The objectives of my research were twofold: 1) to evaluate new technologies (camera traps and a new type of GPS collar) for studying large mammals in tropical forests, and 2) to study the ecology of the lowland tapir (Tapirus terrestris) in the Peruvian Amazon. Camera traps proved to be an efficient tool for mammal inventories in tropical forests. They recorded 24 out of 28 terrestrial medium and large sized mammal species with a survey effort of 2340 camera days. Camera traps were also able to reveal important information on habitat use, activity patterns and the use of mineral licks for five Amazonian ungulate species. There was a high spatial overlap between all the species with the grey brocket deer being the only species that was restricted to terra firme forest. White-lipped peccaries, tapirs and red brocket deer frequently used mineral licks, whereas collared peccaries and grey brocket deer were hardly ever observed at licks. A new type of GPS collar (TrackTag) tested in this study performed well under the dense canopy of a tropical forest. Position success rates of 87% for stationary collars and 48% for collars placed on tapirs were comparable to data obtained with GPS collars in temperate forests. The mean location error for stationary collars inside the forest was 28.9 m and the 95% error was 76.8 m. GPS collars placed on six tapirs for seven to 182 days showed home range sizes of 102 to 386 hectares. Tapirs were mainly nocturnal and areas used for foraging during the night differed from resting sites used during the day. Tapirs could walk up to 10 km to visit a mineral lick. Visits were irregular at intervals of a few days up to 36 days. The analysis of 135 tapir dung samples showed that tapirs ingest seeds of over 120 plant species. Seeds were found throughout the year but monthly species diversity was related to fruit availability. The size distribution of ingested seeds was related to availability. Most seeds were less then 10 mm wide, but seeds up to 25 mm were found. Both camera traps and TrackTag GPS collars greatly increased the possibilities for studying large rainforest mammals. The two technologies collect complementary information and each one is suited for a different set of questions.

The objective of this thesis was to examine whether forest structure and ground vegetation could explain the habitat choices of the reindeer within similar forest stands. The field work was carried out on 60 sites scattered across a part of the winter grounds for Vilhelmina Norra reindeer herding district. All sites were situated within so-called core and key areas, i.e. areas which the herding district sees as necessary for the reindeer husbandry in the area. Information from GPS-collared reindeer were used to create RIVO (by the Reindeer Identified [as] Important Areas) maps, where areas the reindeer preferred were shown. The results showed that the core and key areas were not significantly different from each other regarding the forest structure, nor the vegetation, but there were some differences in terms of the habitat choice of the reindeer and when the core and key areas were combined with RIVO. The differences concern mainly the coverage of ground lichens, epiphytic lichens and moose presence. Results from other studies suggest that the reindeer habitat selection is dependent on the weather and snow conditions, and looks very different from year to year. The snow conditions are in turn affected by the forest structure, so it is important that the grazing grounds have a heterogeneous forest landscape, including areas which under normal circumstances would not be seen as important for the reindeer husbandry.

Knowledge of scale-dependent factors that affect the distribution of ungulate herds, such as cattle, is essential for the development of more accurate predictive models of animal movement and the management of sustainable agriculture. Our objectives were to evaluate the seasonal and diurnal patterns of herd spread, explore grouping dynamics, and the influence of dominance ranks, seasonal changes in forage biomass, use of shade, water and supplemental feed areas on cattle distribution. Positional and activity information of eleven free-ranging Bonsmara, Bos taurus, cows were obtained at five minute intervals using Global Positioning System collars. We conducted a total of 12 trials each of three weeks from August 2007 to August 2009 in a 457ha shrub-dominated savanna in South Texas. Spread was obtained by calculating the average Euclidean distance of individuals to the center of the herd. The association software package, ASSOC1, was used to analyze spatio-temporal interactions. Normalized Difference Vegetation Index, an indicator of available forage biomass, was calculated using satellite imagery. Number of GPS fixes was used as an indicator of animal use of shade patches and water and supplemental feeding areas. In this semi-arid environment, herd spread was greatest and subgroup division occurred during summer when forage biomass was high. Herd spread was the least and shade patches were used more during winter when forage biomass was low. Throughout the year spread was smallest and use of shade patches highest during the midday period compared to other periods of the day. Location of individuals in the center of the herd was not associated with their dominance ranking. There was no significant overall pattern of seasonal changes in cattle use of water and supplemental feeding areas. Seasonal forage availability and shade patches seem to have a greater influence on herd dispersion patterns and grouping dynamics than any effect of social dominance. Herd distribution is likely related to changes in forage biomass and temperature fluctuations which drive compensatory night-time feeding and thermoregulatory actions. Accurate ethological studies of herds depend on our ability to understand herd dynamics at multiple scales that affect and are relevant to animal's response to the landscape.

