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Accurate heritability estimates for fitness-related traits are required to predict an organism's ability to respond to global change. Heritability estimates are theoretically expected to be inflated if, due to limited dispersal, individuals that share genes are also likely to share similar environments. However, if relatives occupy similar environments due, at least partly, to genetic variation for habitat selection, then accounting for environmental similarity in quantitative genetic models may result in diminished heritability estimates in wild populations. This potential issue has been pointed out in the literature, but has not been evaluated by empirical studies. Here, we investigate whether environmental similarity among individuals can be partly explained by genetic variation for habitat selection, and how this link potentially blurs estimates for heritability in fitness-related traits. Using intensive GPS monitoring, we quantified home-range habitat composition for 293 roe deer inhabiting a heterogeneous landscape to assess environmental similarity. To investigate if environmental similarity might harbour genetic variation, we combined genome-wide data in a quantitative genetic framework to evaluate genetic variation for home-range habitat composition, which is partly the result of habitat selection at settlement. Finally, we explored how environmental similarity affects heritability estimates for behaviours related to the risk avoidance-resource acquisition trade-off (i.e. being in open habitat and distance to roads) and proxies of individual performance (i.e. body mass and hind foot length). We found substantial heritability for home-range habitat composition, with estimates ranging from 0.40 (proportion of meadows) to 0.85 (proportion of refuge habitat). Accounting for similarity in habitat composition between relatives decreased the heritability estimates for both behavioural and morphological traits (reduction ranging from 55% to 100% and from 22% to 41% respectively). As a consequence, only half of these heritability estimates remained significantly different from zero. Our results show that similar genotypes occupy similar environments, which could lead to heritable variation being incorrectly attributed to environmental effects. To accurately distinguish the sources of phenotypic variation and predict the ability of organisms to respond to global change, it is necessary to develop quantitative genetic studies investigating the mechanisms underpinning environmental similarity among relatives.

International audience; We conducted a field experiment to evaluate the effectiveness of neighboring vegetation to protect cherry-wood (Prunus avium) saplings against roe deer browsing and rubbing, and determine whether this protection varies according to the attractiveness of–and the physical barrier provided by–a variety of nurse shrubs. Our results show that nurse shrubs may delay roe deer browsing and rubbing on highly attractive cherry-wood saplings, even in a situation of high deer density. The most obstructing shrubs at roe deer knee to shoulder height (Populus x canescens and Cytisus scoparius) appeared to be efficient barriers, whereas the spiny shrub (Elaeagnus angustifolia) did not protect saplings more efficiently than thornless species. Yet, obstruction appeared to be less effective against browsing when the nurse species was itself browsed (Cornus sanguinea and Alnus cordata). Since roe deer may help to reduce plantation cleaning through the control of the shrub layer, especially brambles, we argue that natural methods of protection using surrounding vegetation should represent an economic and sustainable alternative to artificial protection of saplings.

Les modèles à équations structurelles représentent des systèmes dont les composantes, décrites comme des variables latentes, sont indirectement mesurées par des bouquets de variables observées. On présente une méthodologie dans un cadre non-asymptotique pour sélectionner la structure des relations entre composantes (modèle relationnel) et les liens composantes-variables observées (modèle d'observation), avec un exemple sur des écosystèmes forestiers.

International audience; A Tree-related Microhabitat (TreM) is a distinct, well-delineated morphological singularity occurring on living or standing dead trees, which constitutes a crucial substrate or life site for various species. TreMs are widelyrecognized as key features for biodiversity. Current TreM typology identifies 47 TreM types according to their morphology and their associated taxa. In order to provide a range of resolutions and make the typology moreuser-friendly, these 47 TreM types have been pooled into 15 groups and seven forms. Depending on the accuracy required and the time available, a user can now choose to describe TreMs at resolution levels corresponding totype, group or form. Another way to more easily record TreMs during routine management work would be to use co-occurrence patterns to reduce the number of observed TreMs required. Based on a large international TreMdatabase (2052 plots; 70,958 individual trees; 78 tree species), we evaluated both the significance and the magnitude of TreM co-occurrence on living trees for 11 TreM groups. We highlighted 33 significant cooccurrencesfor broadleaves and nine for conifers. Bark loss, rot hole, crack and polypore had the highest number of positive co-occurrences (N = 8) with other TreMs on broadleaves; bark loss (N = 4) had the highest numberfor conifers. We found mutually exclusive occurrences only for conifers: Exposed Heartwood excluded both dendrotelm and sap run. Among the four variables we tested for their positive contribution to significant cooccurrences,tree diameter at breast height was the most consistent. Based on our results and practical considerations, we selected three TreM groups for broadleaves, and nine for conifers, and formed useful short lists toreduce the number of TreM groups to assess during routine forest management work in the field. In addition, detecting potential similarities or associations between TreMs has potential theoretical value, e.g. it may helpresearchers identify common factors favouring TreM formation or help managers select trees with multiple TreMs as candidates for retention.

International audience; Adult females and males live apart outside the mating period in many social vertebrates, but the causes of this phenomenon remain a matter of debate. Current prevailing hypotheses predict no sexual segregation outside the early period of maternal care in nearly monomorphic species such as the Pyrenean chamois (Rupicapra pyrenaica). We examined sexual segregation in a population of the species, using data collected over 143 consecutive months on groups’ location and composition, and extending statistical procedures introduced by Conradt (1998b) and Bonenfant et al. (2007). In addition, we analysed the social interactions recorded between group members. As expected, habitat segregation was low throughout the year, with a maximum during the early lactation period. However, social and spatial segregation was consistently high, contradicting the predictions of the current prevailing hypotheses, while suggesting social causes were predominant. The scarcity of social interactions outside the mating season makes unlikely the hypothesis that males segregate to improve their reproductive success. We rather suspect that higher social affinities within than between the two sexes are at work. However, this hypothesis alone is probably insufficient to account for spatial segregation. Our results should revive the debate regarding the causes of sexual segregation.

