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Spatial Ecology of Coyotes and Cougars: Understanding the Influence of Multiple Prey on the Spatial Interactions of Two PredatorsMahoney, Peter J. 01 May 2017 (has links)
The extent to which predators regulate prey populations remains a subject of debate. Yet, when predator control is employed as a management strategy, it is often assumed that predators can and do regulate prey populations. From 2011 through 2015, I monitored the demography and space use of coyotes (Canis latrans) and cougars (Puma concolor) on Monroe Mountain in Fishlake National Forest, Utah as part of a larger collaboration investigating the impacts of coyote aerial control on mule deer (Odocoileus hemionus) neonate survival. My primary objective was to assess the impacts of anthropogenic regulation on the respective populations and identify any cascading effects relevant to mule deer management. To meet this objective, I established a monitoring program for both predators by deploying radio-telemetry collars (VHF and GPS) on each, documented predation events, established surveys for small mammals and lagomorphs to monitor primary prey populations during deer parturition (June – August), and collected data on the location and demographic composition of winter-removed coyotes. I analyzed these data primarily in a community-based, animal movement and resource selection framework permitting the integration of data from multiple sources. When evaluating coyote aerial removal as a management strategy, I identified a spatial dependency in the ability to match removals with indices of deer recruitment as Wildlife Services Operations personnel were primarily limited by terrain and tree cover. Thus, matching treatment with deer fawning was highly variable with only a small number of sites where removals were effective. In addition, I found that coyotes selected for sites with the highest densities of lagomorphs while avoiding areas with a high probability of encountering cougars. Coyotes did not select for mule deer fawning sites, although individual coyotes that occupied resource-poor home ranges were more likely to do so. Cougars strongly selected for mule deer high use areas throughout much of the year, only switching to elk (Cervus elaphus) during the cougar harvest season (i.e., winter). Data from cougar kill site investigations match the observed patterns in cougar space use. My results suggest that predator-prey processes are multi-dimensional and dynamic through time, which likely contribute to the lack of resolution regarding the efficacy of predator control and the regulatory potential of predators in general.
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The Spatial Ecology of Predator-Prey Interactions: A Case Study of Yellowstone Elk, Wolves, and CougarsKohl, Michel T. 01 May 2019 (has links)
The loss of large apex predators, and their subsequent reintroduction, has been identified as a substantial driver on the structure and function of ecological communities through behavioral mediated trophic cascades (BMTCs). The reintroduction of wolves (Canis lupus) to Yellowstone National Park (YNP) has served as foundational case study of BMTCs. In our system, it has been suggested that wolves have established a ‘landscape of fear’ in which the primary prey, elk (Cervus elaphus), now avoid risky places, which ultimately led to the recovery of the vegetation community. Although this case is frequently cited as a well-understood example of a landscape of fear, researchers never quantified whether elk avoided risky places, a critical component of the BMTC hypothesis. Thus, I employed numerous quantitative approaches to evaluate the role of wolves and cougars on elk habitat selection in northern Yellowstone. The results from this work suggest that the daily activity schedule of wolves provide a temporally predictable period of risk that allows elk to use risky places during safe times. As such, diel predator activity flattened (i.e., made less risky) the landscape of fear for 16 hours per day, 7 days a week, which permitted elk to forage on deciduous woody plants despite the presence of wolves. Thus, suggests that any trophic cascade in northern Yellowstone is likely driven by the consumptive effects of wolves on elk. In addition, my results suggest that daily activity patterns are an important component of predation risk, and as such, provide a predictable avenue for elk to avoid predators despite residing in an environment spatially saturated with wolves and cougars. Thus, the ability of elk to avoid predators through fine-scale spatial decisions provides support for my findings that the current spatial distribution of prey is largely driven by the consumptive effects of predators on the prey population, rather than a landscape of fear. In combination, these results suggest that the landscape of fear, and more generally, fear effects, may be of less relevance to conservation and management than direct killing within free-living, large landscapes.