African elephants are ‘keystone’ species with respect to biodiversity conservation in Africa since they maintain habitats that support several animal communities by changing vegetation structure through foraging and by dispersing seeds between landscapes. Elephants are also ‘flagship’ species because, given their impressive size, they can make people sympathetic and stimulate local and international concerns for their protection. Economically, elephants contribute to national revenues as tourists are willing to pay to watch them. Despite all these factors, little is known however about elephant movement and how they utilize resources, especially in miombo-wetland ecosystems. This thesis investigates how elephants utilize resources in a miombo-wetland ecosystem in the Ugalla landscape of Western Tanzania over different protected areas containing different resource users. Using Global Positioning System (GPS) collars fitted to six elephants, it was observed that some elephant families are not confined in one protected area in the Ugalla landscape. Rather, they moved readily between different protected areas. Elephant movements were restricted to areas near the rivers, especially the Ugalla River, during the dry season and were dispersed widely during the wet season. As they move, elephants in the miombo woodlands of Ugalla selected the most abundant woody plants for browsing. Common to many woody plants, the browsed plants were short of mineral nutrients (e.g., sodium, calcium). Elephants obtained additional minerals by eating soils from certain termite mounds. Soils from termite mounds are richer in mineral elements (e.g., sodium, calcium, iron) compared to soils from the surrounding flood plain or compared to the browsed plants. However, the recorded termite mounds from which elephants eat soils were not evenly distributed in the landscape but confined mainly to the flood plains in the Ugalla Game Reserve. The Ugalla River, which is the main source of water for the elephants and other animals and also supports fishing activities by the local people in Ugalla during the dry seasons, is infested by the water hyacinth (Eichhornia crassipes). Such infestation potentially limits access to these precious surface water supplies. In addition at the regional level, the Ugalla River is among the major rivers that flow into the Lake Tanganyika which is shared by the countries of Tanzania, Burundi, Democratic Republic of Congo and Zambia. Thus, the spread of water hyacinth if left unchecked threatens to impact Lake Tanganyika, affecting many countries and ecosystem services. This thesis highlights that sustainable conservation of biodiversity in different protected areas in the Ugalla landscape requires an integrated management approach that will embrace conservation of different interrelated landscape resources required by both wildlife and the rural poor populations for their livelihoods. Regular coordinated wildlife anti-poaching patrols should be initiated across the entire Ugalla landscape because the elephants, among other wildlife, utilize different protected areas in Ugalla. Local communities should also be engaged in conservation initiatives (e.g., controlling the spread of the water hyacinth) as these directly impact local livelihoods. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.</p> / INTEGRATED NATURAL RESOURCES MANAGEMENT

