT levels were positively correlated with the degree of urbanization, supporting the idea that developing house sparrows may suffer from urban environmental conditions. However, we did not find any correlation between juvenile feather CORT levels and body size, mass, or body condition. This suggests either that the growth and condition of urban sparrows are not impacted by elevated developmental CORT levels, or that urban sparrows may compensate for developmental constraints once they have left the nest. Although feather CORT levels were not correlated with baseline CORT levels, we found that feather CORT levels were slightly and positively correlated with the CORT stress response in juveniles. This suggests that urban developmental conditions may potentially have long‐lasting effects on stress physiology and stress sensitivity in this urban exploiter.

International audience; The interactions between water, sediment and biology in fluvial systems are complex and driven by multiple forcing mechanisms across a range of spatial and temporal scales. In a changing climate, some meteorological drivers are expected to become more extreme with, for example, more prolonged droughts or more frequent flooding. Such environmental changes will potentially have significant consequences for the human populations and ecosystems that are dependent on riverscapes, but our understanding of fluvial system response to external drivers remains incomplete. As a consequence, many of the predictions of the effects of climate change have a large uncertainty that hampers effective management of fluvial environments. Amongst the array of methodological approaches available to scientists and engineers charged with improving that understanding, is physical modelling. Here, we review the role of physical modelling for understanding both biotic and abiotic processes and their interactions in fluvial systems. The approaches currently employed for scaling and representing fluvial processes in physical models are explored, from 1:1 experiments that reproduce processes at real-time or time scales of 10−1-100 years, to analogue models that compress spatial scales to simulate processes over time scales exceeding 102–103 years. An important gap in existing capabilities identified in this study is the representation of fluvial systems over time scales relevant for managing the immediate impacts of global climatic change; 101 – 102 years, the representation of variable forcing (e.g. storms), and the representation of biological processes. Research to fill this knowledge gap is proposed, including examples of how the time scale of study in directly scaled models could be extended and the time scale of landscape models could be compressed in the future, through the use of lightweight sediments, and innovative approaches for representing vegetation and biostabilisation in fluvial environments at condensed time scales, such as small-scale vegetation, plastic plants and polymers. It is argued that by improving physical modelling capabilities and coupling physical and numerical models, it should be possible to improve understanding of the complex interactions and processes induced by variable forcing within fluvial systems over a broader range of time scales. This will enable policymakers and environmental managers to help reduce and mitigate the risks associated with the impacts of climate change in rivers.

This paper presents results from experiments that were carried out to study the effect of porosity and grain orientation on flow resistance. Experiments were performed over three rough surfaces; a water-worked gravel-bed, its non-porous facsimile (cast-bed) and the rotated cast-bed (cast tiles rotated through 180°). The first two beds were used to isolate the influence of gravel-bed porosity on the bulk flow resistance and the rotated cast was used to study effect of the grain orientation on the flow resistance. The results showed that the rotated cast-bed exerted the highest flow resistance whereas the porous water-worked gravel-bed was, for comparable hydraulic boundary conditions, characterized by slightly higher flow resistance than its non-porous counterpart. The results from the bulk flow analysis were substantiated by a preliminary analysis of flow velocity data. Influence of Gravel-Bed Porosity and Grain Orientation on Bulk Flow Resistance © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

This paper presents preliminary results from laboratory experiments which were specifically designed to determine the flow resistance over a water-worked gravel-bed and its impermeable counterpart (cast-bed). The technique used to create the cast-bed is introduced, followed by the description of the experimental setup and the procedure to quantify flow resistance over both the water-worked and cast-bed. The influence of the grain orientation on flow resistance was investigated in an additional set of experiments by rotating the cast-bed through 180° in the flume. The main focus of the paper is on the comparison of the bulk flow characteristics for the three different cases for which the beds are characterized not only by the same characteristic grain-diameter but also by an identical surface structure. The obtained results show that the porous, non-porous bed and rotated bed result in different flow resistance and that both bed porosity and grainorientation have a significant effect on flow resistance. © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).

Some protected species have benefited from human activities to a point where they sometimes raise concerns. However, gaps in knowledge about their human-related behaviour hamper effective management decisions. We studied non-breeding common ravens Corvus corax that aggregated and predated livestock in the surroundings of a landfill. Combining several approaches, we first assessed the effectiveness of relocations at distances ranging from 20 to 240 km, and of one-time disturbance consisting in non-lethal shots performed at night roosts and at surrounding foraging areas during two consecutive evenings, in reducing ravens’ presence at the landfill. Then, we documented the spatial ecology of both relocated ravens and control ones (i.e. released in situ). Although the return probability widely varied with relocation distance and time after release, homing behaviour (87/102 relocated ravens marked with wing tags [85.3%] returned to the landfill in 3 years) prevented relocations from sustainably reducing the presence of ravens. Likewise, one-time disturbance only decreased ravens’ abundance during a few hours. These results could be related to the extensive movements of ravens equipped with GPS trackers. The total area occupied by control ravens reached 40,492 km2, i.e. 7.4% of the area of France and 21.7% of the French species distribution range. Individuals used smaller home ranges (min = 84; max = 1814 km2), consisting in a network of foraging areas and roosts that they visited. The daily and weekly turnover rates in the observed area of the landfill were high (on average 0.68 ± 0.2 and 0.36 ± 0.17, respectively) and the actual presence of ravens displayed strong seasonal variation. Hence, one-time/local management actions affected only a limited proportion of the population, partly explaining their small impact. Our study provides information needed to improve future management plans in a context of increasing ravens populations and conflicts with human activities. published