International audience; A Tree related Microhabitat (TreM) is a distinct, well-delineated morphological singularity occurring on living or standing dead trees. It constitutes a crucial substrate or life site for species. TreMs are widely recognized as key features for biodiversity. Since TreMs are not to be found on every tree, their spatial distribution within a forest may affect TreM associated communities related to dispersal capacities of some taxa. However, these spatial patterns are not well known, either in old-growth or in managed forests. We assessed the spatial distribution of eleven TreM groups in European beech-dominated forests both in forests that have not been harvested for at least 100 years and in forests still ongoing management today. We made the assumptions that (i) we can detect spatial patterns in unmanaged forests, (ii) tree-dbh (diameter at breast height) spatial distribution is the main driver of TreM spatial distribution and (iii) management affects these patterns. We did not highlight any consistent spatial pattern, neither in managed nor in old-growth forests. The effect of dbh on TreM occurrence depended on both TreM and forest status. Plot features matters for explaining the occurrence of most of the TreMs. Considering the 10,000 ha natural forest of Uholka (Ukraina) as a case study, we highlighted a significant spatial aggregation for crown deadwood within the whole forest, but we did not find aggregation for the other TreMs.

Among grapevine diseases affecting European vineyards, Flavescence dorée (FD) and Grapevine Trunk Diseases (GTD) are considered the most relevant challenges for viticulture because of the damage they cause to vineyards. Unmanned Aerial Vehicle (UAV) multispectral imagery could be a powerful tool for the automatic detection of symptomatic vines. However, one major difficulty is to discriminate different kinds of diseases leading to similar leaves discoloration as it is the case with FD and GTD for red vine cultivars. The objective of this paper is to evaluate the potentiality of UAV multispectral imagery to separate: symptomatic vines including FD and GTD (Esca and black dead arm) from asymptomatic vines (Case 1) and FD vines from GTD ones (Case 2). The study sites are localized in the Gaillac and Minervois wine production regions (south of France). A set of seven vineyards covering five different red cultivars was studied. Field work was carried out between August and September 2016. In total, 218 asymptomatic vines, 502 FD vines and 199 GTD vines were located with a centimetric precision GPS. UAV multispectral images were acquired with a MicaSense RedEdge® sensor and were processed to ultimately obtain surface reflectance mosaics at 0.10 m ground spatial resolution. In this study, the potentiality of 24 variables (5 spectral bands, 15 vegetation indices and 4 biophysical parameters) are tested. The vegetation indices are selected for their potentiality to detect abnormal vegetation behavior in relation to stress or diseases. Among the biophysical parameters selected, three are directly linked to the leaf pigments content (chlorophyll, carotenoid and anthocyanin). The first step consisted in evaluating the performance of the 24 variables to separate symptomatic vine vegetation (FD or/and GTD) from asymptomatic vine vegetation using the performance indicators from the Receiver Operator Characteristic (ROC) Curve method (i.e., Area Under Curve or AUC, sensibility and specificity). The second step consisted in mapping the symptomatic vines (FD and/or GTD) at the scale of the field using the optimal threshold resulting from the ROC curve. Ultimately, the error between the level of infection predicted by the selected variables (proportion of symptomatic pixels by vine) and observed in the field (proportion of symptomatic leaves by vine) is calculated. The same methodology is applied to the three levels of analysis: by vineyard, by cultivar (Gamay, Fer Servadou) and by berry color (all red cultivars). At the vineyard and cultivar levels, the best variables selected varies. The AUC of the best vegetation indices and biophysical parameters varies from 0.84 to 0.95 for Case 1 and 0.74 to 0.90 for Case 2. At the berry color level, no variable is efficient in discriminating FD vines from GTD ones (Case 2). For Case 1, the best vegetation indices and biophysical parameter are Red Green Index (RGI)/ Green-Red Vegetation Index (GRVI) (based on the green and red spectral bands) and Car (linked to carotenoid content). These variables are more effective in mapping vines with a level of infection greater than 50%. However, at the scale of the field, we observe misclassified pixels linked to the presence of mixed pixels (shade, bare soil, inter-row vegetation and vine vegetation) and other factors of abnormal coloration (e.g., apoplectic vines).

BACKGROUND The noctuid Helicoverpa armigera is one of the key cotton pests in the Old World. One possible pest regulation method may be the management of host crop in the landscapes. For polyphagous pests such as H. armigera, crop diversity and rotations can offer sequential and alternate resources that may enhance abundance. We explore the impact of landscape composition and host crop diversity on the abundance and natal host plant use of H. armigera in northern Benin. RESULTS Host plant diversity at the largest scale examined (500 m diameter) was positively correlated with H. armigera abundance. Host plant diversity and the cover of tomato crops were the most important variables in relation to high abundance of H. armigera. Host plant (cotton, maize, tomato, sorghum) proportions and C3 versus C4 plants did not consistently correlate positively with H. armigera abundance. Moth proportion derived from cotton-fed larvae was low, 15% in 2011 and 11% in 2012, and not significantly related to H. armigera abundance. CONCLUSION Cotton crop cover was not significantly related to H. armigera abundance and may be considered as a sink crop. Landscape composition and sequential availability of host plants should be considered as keys factors for further studies on H. armigera regulation. (Resume d'auteur)

International audience; Tree-related microhabitats (TreMs) are specific, well delineated above-ground tree morphological singularities occurring on living or standing dead trees. As essential elements for species to develop, feed, shelter or breed during at least part of their life cycle (1), TreMs are key features for many taxa and contribute in the complex network of forest resources for biodiversity. Large and broadleaved trees bear most of the TreMs within a forest stand (2). The spatial pattern of TreMs may therefore be similar to the spatial distribution of these trees. However, this logic is impaired by several processes. Firstly, TreM types are generated by a wide range of natural processes, from stochastic, abiotic events such as lightnings to deterministic, biotic events such as the excavation of a woodpecker breeding cavity. Secondly, forest management strongly impacts the distribution of TreMs. Indeed, management always reduces TreM diversity, alters the relative proportion the TreM types and often shrinks TreM density (3). Logging can also locally produce TreMs such as missing barks along the logging tracks. Furthermore, during tree marking before harvesting operations, forest managers impact on both the distribution of TreM bearing trees and the TreM types they bear. A better knowledge of spatial patterns of TreMs in old-growth forests would help us to promote more biodiversity-friendly forest management practices. We therefore explored spatial patterns of several TreM types in temperate old-growth forests and compared them with patterns in managed stands. In order to better understand the effects of TreM spatial patterns on forest biodiversity, we analyzed the response of TreM-associated saproxylic beetle assemblages to variations in spatial patterns of cavities or polypores. The first results of these studies will be presented in this talk. Finally, we discuss deemed consequences for conservation of TreM-associated taxa in managed forests.