Les modifications du paysage engendrées par les activités humaines sont une des causes majeures du déclin de la biodiversité. En générant une perte de la connectivité fonctionnelle du paysage, elles limitent les déplacements des individus et entraînent la rupture des flux de gènes, processus clés dans le maintien et la persistance des populations. Cependant, le lien entre ces processus et la structure du paysage est encore mal compris. Dans ce contexte, nous avons conduit une étude sur la Martre des pins, une espèce a priori forestière, bien que capable de s’installer durablement dans des paysages fragmentés. A partir de l’analyse de la variabilité génétique de groupes échantillonnées sur 13 sites forestiers à l’échelle de la région Champagne-Ardenne, et du suivi des déplacements d’individus à fine échelle, en milieu continu et fragmenté, nous avons estimé la résistance du paysage aux différents déplacements, c’est-à-dire dans quelle mesure ceux-ci sont freinés ou facilités par les éléments du paysage. Nous avons mis en évidence que les déplacements sont freinés, d’une part par la présence d’une large plaine agricole, et d’autre part, par certaines infrastructures de transport. Nous avons également mis en évidence que les déplacements des martres entre les taches d’habitats sont facilités par la présence de haies et que la hauteur du couvert végétal des habitats non boisés pourrait jouer un rôle dans ces déplacements. Cette étude apporte d’importantes connaissances sur l’écologie des déplacements de la Martre des pins et souligne la nécessité de la prise en compte de la réponse des organismes dans l’établissement des futurs réseaux écologiques. / Landscape changes, generated by anthropogenic activities, are widely recognised as one of the main causes of global biodiversity decline. Leading to a loss of functional landscape connectivity, they disrupt movements and gene flow which play a primordial role for the persistence of populations. However, the relationship between these processes and landscape structure remains unclear. In this context, we studied landscape connectivity in European pine marten, a forest species present in fragmented landscapes. We evaluated landscape resistance, i.e. how landscape features impede or facilitate movements and gene flow, analysing genetic variability of groups sampled in 13 forest sites of the Champagne-Ardenne regional area, and studying individual fine-scale movements in both continuous and fragmented areas. We showed that intensive agricultural plain and certain linear infrastructures could impede movements. In addition, we showed that hedgerows facilitate movements between forest patches and we suggested that vegetation height of open habitats could play a role for these movements. This study provides important insights on movement ecology of the European pine marten and underlines the need to take into account responses of organisms in the establishment of ecological networks.

Intraguild competition and predation have been recognised as important ecological factors influencing the population dynamics of carnivores. The effects of these interactions are often asymmetrical due to a size-related dominancy hierarchy. However, it has been suggested that competitively subordinate carnivores can minimise the costs of predation and competition through spatial and temporal avoidance. Here I investigate the ecological and behavioural mechanisms by which cheetahs (Acinonyx jubatus) coexist with competitively stronger lions (Panthera leo) and spotted hyaenas (Crocuta crocuta). Fieldwork was carried out in the Okavango Delta, northern Botswana, between October 2008 and August 2011. A total of 20 Global Positioning System (GPS) radio-collars were fitted on all known cheetahs (n=6), lion prides (n=5) and spotted hyaena clans (n=6) in the study area (approx. 3 000 km²). Pre-programmed radio-collars recorded locations and activity continuously for each individual and these data were complemented with direct behavioural observations. Cheetah data were analysed with respect to the temporal and spatial likelihood of encountering lions and spotted hyaenas. Results suggest that the response to the risks posed by other predators is species-specific, habitat-specific and dependent on the immediacy of the risk. Resource partitioning was not the main mechanism for coexistence as cheetahs overlapped extensively with lions and spotted hyaenas in time, space and habitat use. Instead, cheetahs adjusted their spatial distribution in response to immediate risks or adapted their habitat use depending on their vulnerability (e.g. behaviours such as feeding or with differing levels of moonlight at night). In general, cheetah temporal and spatial distribution is a hierarchal process, firstly driven by resource acquisition and thereafter fine-tuned by predator avoidance. In addition, habitat heterogeneity seemed to be key in facilitating coexistence. Understanding the behavioural mechanisms that interacting apex predators adopt to regulate these negative interactions could be crucial to carnivore conservation, especially as human-related habitat loss is forcing species into ever smaller areas.