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Step-Selection Functions for Modeling Animal Movement -- Case Study: African BuffaloAdar, Maia 01 January 2018 (has links)
Understanding what factors influence wildlife movement allows landscape planners to make informed decisions that benefit both animals and humans. New quantitative methods, such as step-selection functions, provide valuable objective analyses of wildlife connectivity. This paper provides a framework for creating a step-selection function and demonstrates its use in a case study. The first section provides a general introduction about wildlife connectivity research. The second section explains the math behind the step-selection function using a simple example. The last section gives the results of a step-selection model for African buffalo in the Kavango Zambezi Transfrontier Conservation Area. Buffalo were found to avoid fences, rivers, and anthropogenic land use; however, there was great variation in individual buffalo's preferences.
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Response of male white-tailed deer (Odocoileus virginianus) to human activity on the landscapeHenderson, Colby 07 August 2020 (has links)
Human activity affects white-tailed deer (Odocoileus virginianus) movement and habitat selection during all times of the year, but knowledge is limited regarding how human risk affects white-tailed deer during the summer and winter. During spring and summer, variation in patch selection varied. Natural vegetation was selected for early in the year, with anthropogenic forages being important for deer use during the summer. During the winter, deer responded to different levels of risk. As hunter risk increased on the landscape, deer altered selection of the landscape. Deer avoided areas that were heavily used by hunters, using areas containing less hunter risk. Use of land cover classifications varied temporally, with cover selected for during the day and forage selected for at night. I have demonstrated that deer respond to human activity on the landscape, by selecting for anthropogenic foraging sources during the spring and summer and avoiding patches that contain risk.
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Cumulative effects of human landscape change, predators, and natural habitat drive distributions of an invasive ungulateDarlington, Siobhan 07 December 2018 (has links)
Human footprint - in which land is converted for human use - is a leading contributor to global habitat and biodiversity loss. The accelerated rate of human landscape change to meet our growing needs has led to the direct loss of critical habitat and shifts in species distributions, interactions, and behaviour. These altered conditions affect species’ ability to adapt to environmental stressors, while some species thrive and others decline. In North America, one ungulate has successfully invaded new habitat in conjunction with human land use – the white-tailed deer. Across the continent, the invasion of white-tailed deer has led to increased competition with other ungulate species including mule deer, moose, and woodland caribou. In regions with abundant apex predators, they have become a source of primary prey as their populations increase. The mechanisms by which deer occupy landscapes in the northern extents of their geographic range are not well studied outside of the winter months, or how deer respond behaviourally to various types of human disturbance in a predator-rich environment.
To address these knowledge gaps, I examined population scale resource selection across seasons and individual movement behaviour in white-tailed deer in northeastern Alberta’s intensively developed oil and gas landscape. I used previously developed models of predator frequency to spatially extrapolate wolf and black bear occurrence across my study region as indicators of indirect predation risk. I used two approaches to habitat modeling to examine deer responses to various modes of human landscape change, including roads, seismic lines, and cut blocks in addition to predators and natural habitat. Deer were best described by cumulative effects – or the combination of all of these factors – across all seasons with proximity to linear features explaining the most variation among the parameters tested. Most prominently in winter, deer strongly selected for habitat features expected to contain abundant natural sources of forage, and linear features, despite a potential increased risk of predation by wolves – suggesting that deer make energetic trade-offs between forage availability and predation risk. At the individual level, deer significantly increased their rate of movement when occupying habitat associated with predation risk. I suggest that deer make greater energetic trade-offs during winter when mobility is limited to evade predators and energetic costs are higher.