International audience; Routine movements of large herbivores, often considered as ecosystem engineers, impact key ecological processes. Functional landscape connectivity for such species influences the spatial distribution of associated ecological services and disservices. We studied how spatio-temporal variation in the risk-resource trade-off, generated by fluctuations in human activities and environmental conditions, influences the routine movements of roe deer across a heterogeneous landscape, generating shifts in functional connectivity at daily and seasonal time scales. We used GPS locations of 172 adult roe deer and step selection functions to infer landscape connectivity. In particular, we assessed the influence of six habitat features on fine scale movements across four biological seasons and three daily periods, based on variations in the risk-resource trade-off. The influence of habitat features on roe deer movements was strongly dependent on proximity to refuge habitat, i.e. woodlands. Roe deer confined their movements to safe habitats during daytime and during the hunting season, when human activity is high. However, they exploited exposed open habitats more freely during night-time. Consequently, we observed marked temporal shifts in landscape connectivity, which was highest at night in summer and lowest during daytime in autumn. In particular, the onset of the autumn hunting season induced an abrupt decrease in landscape connectivity. Human disturbance had a strong impact on roe deer movements, generating pronounced spatio-temporal variation in landscape connectivity. However, high connectivity at night across all seasons implies that Europe's most abundant and widespread large herbivore potentially plays a key role in transporting ticks, seeds and nutrients among habitats.

International audience; The balance between resource acquisition and risk avoidance should vary according to personality type, with potential knock-on effects for fitness. Although previous studies have suggested a link between boldness and fitness components, little evidence is available on the behavioural mechanisms mediating this relationship in the wild. Because habitat use is the outcome of the trade-off between the costs and benefits associated with using each habitat type, we evaluated between-individual differences in habitat use of 64 GPS-collared female roe deer, Capreolus capreolus, using multinomial logit mixed models. To investigate whether deer differed in their habitat use tactics in relation to their personality type and their annual reproductive success, we assessed the link between individual habitat use patterns, boldness (measured as the strength of behavioural responsiveness to handling) and annual reproductive success (measured by the presence/absence of fawns at heel during autumn). Although daily and seasonal variations in the risk-resource landscapes clearly drove patterns of habitat use, individuals adopted contrasting habitat use tactics depending on their position along the shy-bold gradient and their reproductive status. Shy individuals occupied safer woodland more frequently, even at night when risk is lower. In contrast, bold individuals were better able to exploit rich open habitats. When this included mature autumn crops, these females weaned more offspring. Finally, irrespective of personality type, females that used meadows more often also achieved higher annual reproductive success. Overall, we demonstrate that individuals express divergent habitat use tactics as a function of their ability to avoid exposure to risk and their annual reproductive success. (C) 2018 The Association for the Study of Animal Behaviour.

National audience; Les tiques, dont Ixodes ricinus, espèce la plus répandue en Europe, sont vecteurs de nombreux agents pathogènes, protozoaires, bactéries ou virus, qui peuvent être responsables de maladies touchant l’Homme (Borreliose de Lyme) ou l’animal (babésiose bovine). En vue d’identifier les zones à risque vis-à-vis de ces maladies, il est important de connaître la distribution spatiale des tiques. Cette distribution dépend d’une part des conditions locales de température et d’humidité, d’autre part des mouvements des hôtes des tiques (Estrada-Peña, 2002). Les chevreuils sont notamment reconnus pour influencer fortement la densité de tiques (Ruiz-Fons et Gilbert 2010) et se déplacer sur de longues distances. Dans le cadre de l’estimation spatiale des risques, il est nécessaire de disposer d’un modèle de déplacement des hôtes en fonction des caractéristiques du paysage, dont le développement n’a pas été réalisé à ce jour. Dans un premier temps, une approche théorique a été privilégiée. Un modèle du paysage a été développé via une tesselation de Voronoï et un processus de marquage. Au sein de ce paysage modélisé, le mouvement du chevreuil est modélisé par des équations différentielles stochastiques. Ce mouvement se décompose donc en deux termes : un de dérive, qui dépend d’une fonction de potentiel reliée aux différents habitats qui composent le paysage, et un terme de diffusion. A partir d’une première fonction potentielle, il est donc possible de simuler le déplacement d’un individu dans un paysage modélisé. Les développements actuels visent dans un premier temps à tester différentes fonctions de potentiel en fonction de nos connaissances sur le comportement du chevreuil. L’étape suivante consistera à développer des méthodes d’inférence afin d’estimer les paramètres à partir de données simulées ou observées. Par la suite le prototype obtenu pourra être utilisé pour tester l’influence des caractéristiques du paysage sur le mouvement des chevreuils. Enfin, un couplage avec un modèle de dynamique de population de tiques (Hoch et al, 2010) fournira des aires de répartition simulées des vecteurs.

