La dispersion chez le chevreuil européen, Capreolus capreolus, dans un paysage hétérogène

La dispersion, définie comme l'ensemble des mouvements qui éloigne les organismes de leur lieu de naissance de façon permanente, est un processus biologique fondamental de par son rôle déterminant dans la dynamique des populations. Dans la plupart des populations, tous les individus ne dispersent pas, et les individus qui dispersent ne sont pas un échantillon aléatoire de la population. Le but de cette thèse est d'appréhender les facteurs qui peuvent être une source de variabilité entre les individus dans leur comportement de dispersion au cours des différentes phases de la dispersion natale chez une espèce de grand herbivore, le Chevreuil. Dans une population de chevreuils évoluant dans un milieu hétérogène, plus de 100 individus juvéniles ont été capturés et équipés de collier GPS entre 2003 et 2012, permettant un suivi régulier de leurs déplacements pendant plus d'une dizaine de mois. Il a ainsi été mis en évidence l'importance de facteurs internes (tels que la masse corporelle des individus, leurs traits de comportement avant dispersion ou leur sexe) et externes aux individus (tel que le degré d'ouverture du paysage) au cours des différentes phases de la dispersion (émigration, trajet, immigration). Une variabilité inter-individuelle du comportement de dispersion s'observe tout au long du processus de dispersion, de la phase préparatoire à l'installation dans un domaine post-dispersion. De plus, plusieurs particularités du comportement de dispersion semblent participer à la réduction des coûts directs et indirects qui lui sont associés. Cette variabilité pouvant avoir des répercutions importantes sur le fonctionnement de la population, révèle ainsi l'importance de sa prise en compte dans les études sur la dispersion.Dispersal, defined as the movements that take individuals away from their birth site permanently, is a fundamental biological process that impact population dynamic and genetic. In most populations, not all individual disperse, and dispersers are not a random subset of the source population. The general aim of this thesis is to better understand the factors generating inter-individual variability across the three phases of the dispersal behaviour in a large herbivore specie, the European roe deer. In a heterogeneous landscape, more than 100 juveniles from a natural population were captured and equipped with a GPS collar between 2003 and 2012 and then intensively monitored during approximately ten month. This study highlights the role of internal factors (such as individual body mass, behavioural traits before dispersal or sex) and external factors (such as degree of landscape openness) across the different phases of the dispersal process (emigration, transience, immigration). A high inter-individual variability of the dispersal behaviour was observed across the whole process, from the preliminary phase to the settlement in the post-dispersal home range. Moreover, some behavioural characteristics of dispersal should reduce the direct and indirect costs associated with dispersal. Due to the important consequences on population fonctionning this inter-individual variability on dispersal behaviour may have, it seems essential to take into account this factor when studying dispersal

Implications of the forage maturation hypothesis for activity of partially migratory male and female deer

Partial migration is common in a large variety of taxa in seasonally variable environments. Understanding the mechanisms underlying migration is important, as migration affects individual fi tness. Migratory herbivores bene fi t from delayed forage maturation and hence higher food quality during migra- tion and at their summer range, termed the forage maturation hypothesis (FMH). The link between diet quality and rumination time allows migrants eating a higher quality diet to spend less time on rumination, and they can thus allocate more time to additional feeding. However, such an argument implicitly assumes that deer are energy maximizers, while studies have reported also time minimization strategies under risk of predation. Male and female distributions are limited by different factors linked to both body size differ- ences and reproductive strategies, but there is no study investigating differences in activity pattern accord- ing to the individual migratory patterns for male and female deer. We here unify the FMH with the hypotheses predicting sex-speci fi c time allocation strategies. To test predictions of sex-speci fi c activity of resident and migratory red deer ( Cervus elaphus ), we analyzed activity data of 286 individuals that were fi tted with GPS collars from a population in western Norway. While migrants were more active during the migration itself, we found no differences in activity pattern between migrant and resident deer during the main growth season, neither in terms of proportion of daily time active nor in terms of daily mean movement speed, thus rejecting that deer were energy maximizers. Overall, we found that females were more active during the main growth season even after controlling for body size differences. These patterns are consistent with patterns predicted from sexual segregation theory linked to the reproductive strategy hypothesis. Our study highlights how the understanding of migration can be advanced by considering it in the context of different reproductive strategies of males and females.publishedVersio

Wherever I may roam-Human activity alters movements of red deer (Cervus elaphus) and elk (Cervus canadensis) across two continents

Human activity and associated landscape modifications alter the movements of animals with consequences for populations and ecosystems worldwide. Species performing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement expression, using the standardized metric Intensity of Use, reflecting both the directionality and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topography, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strongest driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric-based movement expression across widely distributed populations of a deer genus, contributing to the understanding and prediction of animals' responses to human activit

Wherever I may roam—Human activity alters movements of red deer (Cervus elaphus) and elk (Cervus canadensis) across two continents

Human activity and associated landscape modifications alter the movements of ani-mals with consequences for populations and ecosystems worldwide. Species perform-ing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement ex-pression, using the standardized metric Intensity of Use, reflecting both the directional-ity and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topogra-phy, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strong-est driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric- based movement expression across widely distributed populations of a deer genus, contribut-ing to the understanding and prediction of animals' responses to human activity.publishedVersio