Physical models are a well-accepted tool in hydraulic engineering, allowing for the detailed characterisation of flow processes and the validation of structure designs with complex boundary conditions. The methods used to construct physical models typically produce a surface roughness which does not necessarily scale with the surface roughness of the prototype. In this context, this paper discusses novel construction methods allowing a detailed reproduction of roughness elements in scaled models, such as Computer Numerically Controlled (CNC) manufacturing techniques and bed casting techniques. In particular, the present paper details the protocols developed to mill out a correct representation of the complex rock-fractured geometry of a closed channel which was obtained from Terrestrial Laser Scanners. The novelty of this scaled model production is the implementation of optical accesses in a closed (pressurized) hydraulic model, to allow for Particle Image Velocimetry measurements with a minimum impact on the reproduced roughness elements. The effectiveness of this production protocol is discussed in the context of modelling the roughness effects on the flow regime. © The Authors, published by EDP Sciences, 2018. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (http://creativecommons.org/licenses/by/4.0/).

The western European populations of Northern Wheatear Oenanthe oenanthe have halved over the past two decades. In this context of increasingly fragmented populations, a key issue is to understand the role of immigration in the maintenance of remnant populations. We characterized the local survival, fecundity, recruitment and immigration rates of a small, geographically isolated, coastal French population during a period of population stability, while the regional population was rapidly decreasing (1991-1999). Annual local adult and juvenile survival rates were estimated with capture-resighting data at, respectively, 0.463 ± 0.052 (n = 157 adults) and 0.215 ± 0.054 (n = 363 nestlings). Only 2.1 immigrants joined the population per year (7.3% of all recruits). This annual immigration rate (0.039) is lower than all 14 available estimates for small to medium-sized birds. The local population growth rate depended equally on all demographic parameters, apart from a minor influence of the immigration rate. Within-site breeding dispersal dis- tances were low, and differed between sexes (78 ± 49 m for males, 259 ± 274 m for females). Juvenile and adult survival rates appeared lower than for populations of wheatears settled in high quality habitats, but this deficiency was com- pensated by high fecundity and the 2 annual immigrants. The small population size (22-27 pairs), extremely low immi- gration, and strong dependence on local recruits suggest that this population was demographically isolated on a patch of moderate habitat quality, with no chance of rescue by immigration in case of stochastic event. Indeed, this popula- tion went extinct in the 2000's, after a disturbance of unknown origin.

Plant-flow interactions are characterised by an assemblage of processes acting at different temporal and spatial scales. In order to mathematically characterise these interactions, such processes have to be parameterised given some simplifications. Typically, drag coefficients are derived from experiments to characterise the plant reconfiguration and wave energy dissipation processes. By reviewing the different plant drag coefficients C D valid in oscillatory flows, this study first highlights the lack of normalisation of the different existing C D formulations and identifies possibilities for a standardisation of the formulations for oscillatory and steady flows. Then, by taking into account the wave crest height distribution of a sea state condition, this study further develops a stochastic method to compute the expected wave induced forces on a plant in linear/nonlinear random waves plus current based on two different C D formulations for waves alone and waves plus current. This method improves the characterisation of the stochastic plant–flow interactions by allowing the calculation of expected values under different random wave plus currents conditions. Results are compared to a classic deterministic approach and some differences are identified, calling for further investigations against experimental datasets. Based on the appropriate C D formulations, this study finally revealed that wave nonlinearities have a significant effect on expected wave forces for a higher wave activity, and that in presence of an increasing current, the effect of wave nonlinearities decreases while the expected wave forces increase.

In urban environments, wild vertebrates have to adjust to new environmental challenges (e.g., modified resource availability, increased chemical, noise and light pollutions). However, while the pace of urbanization is constantly increasing, little is known about the ultimate consequences of urban life on the condition of free-living organisms during different life-history stages. In this study, we investigated the influence of urbanization on the condition and non-ornamental feather quality in a common wild bird species, the House sparrow ( Passer domesticus ). Using a national network of trained ringers, almost 600 juvenile (early post-fledging) and adult sparrows were captured at 30 sites that differ in urbanization rates. To specifically test whether urbanization differentially affect individuals during different parts of the life cycle, we used several proxies for the energetic and nutritional conditions experienced during (1) the developmental period (body size, juvenile feather quality), (2) at the time of capture (body condition), or (3) during the molting period (adult feather quality). Using this methodology, we showed for the first time that urbanization is associated with both reduced body size and feather quality in this urban-dweller species across a large geographical scale. Importantly, only tarsus length and juvenile plumage quality, both determined during development in the nest, were affected by the degree of urbanization. Conversely, body condition and plumage quality did not differ along the urbanization gradient in adults. Our results thus suggest that urban house sparrows could suffer from nutritional deficit during their development while such constraints disappear once the chicks have completed their growth.