Diet and breeding performance show variations across species’ range and between different habitats. In the present paper, we report data on the diet and breeding performance of Golden Eagles Aquila chrysaetos monitored during a ten-year period in two semi-natural landscapes located at the eastern and western extremities of the Pyrenees mountain range. In the Mediterranean area of the Corbieres, the diet was dominated by the Rabbit Oryctolagus cuniculus (31.5% of the prey items). In the Atlantic area of the Basque Country, the diet was more diverse, with the highest proportion of intra-guild predation and the highest diet breadth ever recorded for the species (Levins index of diet breadth: 12.14 vs 6.81 in the Corbieres). The proportion of successful breeding attempts was significantly higher in the Corbieres (60%) than in the Basque Country (38.5%). The same was true for mean productivity, with 0.70 and 0.45 fledglings per territory and year, respectively. These differences were partly related to the excess of snow cover in April in the Basque Country. Our results provide an example of intra-population variability in a long-lived apex predator at the extremes of a geographical gradient involving climate and prey availability.; La dieta y el éxito reproductor muestra variabilidad a través de los rangos de distribución de las especies y entre hábitats. En este artículo informamos sobre la dieta y el éxito reproductor del águila real Aquila chrysaetos en un estudio de diez años en dos paisajes seminaturales localizados en los extremos oriental y occidental de los Pirineos. En el área mediterránea de las Corbières, la dieta de las águilas reales estuvo dominada por el conejo Oryctolagus cuniculus (31,5% de las presas). En el área atlántica del País Vasco, la dieta fue más diversa, con la mayor proporción de depredación intra-gremio y la mayor amplitud de dieta que se ha registrado previamente para la especie (índice de Levins para la amplitud de dieta: 12,14 vs 6,81 en las Corbières). La proporción de reproducciones exitosas fue significativamente mayor en las Corbières (60%) que en el País Vasco (38,5%). Lo mismo ocurrió con la productividad media, con 0,70 y 0,45 volantones por territorio y año, respectivamente. Estas diferencias fueron debidas en parte al exceso de cobertura de nieve en abril en el País Vasco. Nuestros resultados proporcionan un ejemplo de variabilidad intrapoblacional en un superdepredador de larga vida en los extremos de un gradiente geográfico que involucra cambios en la disponibilidad de presas y el clima.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE [Axe_IRSTEA]TETIS-ATTOS; Flavescence dorée is a grapevine disease affecting European vineyards which has severe economic consequences and containing its spread is therefore considered as a major challenge for viticulture. Flavescence dorée is subject to mandatory pest control including removal of the infected vines and, in this context, automatic detection of Flavescence dorée symptomatic vines by unmanned aerial vehicle (UAV) remote sensing could constitute a key diagnosis instrument for growers. The objective of this paper is to evaluate the feasibility of discriminating the Flavescence dorée symptoms in red and white cultivars from healthy vine vegetation using UAV multispectral imagery. Exhaustive ground truth data and UAV multispectral imagery (visible and near-infrared domain) have been acquired in September 2015 over four selected vineyards in Southwest France. Spectral signatures of healthy and symptomatic plants were studied with a set of 20 variables computed from the UAV images (spectral bands, vegetation indices and biophysical parameters) using univariate and multivariate classification approaches. Best results were achieved with red cultivars (both using univariate and multivariate approaches). For white cultivars, results were not satisfactory either for the univariate or the multivariate. Nevertheless, external accuracy assessment show that despite problems of Flavescence dorée and healthy pixel misclassification, an operational Flavescence dorée mapping technique using UAV-based imagery can still be proposed.

About predictions in spatial autoregressive models: optimal and almost optimal strategies. Spatial Economic Analysis. This paper addresses the problem of prediction in the spatial autoregressive (SAR) model for areal data, which is classically used in spatial econometrics. With kriging theory, prediction using the best linear unbiased predictors (BLUPs) is at the heart of the geostatistical literature. From a methodological point of view, we explore the limits of the extension of BLUP formulas in the context of SAR models for out-of-sample prediction simultaneously at several sites. We propose a more tractable ‘almost best’ alternative and clarify the relationship between the BLUP and a proper expectation–maximization (EM) algorithm predictor. From an empirical perspective, we present data-based simulations to compare the efficiency of classical formulas with the best and almost best predictions.

International audience; Fire is acknowledged to be a factor for explaining the disturbance of vegetation dynamics interacting with other environmental factors. In this study, the authors want to clarify the importance and the role of fire on the dynamics of savanna vegetation. The study area is the Marovoay watershed located on the north-west coast of Madagascar. In this site, burning herbaceous cover is the main practice in the extensive grazing system. They analyzed the relationship between two indicators, one related to vegetation activity changes and one about fire regime that results from a combination of fire frequency and seasonality. All indicators were measured between 2000 and 2007 using a time series of MODIS images. In this work, the authors implemented two approaches of spatial analysis. The first one analyzes the spatial structure of the residuals of a per-pixel non-spatial GLM model. In the second approach, a spatial GLM model is directly computed. In both approaches, the authors proposed two levels of stratification for the study area according to the spatial variations of the relationship established between vegetation activity changes and fire regime. The use of spatial statistical tools produced parsimonious models which they found to be consistent with expert knowledge. The authors demonstrated that a statistical analysis based on spatial GLM is able either to stratify an area when non ancillary data on land use exist or to validate an existing stratification.

Maintaining a land base that supports safe and realistic training operations is a significant challenge for military land managers which can be informed by frequent monitoring of land condition in relation to management practices. This study explores the relationship between fire and trends in tallgrass prairie vegetation at military and non -military sites in the Kansas Flint Hills. The response variable was the longterm linear trend (2001-2010) of surface greenness measured by MODIS NDVI using BFAST time series trend analysis. Explanatory variables included fire regime (frequency and seasonality) and spatial strata based on existing management unit boundaries. Several non-spatial generalized linear models (GLM) were computed to explain trends by fire regime and/or stratification. Spatialized versions of the GLMs were also constructed. For non-spatial models at the military site, fire regime explained little (4%) of the observed surface greenness trend compared to strata alone (7% - 26%). The non-spatial and spatial models for the non -military site performed better for each explanatory variable and combination tested with fire regime. Existing stratifications contained much of the spatial structure in model residuals. Fire had only a marginal effect on surface greenness trends at the military site despite the use of burning as a grassland management tool. Interestingly, fire explained more of the trend at the nonmilitary site and models including strata improved explanatory power. Analysis of spatial model predictors based on management unit stratification suggested ways to reduce the number of strata while achieving similar performance and may benefit managers of other public areas lacking sound data regarding land usage.

International audience; We consider the problem of estimating the number of species (denoted by S) of a biological community located in a region divided into n quadrats. To address this question, different hierarchical parametric approaches have been recently developed. Despite a detailed modeling of the underlying biological processes, they all have some limitations. Indeed, some assume that n is theoretically infinite; as a result, n and the sampling fraction are not a part of such models. Others require some prior information on S to be efficiently implemented. Our approach is more general in that it applies without limitation on the size of n, and it can be used in the presence, as well as in the absence, of prior information on S. Moreover, it can be viewed as an extension of the approach of Dorazio and Royle (2005, Journal of the American Statistical Association 100, 389–398) in that n is a part of the model and a prior distribution is placed on S. Despite serious computational difficulties, we have perfected an efficient Markov chain Monte Carlo algorithm, which allows us to obtain the Bayesian estimate of S. We illustrate our approach by estimating the number of species of a bird community located in a forest.