Roe deer Capreolus capreolus dispersal in a heterogeneous landscape

Dispersal, defined as the movements that take individuals away from their birth sitepermanently, is a fundamental biological process that impact population dynamic and genetic.In most populations, not all individual disperse, and dispersers are not a random subset of thesource population. The general aim of this thesis is to better understand the factors generatinginter-individual variability across the three phases of the dispersal behaviour in a largeherbivore specie, the European roe deer. In a heterogeneous landscape, more than 100juveniles from a natural population were captured and equipped with a GPS collar between2003 and 2012 and then intensively monitored during approximately ten month. This studyhighlights the role of internal factors (such as individual body mass, behavioural traits beforedispersal or sex) and external factors (such as degree of landscape openness) across thedifferent phases of the dispersal process (emigration, transience, immigration). A high interindividual variability of the dispersal behaviour was observed across the whole process, fromthe preliminary phase to the settlement in the post-dispersal home range. Moreover, somebehavioural characteristics of dispersal should reduce the direct and indirect costs associatedwith dispersal. Due to the important consequences on population fonctionning this interindividual variability on dispersal behaviour may have, it seems essential to take into accountthis factor when studying dispersal.La dispersion, définie comme l'ensemble des mouvements qui éloigne les organismes de leur lieu de naissance de façon permanente, est un processus biologique fondamental de par son rôle déterminant dans la dynamique des populations. Dans la plupart des populations, tous les individus ne dispersent pas, et les individus qui dispersent ne sont pas un échantillon aléatoire de la population. Le but de cette thèse est d'appréhender les facteurs qui peuvent être une source de variabilité entre les individus dans leur comportement de dispersion au cours des différentes phases de la dispersion natale chez une espèce de grand herbivore, le Chevreuil. Dans une population de chevreuils évoluant dans un milieu hétérogène, plus de 100 individus juvéniles ont été capturés et équipés de collier GPS entre 2003 et 2012, permettant un suivi régulier de leurs déplacements pendant plus d'une dizaine de mois. Il a ainsi été mis en évidence l'importance de facteurs internes (tels que la masse corporelle des individus, leurs traits de comportement avant dispersion ou leur sexe) et externes aux individus (tel que le degré d'ouverture du paysage) au cours des différentes phases de la dispersion (émigration, trajet, immigration). Une variabilité inter-individuelle du comportement de dispersion s'observe tout au long du processus de dispersion, de la phase préparatoire à l'installation dans un domaine post-dispersion. De plus, plusieurs particularités du comportement de dispersion semblent participer à la réduction des coûts directs et indirects qui lui sont associés. Cette variabilité pouvant avoir des répercutions importantes sur le fonctionnement de la population, révèle ainsi l'importance de sa prise en compte dans les études sur la dispersion

La dispersion chez le chevreuil européen, Capreolus capreolus, dans un paysage hétérogène

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Ontogeny of personality in roe deer (Capreolus capreolus)

International audiencePersonality is often described as individual differences that are consistent across time and context. Numerous traits are often used to characterize personality, such as sociability, aggressiveness, exploration, boldness and neophobia. The existence of personality in the animal kingdom is not yet admitted by the entire research community, and relatively few studies have investigated the ontogeny of personality. This longitudinal study explored if roe deer (Capreolus capreolus) exhibited consistent individual differences (personality) in a neophobic situation, and if said personality evolved throughout the years (fawn to adulthood). 1/ We first hypothesized that roe deer would indeed exhibit consistent individual differences and confirm the existence of personality in this species. 2/ Secondly, we hypothesized that personality would stay consistent across time (both fawns and adults would show unique personality profiles). The findings of our longitudinal study of the existence and ontogeny of personality in roe deer exposed to a novel object context show a time consistency of distinct behavioral profiles. This experiment is part of a larger ongoing project as multiple cohorts are being tested at 1 and 3 years old both in novel object and isolation context at the CEFS. Roe deer behavior is thus being studied in different contexts and at different life stages which could bring us an answer on the existence and ontogeny of personality in this species

Data from: Individual quality and age but not environmental or social conditions modulate costs of reproduction in a capital breeder

Costs associated with reproduction are widely known to play a role in the evolution of reproductive tactics with consequences to population and eco-evolutionary dynamics. Evaluating these costs as they pertain to species in the wild remains an important goal of evolutionary ecology. Individual heterogeneity, including differences in individual quality (i.e., among-individual differences in traits associated with survival and reproduction) or state, and variation in environmental and social conditions can modulate the costs of reproduction; however, few studies have considered effects of these factors simultaneously. Taking advantage of a detailed, long-term dataset for a population of feral horses (Sable Island, Nova-Scotia, Canada), we address the question of how intrinsic (quality, age), environmental (winter severity, location), and social conditions (group size, composition, sex ratio, density) influence the costs of reproduction on subsequent reproduction. Individual quality was measured using a multivariate analysis on a combination of four static and dynamic traits expected to depict heterogeneity in individual performance. Female quality and age interacted with reproductive status of the previous year to determine current reproductive effort, while no effect of social or environmental covariates was found. High quality females showed higher probabilities of giving birth and weaning their foal regardless of their reproductive status the previous year, while those of lower quality showed lower probabilities of producing foals in successive years. Middle-aged (prime) females had the highest probability of giving birth when they had not reproduced the year before but no such relationship with age was found among females that had reproduced the previous year, indicating that prime-aged females bear higher costs of reproduction. We show that individual quality and age were key factors modulating the costs of reproduction in a capital breeder but that environmental or social conditions were not, highlighting the importance of considering multiple factors when studying costs of reproduction

data_MS_ECE-2016-11-01203

Full data used for the analyse