Spatiotemporal variation in animal space use is critical for understanding how individual animals respond to changes in resource availability across space and time. My study was aimed to: 1) determine functional responses of habitat selection by eastern wild turkeys (Meleagris gallopavo silvestris) across 7 study sites in Mississippi; and 2) determine the effect of temporal vegetation variation on order-II habitat selection by wild turkeys over 12 years. I developed resource selection functions using radio telemetry location data. Individual-specific coefficients of order-III habitat selection for forest were related inversely to forest availability in meta-regressions. Yearly coefficients of order-II habitat selection for forest were related inversely to the mean normalized difference vegetation index (NDVI) in April, but the coefficients for open fields were related positively to coefficient of variation in the NDVI from March to May. Wild turkeys exhibited functional responses of habitat selection to spatiotemporal forest availability across Mississippi.

<p>Cilj ovog istraživanja je bio da se utvrde efekti različitih disciplina u karateu (sportske borbe - kumite i forme - kata) na morfo-funkcionalne karakteristike karatista seniora. Pored ovoga su utvrĎivane i razlike u odnosu na dužinu trenažnog staža, kao i akutni fiziolo&scaron;ki odgovor na specifično fizičko opterećenje tokom simulacije takmičenja. Uzorak je obuhvatio 72 ispitanika koji su prvenstveno bili podeljeni na kata (n = 33) i kumite (n = 39) grupu, a potom i u odnosu na trenažni staž u tri grupe (starija n = 23, srednja n = 24 i mlaĎa n = 25). Svi ispitanici su testirani kroz bateriju od 36 testova za procenu morfo-funkcionalnog statusa. Rezultati su pokazali razlike u pojedinim morfo - funkcionalnim karakteristikama ispitanika u odnosu na takmičarsku disciplinu. Kumite borci su imali izraženiju longitudinalnost (p &lt; 0,01), dok su kata takmičari imali izraženije potkožno masno tkivo praćeno većom ko&scaron;tanom masom (p &lt; 0,05). TakoĎe su ispitanici kata grupe pokazali superiorniju fleksibilnost donjih ekstremiteta (p &lt; 0,05), dok su kumite ispitanici bili bolji u pokazateljima apsolutne snage skokova kao i aerobnih sposobnosti (p &lt; 0,01). U odnosu na trenažni staž javile su se razlike u svim varijablama za procenu vertikalne skočnosti (visini skoka i maksimalnoj snazi), funkcionalnim pokazateljima kao i varijablama za procenu mi&scaron;ićne snage u korist najstarije grupe (p &lt; 0,05). Razlike<br />dobijene u fiziolo&scaron;kim odgovorima na akutno opterećenje kroz specifičnu takmičarsku disciplinu, kao i razlike u praćenoj temperaturi jezgra tela nisu bile značajne. Rezultati ovog istraživanja ukazuju da treniranjem različitih karate disciplina dolazi do odreĎenih specifičnih morfo-funkcionalnih promena u organizmu. Na ove promene bitno utiče i trenažni staž, odnosno vreme provedeno u specifičnom treningu.</p> / <p>The aim of this study was to determine the effects of different competitive disciplines in karate (sports fight - kumite and forms - kata) on morpho-functional characteristics in senior karate athletes. In addition, differences in relation to training experience, as well as the acute physiological response to a specific physical exertion during the simulated competition were determined. The sample included 72 athletes primarily divided into kata (n = 33) and kumite (n = 39) group, and to training experience into three groups (oldest: n = 23, medium: n = 24, and youngest: n = 25). All subjects were evaluated through a battery of 36 morpho-functional tests. Differences were found between two competitive disciplines. Kumite athletes had significantly longer dimensions (p &lt; 0.01), whereas kata competitors had more pronounced subcutaneous adipose tissue accompanied by higher bone mass and superior flexibility (p &lt; 0.05). Furthermore, kumite athletes had better indicators of absolute power in jumping performance and aerobic capacity (p &lt; 0.01). Differences also occurred in all variables of vertical jumping assessment (jump height and maximum power), functional indicators (p &lt; 0.05) and muscle strength evaluation (p &lt; 0.01) in relation to training experience. All differences found were in favor of the oldest group. No differences were found in physiological responses to acute load of the specific competitive discipline, or in body core temperature measured. The results of this<br />research indicate that training for different karate disciplines had led to certain specific morpho-functional changes in the body. These changes were partially affected by specific training regimes and training experience.</p>

The diet of an animal plays a fundamental role in its ecology, and the consequence of a specific diet may be more pronounced in mammals with a specialised diet that are more reliant on a specific food type. This can have a dramatic effect on its activity patterns, home range size and the interaction with heterospecifics. Investigating the diet of specialist mammals and the subsequent effects it will have on their ecology is thus vital to the management and subsequent conservation of the species, and crucial to our understanding of how the animal can survive and reproduce. In this thesis I investigate the effect that the diet of the aardwolf, a highly specialised myrmecophage, has on its ecology. Aardwolves feed predominantly on one genus of termite, Trinervoides spp., and are thus extremely dependent on the abundance and distribution of this arthropod. I firstly investigated the effect of temperature and rainfall on arthropod abundance and diversity, and further investigated the variation of arthropod abundance and diversity across the four habitat types at study site. This is one of a few studies that have been conducted on arthropod