International audience; We studied the walking activity over the year of free-ranging adult red deer (Cervus elaphus) in a mountainous area with the aim of describing the dynamics of movement patterns at the individual level. We monitored the distance walked by two males and two females fitted with global positioning system collars to test the hypothesis that deer adopt behaviours to reduce costs of locomotion. We predicted that both sexes would travel less in winter when disadvantageous environmental conditions occurred. We also predicted that the males would (1) reduce their movement soon after the rut due to very high energy expenditure during the breeding season and (2) travel less than the females due to their larger body mass. As we expected, minimum walking activity occurred after the rut from November to February for the males and in late February for the females. The walking activity of males peaked during the rut whereas that of females decreased. But compared to males, females moved more both during winter and daylight hours. Although our study stems from just four individuals, these results and the methodology used can be inspirational for red deer research as well as for ungulate research in general.

International audience; In this study, we sought to understand how landscape structure affects roe deer movements within their home-range in a heterogeneous and fragmented agricultural system of south-western France. We analysed the movements of 20 roe deer fitted with GPS collars which recorded their locations every 2–6 h over several months (mean = 9 months). Based on empirical observations and previous studies of roe deer habitat use, we hypothesised that roe deer should avoid buildings and roads, move preferentially along valley bottoms and through the more wooded areas of the landscape. To test these hypotheses we paired each observed movement step with 10 random ones. Using conditional logistic regression, we modelled a step selection function, which represents the probability of selecting a given step as a function of these landscape variables. The selectedmodel indicated thatmovements were influenced by all the tested landscape features, but not always in the predicted direction: our results suggested that roe deer tend to avoid buildings, roads, valley bottoms and possibly the more wooded areas (although the latter result should be interpreted with caution, as it may be influenced by a bias in the rate of GPS fix acquisition in woods). The distances to buildings and to roads were the most influential variables in the model, suggesting that the avoidance of potential sources of disturbancemay be a key factor in determining ranging behaviour of roe deer in human dominated landscapes.

International audience; To determine the spatial resolution of Global Positioning System (GPS) receiver data, rigorous testing is essential. We tested performance of the Lotek 3300 GPS collar for medium-sized mammals (Lotek Engineering, Inc., Newmarket, ON, Canada). To mimic real wildlife monitoring situations, we performed both static (stationary receiver) and mobile tests, placing the receiver collar on a dog. We compared fix locations of the mobile receiver with the actual trajectory described by a portable Trimble high-precision GPS. We determined performance in relation to habitat type and leaf cover. Location error was habitat-dependent, with the best results in open habitat and much poorer ones in forest, particularly coniferous-dominated forest. For both static and mobile tests, location accuracy was higher when the number of satellites contacted was high and when the residual positional dilution of precision (PDOP) value was low. However, location error was highly variable, even for a given PDOP value and a given number of satellites contacted. Finally, mobile collars performed less well than their static counterparts, presumably because of frequent changes of GPS position and orientation.

Behavioural consistency is a key assumption when evaluating how between-individual differences in behaviour influence life history tactics. Hence, understanding how and why variation in behavioural repeatability occurs is crucial. While analyses of behavioural repeatability are common, few studies of wild populations have investigated variation in repeatability in relation to individual status (e.g. sex, age, condition) and over different timescales. Here, we aimed to fill this gap by assessing within-population variation in the repeatability of docility, as assessed by the individual's response to human handling, in a free-ranging population of European roe deer, Capreolus capreolus. Docility was an equally repeatable behaviour at both short- and long-term timescales, suggesting that this behavioural trait is stable across time. Repeatability did not differ markedly between age and sex categories but tended to be higher in juvenile males than in juvenile females. Finally, contrary to expectation, individual variation in the repeatability of docility was not correlated with individual body mass. Further studies are required to assess the life history consequences of the individual variation in docility we report here. (C) 2015 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

International audience; Vigilance in prey species can serve many purposes, including predator detection and monitoring other group members, and is generally thought to impose a cost due to reduced food intake. However, previous studies have shown that herbivores are able to reduce the foraging cost of vigilance by chewing their food during vigilance bouts (‘vigilance with chewing’, as compared to ‘vigilance without chewing’). How predation risk, food availability and competition affect both the functions and the foraging costs of vigilance remains an open question. We studied female eastern grey kangaroos, Macropus giganteus, during winter and summer, when available food supplies were poor and rich, respectively, to investigate how group size, distance to cover, proximity between foragers and food patch quality affected decisions of foraging female kangaroos to exhibit antipredator or social vigilance, distinguishing vigilance with and without chewing. The use of antipredator vigilance was mainly driven by the perception of predation risk, and antipredator vigilance without chewing decreased with increased group size whereas antipredator vigilance with chewing increased nonlinearly with group size in winter. Distance to cover affected both forms of antipredator vigilance in summer only but there was no effect of nearest-neighbour distance. Social vigilance was affected positively by group size, and distance between foragers affected social vigilance without chewing positively, particularly in winter, and social vigilance with chewing negatively. Finally, patch quality increased the use of social vigilance with chewing in both seasons and decreased the use of antipredator vigilance with chewing in winter. This study provides new information on how animals make decisions about the functions and foraging costs of vigilance and allows a better understanding of how social foragers respond to an ever-changing environment.

SUMMARY This paper presents some statistical models and estimation procedures when the explanatory variables are functions. We put the stress on the fact that regularization techniques are needed in order to get stable and reliable estimations. Then, an application in remote sensing in presented. It shows the potential of these kind of models to handle real life problems. Copyright # 2005 John Wiley & Sons, Ltd.

Summary 1. The risk of pest damage in forest monocultures is a growing concern as the area of plantation forest expands world-wide and sustainable management is becoming a general goal. Numerous studies have demonstrated that pest insects are less abundant in more diverse agroecosystems, but limited experimental evidence exists for a similar relationship in forestry. Because plantation forests are usually mosaics of single-species stands, the aim of this study was to test the effect of forest diversity at a landscape level on pest insect infestations. 2. Within a stand of maritime pine, trees attacked by the stem borer Dioryctria sylvestrella showed no spatial aggregation and clusters of 66 trees proved to be an optimal sampling unit for determining overall percentage infestation. 3. The spatial distribution of stem borer infestation levels was examined in three maritime pine stands bordered by mixed-species stands of broad-leaved trees, and overall infestation levels compared between four such maritime pine stands and four other maritime pine stands of the same structure but far from any broad-leaved stands. 4. The percentage of trees infested was significantly lower in the pine stands bordered by broad-leaved stands than in the pine stands surrounded by other pine stands, and in the former, stem borer infestation showed a significant logistic increase with distance from the stand edge. This could be due to effects of resource concentration or natural enemy attack, both of which are discussed. 5. These results suggest that the conservation or restoration of non-productive mixed-species stands adjacent to intensively managed plantations is a useful preventive method for pest management in forest monocultures.