The continued use of anthropogenic features post-winter, increased rate of movement and spread of landscape occupancy by deer may allude to the importance of human disturbance in maintaining deer in northern climates. Linear corridors may be an important mechanism by which deer are able to successfully colonize new areas at the northern extents of their range. My results shed light on the drivers of deer distributions in human altered landscapes for managing populations where the invasion of deer is complicit in the decline of other ungulate species such as woodland caribou in Alberta’s boreal forest. / Graduate
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Fine scale habitat and movement patterns of javan slow loris (Nycticebus javanicus) in Cipaganti, West Java, IndonesiaFransson, Lina January 2018 (has links)
Today biodiversity is rapidly decreasing and an increasing number of threatened species live in modified and human dominated landscapes. Therefore it is essential to learn more about how species cope with the changes of their habitat. The focus of this study lies on a primate species, the critically endangered Javan slow loris (Nycticebus javanicus), endemic to the densely populated island of Java, Indonesia. In cooperation with the Little fire face project in West Java, I used a step selection function (SSF) framework, to understand how landscape structure affects the movement of Javan slow lorises within a fragmented mountain-agroforest landscape of Cipaganti, West Java. To investigate the movement and fine scale habitat selection of slow lorises I used one hour locations of 6 radio-collared slow lorises. The habitat and vegetation of observed and random steps was investigated in multiple variables such as presence of food trees and signs of human disturbance. For the analysis I paired observed steps (1h relocations) with 3 random habitat locations and used a conditional logistic regression to parameterize the SSF, which represents the probability of a focal slow loris to select a given step as a function of the habitat and vegetation factors surveyed. In average the slow lorises travelled about 450 m each night and most frequently they used a step length of about 0 – 50 m. My result reveals that slow lorises fine scale habitat selection is positively influenced by the presence of trees and tree trunk cover (indirect increasing the canopy cover and connectivity). They are also to a high extent positively affected by the presence of a feeding tree species, Calliandra calothyrsus. Surprisingly slow lorises selected steps associated with a higher number of fields (fields may indicate an increased biodiversity within the location). The results also indicate that slow lorises are limited in their movement by the presence of fields or rivers, which indicates that slow lorises are negatively influenced in their movement by a declining ability to move and forage within Cipaganti. I found no significant differences between sexes in their distance travelled. The recommendation for future conservation of slow lorises in Cipaganti is to prevent further habitat loss and fragmentation through activities that protect or maintain the present suitable slow loris habitat. Further research is needed to increase the knowledge of these primates’ abilities to live in this modified landscape.
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Advancing our understanding of animal dispersal and functional connectivity in human-altered landscapes: conceptual considerations and their empirical and simulation-based demonstrationPflüger, Femke 17 December 2019 (has links)
No description available.
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Développement d’un modèle centré sur l’individu des déplacements du caribou, du loup et de l’orignal, et de leurs interactions, en forêt boréale aménagéeLatombe, Guillaume 04 1900 (has links)
Le caribou forestier est une espèce menacée au Canada, la principale hypothèse au déclin des populations étant l’intensification de la prédation provoquée par les perturbations anthropiques du paysage. Afin de faire face à cette situation, il est nécessaire d’étudier et comprendre l’impact de l’environnement sur les interactions prédateur-proies entre le caribou et le loup, ainsi qu’avec l’orignal, qui est sa principale proie alternative. Pour cela, cette thèse présente la conception d’un modèle centré sur l’individu des déplacements de ces trois espèces en fonction de leur environnement, dont résulteront les interactions prédateur-proies. Afin de permettre l’application de ce modèle sur de longues périodes, et donc pour un environnement changeant, une méthodologie a été développée, qui s’articule atour de deux aspects principaux. Tout d’abord, la notion de niveaux d’émergence est introduite, permettant d’ordonner les comportements observables du système selon leurs interdépendances, afin de choisir comme trait du modèle un com- portement correspondant au domaine d’applicabilité visé. Ordonner les comportements selon leurs niveaux d’émergence permet également d’identifier la redondance entre les patrons, qui peut être à l’origine d’un phénomène de sur-apprentissage lorsqu’ils sont utilisés lors de la calibration. Dans un second temps, un nouveau protocole pour la calibration et la validation du ou des traits choisis à l’aide des niveaux d’émergence, nommé réplication de système basé sur l’individu (Individual Based System Replication - IBSRtion) est également présenté. Ce protocole met l’emphase sur la modélisation directe, contrairement au principal protocole existant, la modélisation orientée patrons (Pattern Oriented Modelling - POM), et permet une approche empirique en générant artificiellement des données non disponibles ou ne pouvant être récoltées par des études de terrains. IBSRtion