abundance and diversity in an arid environment and the findings show that in an arid environment arthropods are mainly influenced by temperature rather than rainfall. This is in contrast to studies in temperate and forest habitats where rainfall is the most important abiotic factor determining the abundance and diversity of arthropod assemblages. Habitat type still plays a major role in the abundance and diversity of arthropods, and habitat types that are more complex and diverse have both a higher diversity, and abundance of arthropods than other habitats. Due to the absence of prey items during the colder months of the year I investigated the diet of aardwolves to see if they display a switch in diet. This included an investigation into the seasonal variation of diet from a detailed scat analysis, using a newly developed method to assess scat content. The analysis of scats revealed that, contrary to previous studies, aardwolves showed no switch in diet and continued to feed on Trinervitermes. Using the data from the scat analyses and the information from the abundance and diversity of arthropods at the study site I expanded the study to investigate the functional responses of the aardwolf to change in prey abundance at the locality. Aardwolves demonstrate a Type I functional response to changes in prey abundance, a response that is normally found in plankton feeders. The expected functional response for specialist animals would be Type II response, and I propose that the Type I response seen in aardwolves is probably as a result of a limited handling time which reduces time spent foraging. The abundance of termites thus had a clear effect on the diet of aardwolves, showing that they feed on fewer when they are unavailable, and as such I investigated the effect of termite densities on home range sizes. The number of termite mounds in a home range influenced the size of the home range, and aardwolves with larger home ranges had a lower density of termite mounds. In contrast to previous studies, large overlaps between neighbouring individuals were recorded and indeed three male aardwolves shared a common den. I propose that the reason behind the overlap of home ranges is that a higher prey abundance during my study period occurred and as a consequence aardwolves did not need to defend an area to protect this resource. T. trinervoides has thus played a keystone role in driving the biology of the aardwolf and shaping many aspects of its ecology. / Thesis (PhD)--University of Pretoria, 2021. / South African Research Chair Initiative chair of Mammal Behavioural Ecology and Physiology / Zoology and Entomology / PhD / Unrestricted

Au sein de son aire de répartition, le chevreuil (Capreolus capreolus) rencontre des conditions environnementales variables et contrastées qui engendrent une grande variété de patrons d'utilisation de l'espace. Jusqu'à présent, aucune étude n'a clairement établi un lien entre les différents patrons d'utilisation de l'espace et les conditions environnementales dans lesquelles le chevreuil évolue, ce qui limite notre compréhension des mécanismes impliqués dans le processus de sélection d'habitat. Grâce aux suivis télémétriques de nombreux chevreuils dans 4 sites avec des conditions environnementales fortement variables et contrastées nous avons cherché à établir un lien entre les variations des conditions environnementales et les variations des patrons d'utilisation de l'espace. Ainsi, nous avons démontré qu'en milieu alpin, les chevreuils adaptent l'amplitude de leurs déplacements en fonction des variations spatiales et temporelles de la disponibilité des ressources ainsi qu'en fonction des conditions d'enneigement. Contrairement aux précédentes études sur l'utilisation de l'espace par le chevreuil en milieu de montagne, nous avons montré que les mouvements des chevreuils au sein de notre aire d'étude correspondaient à un processus de sélection d'habitat de troisième ordre (48 cas; 89%) plutôt qu'à de la migration partielle, puisque très peu d'individus (6 cas; 11%) avaient stabilisé leurs déplacements au sein de domaines vitaux distincts au cours des saisons. Par ailleurs, nous avons démontré que le comportement de sélection d'habitat des chevreuils à l'échelle du domaine vital était très variable entre les populations mais également au sein de chaque population. Ainsi dans les forêts les plus pauvres où les ressources sont spatialement séparées au sein de différents habitats, nous avons démontré que les chevreuils étaient contraints de réaliser des compromis, générant des réponses fonctionnelles en sélection d'habitat. Au contraire, dans les habitats les plus riches où les ressources sont disponibles dans toutes les catégories d'habitat, nous n'avons pas observé de réponse fonctionnelle puisque les chevreuils n'étaient pas contraints et donc ne réalisaient pas de compromis. De plus, nous avons démontré que les chevreuils avec une même composition de domaine vital dans différents sites, utilisaient les ressources différemment. Ces résultats démontrent que la façon dont une ressource est utilisée ne dépend pas seulement de son niveau de disponibilité au sein du domaine vital mais varie également en fonction des conditions environnementales. De ce fait, il est impératif de tenir compte des conditions environnementales au sein d'un site pour mieux comprendre les mécanismes impliqués dans l'émergence des différents patrons d'utilisation de l'espace observés chez les ongulés. Enfin, nous avons tenté d'établir un lien entre les variations observées dans les patrons de sélection d'habitat à différentes échelles et la valeur sélective des chevreuils dans les populations de Chizé et de Trois-Fontaines pour lesquelles les données requises étaient disponibles, mais nous n'avons pu mettre en évidence aucun effet du comportement de