Atteindre l’objectif affiché de réduction du niveau d’usage de produits phytosanitaires tout en maintenant les niveaux de production des cultures implique la mise en place de stratégies de protection des cultures alternatives à la lutte chimique. L’adoption de pratiques plus favorables à la biodiversité dans les agroécosystèmes pourrait contribuer à augmenter les services de régulation biologique des ravageurs de culture. Il est établi que la biodiversité des milieux cultivés est modulée par des facteurs naturels et anthropiques agissant à différentes échelles spatiales, allant de la parcelle agricole au paysage, mais la compréhension des mécanismes écologiques qui produisent ces effets reste limitée. Pour produire des connaissances sur les déterminants des niveaux de régulations biologiques, il est nécessaire d’avoir recours à une approche à long terme qui mobilise à la fois une description des systèmes de cultures et une caractérisation écologique du contexte paysager. Pour répondre à cet enjeu a été constitué SEBIOPAG (http://sebiopag.inra.fr), un réseau pour l’étude des Services Ecosystémiques assurés par la BIOdiversité dans les Paysages Agricoles qui appartient au réseau national des observatoires de recherche sur la biodiversité (ECOSCOPE). Les objectifs sont de suivre sur le long terme, et dans des zones paysagères contrastées (i) les services écosystémiques rendus par la biodiversité, (ii) les facteurs qui les influencent (composition et structure du paysages, pratiques agricoles) et (iii) leur évolution dans le contexte des changements globaux (utilisation des terres, climatiques,…).Le réseau SEBIOPAG est constitué de cinq sites : Avignon, Dijon, Chizé, Rennes et Toulouse. En 2013, danschaque site, le paysage a été décrit et cartographié à l’aide de trois descripteurs : la proportion de cultures,l’hétérogénéité et la longueur des interfaces entre cultures et éléments semi-naturels. Puis, dans chaque site, 20 parcelles d’exploitants ont été choisies le long des trois gradients paysagers et d’un gradient d’intensité de pratiques. Les premières mesures (exposition de cartes de prédation) ont été effectuées en 2014 et portent sur une évaluation du potentiel de régulation biologique de trois espèces cibles : Acyrthosiphon pisum (pucerons), Ephestia kuehniella (lépidoptère) et Viola arvensis (adventice).

International audience; The objective of this article is to assess the relevance of a statistical method for hyperspectral image classification. We focus on the implementation of a functional method whose main objective is to consider each hyperspectrum as a continuous curve in order to predict its associated class. The implemented functional nonparametric discrimination method is a recently developed technique whose performance are greatly dependent on the choice of a "proximity measure". Behavior in practice of this method has been compared with three more standard others on two sets of hyperspectral data with supervised classification for 50 independent sets using a classification error rate criterion. Experimental results show that this method provides an interesting alternative to conventional methods.

Changes in forest cover in agricultural landscapes affect biodiversity. Its management needs some indications about scale to predict occurrence of populations and communities. In this study we considered a forest cover index to predict bird species and community patterns in agricultural landscapes in southwestern France. We used generalized linear models for that purpose with prediction driven by wooded areas? spatial distribution at nine different radii. Using 1064 point counts, we modelled the distribution of 10 bird species whose habitat preferences are spread along a landscape opening gradient. We also modelled the distribution of species richness for farmland species and for forest species. We used satellite images to construct a ?wood/non-wood? map and calculated a forest index, considering the surface area of wooded areas at nine radii from 110 m to 910 m. The models? predictive quality was determined by the AUC (for predicted presences) and r (for predicted species richness) criteria. We found that the forest cover was a good predictor of the distribution of seven bird species in agricultural landscapes (mean AUC for the seven species ¼ 0.74 for the radius 110 m). Species richness of farmland and forest birds was satisfactorily predicted by the models (r ¼ 0.55 and 0.49, respectively, for the radius 110 m). The presence of the studied species and species richness metrics were better predicted at smaller scales (i.e. radii between 110 m and 310 m) within the range tested. These results have implications for bird population management in agricultural landscapes since better pinpointing the scale to predict species distributions will enhance targeting efforts to be made in terms of landscape management. Fil: Pelosi, Céline. Institut National de la Recherche Agronomique; Francia Fil: Bonthoux, Sébastien. Institut National de la Recherche Agronomique; Francia. Unité Mixte de Recherche. Cités, Territoires, Environnement, Sociétés; Francia Fil: Castellarini, Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Institut National de la Recherche Agronomique; Francia Fil: Goulard, Michel. Institut National de la Recherche Agronomique; Francia Fil: Ladet, Sylvie Ladet. Institut National de la Recherche Agronomique; Francia Fil: Balent, Gérard. Institut National de la Recherche Agronomique; Francia

An estimation method for pairwise interaction potential of a stationary Gibbs point process is introduced by considering the case of observations located on a sphere. It is based both on Fourier decomposition of the potential and on minimum contrast estimation. It is defined when many independent realizations of the process are available. Consistency and asymptotic normality are proved for the resulting estimators. The method enables derivation of the choice of the potential function by embedded hypotheses testing. The method is applied to independent observations of root locations on internodes around stem of maize roots. The internodes are described as circles and we focus on the interaction function associated with the potential. Since a model with too many components seems to fail, we choose a sequential procedure based on embedded hypotheses testing to build a simpler model.

Matheron (1971) proposed an approximation of the extension variance in IR. We propose in this note an extension of this formula in IR2, based on a MacLaurin formula. Its application is shown in an example, the estimation of the maximum depressional storage of a soil surface.