a également l’avantage de pouvoir être intégrée dans POM, afin de contribuer à la création d’une méthodologie universelle pour la conception de modèles centrés sur l’individu. Le processus de conception de ce modèle aura entre autre permis de faire une synthèse des connaissances et d’identifier certaines lacunes. Une étude visant à palier le manque de connaissances satisfaisantes sur les réponses comportementales à court-terme des proies face au risque de prédation a notamment permis d’observer que celles-ci sont une combinaison de comportements chroniques et éphémères, et que les mécanismes qui en sont à l’origine sont complexes et non-linéaires. Le résultat de ce travail est un modèle complexe utilisant de nombreux sous-modèles, et calibré de façon empirique, applicable à une grande variété d’environnements. Ce modèle a permis de tester l’impact de l’enfeuillement sur les relations prédateur-proies. Des simulations ont été effectuées pour différentes quantités d’enfeuillement, suivant deux configurations spatiales différentes. Les résultats de simulation suggèrent que des plans d’aménagement considérant également l’habitat de l’orignal pourraient être bénéfiques pour le caribou forestier, car ils permettraient d’améliorer la ségrégation spatiale entre les deux espèces, et donc entre le caribou et le loup. En le couplant avec un module de naissances et de morts naturelles ainsi qu’un modèle d’évolution du paysage, ce modèle permettra par la suite d’évaluer l’impact de plans d’aménagement forestier sur la viabilité des populations de caribou forestier. / Forest-dwelling woodland caribou are considered threatened in Canada. The main hypothesis to the decrease of populations is the intensification of predation provoked by anthropogenic perturbations in the landscape. To deal with this situation, it is necessary to study and to understand the impact of the environment on the predator-prey interactions between the caribou and the wolf, and with the moose, its main alternative prey. In this perspective, this thesis presents the design of an individual-based model of displacements of these three species with respect to their environment, from which the predator-prey interactions will result. To allow for the application of this model for long periods of time, i.e. for changing environments, a methodology has been developed, which is based on two key points. First, the notion of levels of emergence is introduced, allowing to order the different observable comportments of the system according to their inter-dependencies, to help with choosing a trait of the model corresponding to the intended domain of applicability. Ordering the comportments according to their levels of emergence also permits to identify redundancy between patterns, which can lead to over-fitting when they are used for calibration. Second, a new methodology for calibration and validation of the trait(s) chosen by means of the levels of emergence framework is also presented, named Individual Based System Replication (IBSRtion). This protocol emphasizes forward modelling, contrary to the main existing methodology, Pattern Oriented Modelling (POM), and allows to use an empirical approach by artificially generating data that are unavailable or that cannot be obtained by means of field studies. IBSRtion can also be integrated into POM, to contribute to the establish- ment of a universal methodology for the design of individual based models. The design process of this model allowed for a synthesis of existing knowledge and to point out some gaps. More specifically, a study conducted to deal with the lack of sufficient information on the short-term response of prey to predation risk allowed to observe that their behavioural responses to prior presence of predators are a combination of chronic and ephemeral behaviours, and that the mechanisms that produce them are complex and non-linear. The outcome of this work is a complex model, using many sub-models, and calibrated in an empirical fashion, that can be applied to a wide variety of environments. This model allowed to test the impact of the encroachment of deciduous trees on predator-prey relations. Simulations have been run for different quantities of encroachment, according to two different spatial configurations. Simulation results suggest that management plans taking into account the moose’s habitat might benefit woodland caribou, because they could increase spatial segregation between the two species, and thus between caribou and wolf. Coupling this model with a module of birth and natural death, along with a model of landscape transformation, would allow the assessment of the impact of different forest management plans on the viability of woodland caribou populations.
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Développement d’un modèle centré sur l’individu des déplacements du caribou, du loup et de l’orignal, et de leurs interactions, en forêt boréale aménagéeLatombe, Guillaume 04 1900 (has links)