sélection d'habitat sur la valeur sélective individuelle des femelles / Across its distributional range, the European roe deer (Capreolus capreolus) encounters a wide range of environmental conditions that generate marked differences of space use patterns. However, linking variation in space use by animals in different populations facing contrasted environmental conditions to site-specific conditions has not yet been investigated, which currently limits our understanding of the mechanisms involved in habitat selection. Using data collected on roe deer equiped with VHF and GPS collars in four different sites with contrasted environmental conditions, we aimed to fill this knowledge gap by relating variations in space use by animals in variable environmental conditions. We found that roe deer in Alpine environment adapt the magnitude of their movements to the spatial and temporal variation in resource availability, but also to the amount of snow cover. Contrary to previous studies on roe deer performed in mountain ranges, we showed that roe deer movements in the northern French Alps corresponds to the usage of various habitat components within the home range (third order habitat selection process; 48 cases; 89%) rather than as partial migration because very few (6 cases; 11%) roe deer stabilized their activity in distinct home ranges across seasons. Moreover, we found that roe deer markedly differed in habitat selection within their home range, both within and among populations. Roe deer facing poor environmental conditions with spatially segregated resources should trade one resource for another one, which generates a functional response in habitat selection. At the opposite, roe deer benefiting from rich environmental conditions in their home range do not have to trade one resource for another one and therefore did not display any functional response. In addition, our results suggest that a same habitat composition can lead to widely different space use patterns. These findings demonstrate that the way a given habitat type is used in relation to its availability strongly varies in response to environmental conditions, so that accounting for variation in environmental conditions is required to provide a reliable assessment of the mechanisms involved to shape the diversity of space use patterns we currently observed in ungulates. Finally, we looked for linking observed variation in space use patterns to indivudual fitness of female roe deer in the populations of Chizé and Trois-Fontaines for which the required data were available. However, we did not find any evidence of a positive effect of the intensity of habitat selection on individual female fitness

La structure et l’intensité des interactions ressources-consommateurs qui forment les réseaux trophiques régulent une très grande partie des transferts de biomasse mais aussi de contaminants biologiques et chimiques dans les écosystèmes. L’objectif de la thèse est de développer des modèles permettant d’étudier les mécanismes de transport des contaminants et d’évaluer ainsi d’une part la dynamique des maladies infectieuses et des pollutions chimiques, et d’autre part les réponses des réseaux trophiques soumis à ces contaminations.[...] À l’issue de ces travaux, une quatrième étape de la thèse a été d’intégrer les interactions trophiques, les dynamiques des parasites et les impacts des pollutions dans des méta-écosystèmes (i.e. avec dispersions d’individus entre écosystèmes). En utilisant la théorie des matrices aléatoires nous avons établi des mesures des risques d’émergence de parasites que nous avons évalués en fonction des perturbations extérieures.L’étude a ainsi montré que ces perturbations augmentent les risques épidémiques, mais que ces risques pouvaient être réduits par la dispersion des individus (sains et infectés) sous certaines conditions qui sont,par exemple pour les TTP, un nombre d’espèces plus grand que le nombre d’écosystèmes connectés, et un taux de virulence plus faible que le taux de contagion.Ainsi, dans un contexte planétaire d’augmentation des pressions anthropiques sur les écosystèmes,cette thèse de modélisation apporte un ensemble d’outils et de développements conceptuels permettant d’analyser quantitativement et qualitativement les transferts et les impacts des contaminants sur les écosystèmes. / Structure and strength of trophic interactions shaping food webs regulate a large part of biomass andenergy transfer in ecosystems, but also the transfer of biological and chemical contaminants. The aim ofthe PhD thesis is to develop models describing the mechanisms of contaminant transmission and using them to study the dynamics of infectious diseases and chemical pollutions, and also the response of trophic networks subject to those contaminations.[...] Following those works, a fourth step of the thesis has been to integrate trophic interactions, parasite dynamics and pollutions effects in order to study the stability of meta community (i.e. spatially connectedcommunities) and the risk of disease outbreaks. To do so, we use the theory of random matrices andwe introduced new criteria of metacommunity stability and of disease outbreak in metacommunity, both under external pressures. The study showed that external perturbations increase the risk of epidemics,but that those risks could be reduced with the dispersal of individuals (susceptible and infectious) underspecific conditions such as, for TTP, a greater number of species than that of connected ecosystems, and a smaller virulence than the contagion rate.In this way, in a context of planetary increase of anthropogenic pressures on ecosystems, this PhD thesis in modeling provides a set of tools and conceptual developments suitable to analyze quantitatively and qualitatively the transfers and impacts of contaminants in ecosystems.