International audience

The relationship between the locations of the clumps of sprouts, some morphological characteristics of the clumps and the local soil environment in an old sweet chestnut coppice are studied. The theory of marked point process, which has not yet been used extensively in forestry studies, is shown to be adequate for the analysis of this type of spatial data. The marks correspond to morphological characteristics of the clumps: “diameter”, “number of sprouts”, “height at one year”, and “height at three years”. Several covariance functions are described which give a method for exploring the spatial relationships within the stand. Some of these functions are introduced for the first time in an actual statistical analysis. By using these functions, it is shown that the clumps are regularly distributed. The variables “diameter” and “number of sprouts” are strongly spatially negatively correlated, whereas the heights are slightly or not correlated. By categorising the individuals according to the mark values, it is shown that the small clumps tended to be aggregated in the gaps between medium and large clumps. Values of heights in the ties of the distribution are related as well as their spatial correlation to the local soil environment.

International audience; Quantifying the impact of land-use changes on biodiversity is a major challenge in conservation ecology. Static spatial relationships between bird communities and agricultural landscapes have been extensively studied. Yet, their ability to mirror the effects of temporal land-use dynamics remains to be demonstrated. Here, we test whether such space-for-time substitution approaches are relevant for explaining temporal variations in farmland bird communities. We surveyed 256 bird communities in an agricultural landscape in southwest France at the same locations in 1982 and 2007, and quantified the same seven landscape descriptors for each period. We compared the effects of spatial and temporal landscape changes over this 25-year period on bird species distributions and three community-level metrics: species richness and two community indices reflecting birds' specialisation regarding local vegetation structure (local CSI) and landscape composition (landscape CSI). Landscape heterogeneity decreased between 1982 and 2007 and crop area increased sharply at the expense of grassland as a result of agricultural intensification. We found that the correlations between temporal changes in bird distributions or community metrics and landscape components were less consistent than their spatial relationships in each year. This result advocates caution when using a space-for-time substitution approach to assess the effects of landscape changes on biodiversity. Additionally, community metrics showed contrasted responses to landscape changes. Species richness and local CSI for each period were negatively related to the area of crops and positively related to landscape heterogeneity. Conversely, the landscape CSI was positively related to the area of crop and negatively to landscape heterogeneity. To understand the ecological processes linked to changes in farm landscapes, our study underlines the need to develop long-term studies with bird and habitat data collected during several periods, and particularly to consider multiple community indices in monitoring change.

International audience; Fire is acknowledged to be a factor for explaining the disturbance of vegetation dynamics interacting with other environmental factors. Depending on the fire regime, the amount of herbaceous biomass changes but depends on local conditions. Maintaining healthy vegetation and continuous vegetated cover on military training lands is important to provide for realistic soldier training experiences in a sustainable manner. The U.S. Army Integrated Training Area Management (ITAM) program is the organization responsible for ensuring training lands are available and accessible to meet Army operational needs now, and into the future, while attempting to minimize landscape degradation. At Fort Riley (Kansas), burning grassland is the main practice to prevent shrub encroachment and maintain accessible the training areas for the soldiers. One effort currently underway to assist the Fort Riley ITAM program is to clarify the importance and the role of fire on the dynamics of grassland vegetation in the training area. The image dataset is composed of one indicator related to vegetation activity changes and one indicator about fire regime that results from a combination of fire frequency and seasonality. All indicators were measured between 2000 and 2010 using remote sensing MODIS and Landsat time series. For the spatial statistic analysis, we implemented an approach in which a spatial GLM model is computed. Based on the spatial structure of the residuals, we built a stratification of the study area according to the spatial variations of the relationship established between vegetation activity changes and fire regime. The use of spatial statistical tools produces parsimonious models which we found to be consistent with expert knowledge.

Methods for interpolating soil moisture curves at unrecorded sites from measurements of soil water content at fixed pressure heads at sample points are investigated. A spatial prediction procedure was devised with two steps: interpolation of the retention data followed by fitting the Van Genuchten function to the interpolated values. For the interpolation, four different methods were considered. Two are based on a tessellation into areas of equal values, namely the nearest neighbour and the soil classification. The other two were autokriging and cokriging. The performance of these methods were compared in an area of 92 ha of alluvial soil where soil changes were gradual. Mean deviations and mean square deviations between predicted and observed retention data at validation sites were compared for two sampling densities. Kriging performed best in both cases. Cokriging was only slightly better than autokriging, and the latter is recommended for use. The performance of the nearest neighbour method diminished markedly with decreasing sampling density. Conversely, the performance of soil classification diminished only slightly, and this technique appeared as a reasonable alternative to kriging for sparse samples.

A non-parametric estimation method is proposed for the intensity of the Poisson process associated to a Boolean random function. The case studied is that of marks being half-spheres as primary functions, these half-spheres lying on a given horizontal plane. The proposed method is derived from the method presented in Gyorfi, Hardle, Sarda et Vieu [1989] for the case of time series. An application in soil science is presented.

The geostatistical analysis of multivariate data involves choosing and fitting theoretical models to the empirical matrix. This paper considers the specific case of the model of linear coregionalization, and describes an automated procedure for fitting models, that are adequate in the mathematical sense, using a least-squares like technique. It also describes how to decide whether the number of parameters of the cross-variogram matrix model should be reduced to improve stability of fit. The procedure is illustrated with an analysis of the spatial relations among the physical properties of an alluvial soil. The results show the main influence of the scale and the shape of the basic models on the goodness of fit. The choice of the number of basic models appears of secondary importance, though it greatly influences the resulting interpretation of the coregionalization analysis.

International audience

International audience; The relevance of vigilance activity to predator detection has been demonstrated in numerous studies. However, few studies have investigated the effect of one group member being vigilant on the probability of others being vigilant in group-forming prey species. Thus, we studied vigilance activity of eastern gray kangaroos Macropus giganteus that still experience occasional predation. We video recorded the behavior of all group members simultaneously and investigated the probability of a focal group member being vigilant (or nonvigilant) in relation to other individuals' vigilant and nonvigilant behaviors. Our results show that the decision of an individual to exhibit a vigilant posture depended on what it and other group members had been doing (scanning or foraging) at the preceding second and on group size. The probability of an individual being vigilant was positively affected by the proportion of companions that were vigilant at the previous second, confirming the existence in this species of a tendency for synchronization of individual vigilance. Group size affected individuals' vigilance in 3 ways. First, individuals were more likely to be vigilant if the proportion of their group mates that was vigilant was high, and this was strengthened with increasing group size. Second, the effect of the individual's own vigilance state (vigilant or not) at the previous second also increased with group size. Third, the probability of an individual being vigilant decreased with group size. These findings increase our understanding of the much-studied relationship between vigilance and group size. Key words: allelomimesis, group size, kangaroos, neighbor effect, probability of being vigilant, social facilitation, vigilance.

International audience; 1- Territoriality is commonly associated with resource defence polygyny, where males are expected to gain access to females by anticipating how resources will influence female distribution and competing for resource-rich sites to establish their zone of dominance. 2-We tested this hypothesis in European roe deer (Capreolus capreolus) by simultaneously assessing the influence of resources on female distribution and the influence of female distribution on male distribution and breeding success using paternity analyses. 3-Females did not fully distribute themselves among male territories in relation to resources. As a result, relative female abundance in a male's territory depended on territory size, but not on its habitat quality. In turn, relative female abundance in a male's territory determined, at least partially, his breeding success. 4-Interestingly, male territory size, and hence access to females, was partly determined by male body mass (all males) and by residual antler size (subadults only). The latter result suggests that large antlers may be important to young males for establishing their first territory, which is then usually retained for all subsequent reproductive seasons. 5-To conclude, although territoriality of male roe deer has certainly evolved as a tactic for ensuring access to mates, our results suggest that it does not really conform to a conventional resource defence polygyny strategy, as males seem to gain no obvious benefit from defending a territory in an area of high habitat quality in terms of enhanced access to mates. 6-This may explain the stability of male territories between years, suggesting that male territoriality conforms to an 'always stay' and 'low risk–low gain' mating strategy in roe deer.

International audience; Browsing by mammalian herbivores may help regulate the balance between woody and herbaceous vegetation where agricultural land has been abandoned. Until now, the potential of controlled grazing as a research tool has not yet been fully utilized. In this study, we used an enclosure-based experiment to assess the impact of browsing by red deer on the fate of seedlings on a woodland edge. Species, size, number of lateral shoots, and relative location of seedlings were recorded in 1 m2 plots (n = 57) distributed among four vegetation types. From autumn 2000 to winter 2002, after the stay of three tame hinds in the enclosure for 5-day periods in each season (a year-round deer density of 15 hinds/km2), we checked for loss or browsing damage of seedlings. From autumn 2000 to summer 2001, we additionally recorded the diurnal time spent feeding by the hinds during days 1, 3, and 5, and we simulated their food intake by hand during days 2 and 4. Mortality rates for willow Salix caprea and ash Fraxinus excelsior was higher than for silver fir Abies alba seedlings. Losses due to dehydration, which peaked under coniferous, were counterbalanced by growth of new seedlings. Loss due to browsing was uncommon. Deer impact on coniferous seedlings was insignificant all year long. More broad-leaved seedlings were browsed in spring and summer than in winter. Leader browsing increased with height, most of the taller seedlings occuring in herbaceous vegetation, especially wild cherry Prunus avium. Previously damaged seedlings suffered significantly higher leader browsing than previously undamaged ones. Behavioural observations showed that old pasture was selected by foraging deer all year-round. In autumn, spring and summer, due to quick depletion, the relative contribution of seedlings to the total food intake peaked during day 1, most (>75%) concerning wild cherry. Our results suggest that deer browsing on woody seedlings has more to do with species preference, height structure, growth, and seasonal phenology of seedlings than with induced mortality. Choice of previously damaged seedlings and non-random habitat use by deer can prove useful by minimizing natural regeneration of seedlings close to pastures. Further work is required on long term controlled browsing experiments to better understand natural regeneration of mixed woodland species.; L'abroutissement par les herbivores peut permettre le maintien de milieux ouverts après l'abandon de l'agriculture. Jusqu'à présent, cette possibilité d'utiliser un paturage contrôlé n'a pas été recherché complètement. Dans cette étude, nous avons réalisé une expérimentation dans un enclos pour mesurer l'impact de l'abroutissement du cerf sur une régénération forestière. La nature des essences, leur hauteur, le nombre de pousses et leur localisation ont été inventoriées sur des placettes d'1 m2 (n=57). Suite au passage de 4 biches imprégnées pendant 5 jours consécutifs à chaque saison (correspondant à une densité relative à l'année de 15 biches/km2)entre l'automne 2000 et l'hiver 2002, les inventaires ont permis de suivre la mortalité des semis et la pression d'abroutissement. Entre l'automne 2000 et l'été 2001, le temps passé à se nourrir dans la journée par les biches a été évalué (pour les jours 1,3 et 5) de même que la quantité ingérée a été estimée les jours 2 et 4. La mortalité des semis est plus importante pour le saule Salix caprea et le frêne Fraxinus excelsior que pour le sapin pectiné Abies alba. Les pertes dues à la sécheresse importante des semis sous les résineux étaient compensées par le développement de nouveaux semis. Les pertes dues à l'abroutissement sont négligeables. L'impact du cerf sur la régénération des résineux est négligeable tout au long de l'année. Les semis d'essences feuillues sont consommées essentiellement au printemps et en été. L'abroutissement de la pousse terminale des feuillus est corrélée à leur hauteur notamment pour les semis de merisier. les semis auparavant consommés sont plus sujets à être abroutis que ceux qui ne l'ont jamais été. Les observations directes ont montré que la partie de l'enclos correspondant à une ancienne pâture était plus utilisée par les biches tout au long de l'année. A l'automne, au printemps et en été la contribution relative des semis d'essences forestières à la quantité de nourriture ingérée passait par un pic (>75%)puis diminuait fortement après la première journée passée dans l'enclos en raison d'une forte diminution du stock disponible notamment de semis de merisiers. Nos résultats suggèrent que les effets de l'abroutissement du cerf sur l'acquisition de la régénération sont peu importants et que le problème principal est lié à la nature des essences et à leur relative attractivité, leur hauteur, la saison. Pour limiter l'impact du cerf en raison de l'utilisation de son habitat, il peut s'avérer utile de ne pas mettre en régénération des zones limitrophes de patures. Des travaux complémentaires au travers d'expérimentations de ce type sur le long terme pourront permettre de mieux comprendre les interactions entre le cerf et l'acquisition des régénérations forestières.