Le caribou forestier est une espèce menacée au Canada, la principale hypothèse au déclin des populations étant l’intensification de la prédation provoquée par les perturbations anthropiques du paysage. Afin de faire face à cette situation, il est nécessaire d’étudier et comprendre l’impact de l’environnement sur les interactions prédateur-proies entre le caribou et le loup, ainsi qu’avec l’orignal, qui est sa principale proie alternative. Pour cela, cette thèse présente la conception d’un modèle centré sur l’individu des déplacements de ces trois espèces en fonction de leur environnement, dont résulteront les interactions prédateur-proies. Afin de permettre l’application de ce modèle sur de longues périodes, et donc pour un environnement changeant, une méthodologie a été développée, qui s’articule atour de deux aspects principaux. Tout d’abord, la notion de niveaux d’émergence est introduite, permettant d’ordonner les comportements observables du système selon leurs interdépendances, afin de choisir comme trait du modèle un com- portement correspondant au domaine d’applicabilité visé. Ordonner les comportements selon leurs niveaux d’émergence permet également d’identifier la redondance entre les patrons, qui peut être à l’origine d’un phénomène de sur-apprentissage lorsqu’ils sont utilisés lors de la calibration. Dans un second temps, un nouveau protocole pour la calibration et la validation du ou des traits choisis à l’aide des niveaux d’émergence, nommé réplication de système basé sur l’individu (Individual Based System Replication - IBSRtion) est également présenté. Ce protocole met l’emphase sur la modélisation directe, contrairement au principal protocole existant, la modélisation orientée patrons (Pattern Oriented Modelling - POM), et permet une approche empirique en générant artificiellement des données non disponibles ou ne pouvant être récoltées par des études de terrains. IBSRtion a également l’avantage de pouvoir être intégrée dans POM, afin de contribuer à la création d’une méthodologie universelle pour la conception de modèles centrés sur l’individu. Le processus de conception de ce modèle aura entre autre permis de faire une synthèse des connaissances et d’identifier certaines lacunes. Une étude visant à palier le manque de connaissances satisfaisantes sur les réponses comportementales à court-terme des proies face au risque de prédation a notamment permis d’observer que celles-ci sont une combinaison de comportements chroniques et éphémères, et que les mécanismes qui en sont à l’origine sont complexes et non-linéaires. Le résultat de ce travail est un modèle complexe utilisant de nombreux sous-modèles, et calibré de façon empirique, applicable à une grande variété d’environnements. Ce modèle a permis de tester l’impact de l’enfeuillement sur les relations prédateur-proies. Des simulations ont été effectuées pour différentes quantités d’enfeuillement, suivant deux configurations spatiales différentes. Les résultats de simulation suggèrent que des plans d’aménagement considérant également l’habitat de l’orignal pourraient être bénéfiques pour le caribou forestier, car ils permettraient d’améliorer la ségrégation spatiale entre les deux espèces, et donc entre le caribou et le loup. En le couplant avec un module de naissances et de morts naturelles ainsi qu’un modèle d’évolution du paysage, ce modèle permettra par la suite d’évaluer l’impact de plans d’aménagement forestier sur la viabilité des populations de caribou forestier. / Forest-dwelling woodland caribou are considered threatened in Canada. The main hypothesis to the decrease of populations is the intensification of predation provoked by anthropogenic perturbations in the landscape. To deal with this situation, it is necessary to study and to understand the impact of the environment on the predator-prey interactions between the caribou and the wolf, and with the moose, its main alternative prey. In this perspective, this thesis presents the design of an individual-based model of displacements of these three species with respect to their environment, from which the predator-prey interactions will result. To allow for the application of this model for long periods of time, i.e. for changing environments, a methodology has been developed, which is based on two key points. First, the notion of levels of emergence is introduced, allowing to order the different observable comportments of the system according to their inter-dependencies, to help with choosing a trait of the model corresponding to the intended domain of applicability. Ordering the comportments according to their levels of emergence also permits to identify redundancy between patterns, which can lead to over-fitting when they are used for calibration. Second, a new methodology for calibration and validation of the trait(s) chosen by means of the levels of emergence framework is also presented, named Individual Based System Replication (IBSRtion). This protocol emphasizes forward modelling, contrary to the main existing methodology, Pattern Oriented Modelling (POM), and allows to use an empirical approach by artificially generating data that are unavailable or that cannot be obtained by means of field studies. IBSRtion can also be integrated into POM, to contribute to the establish- ment of a universal methodology for the design of individual based models. The design process of this model allowed for a synthesis of existing knowledge and to point out some gaps. More specifically, a study conducted to deal with the lack of sufficient information on the short-term response of prey to predation risk allowed to observe that their behavioural responses to prior presence of predators are a combination of chronic and ephemeral behaviours, and that the mechanisms that produce them are complex and non-linear. The outcome of this work is a complex model, using many sub-models, and calibrated in an empirical fashion, that can be applied to a wide variety of environments. This model allowed to test the impact of the encroachment of deciduous trees on predator-prey relations. Simulations have been run for different quantities of encroachment, according to two different spatial configurations. Simulation results suggest that management plans taking into account the moose’s habitat might benefit woodland caribou, because they could increase spatial segregation between the two species, and thus between caribou and wolf. Coupling this model with a module of birth and natural death, along with a model of landscape transformation, would allow the assessment of the impact of different forest management plans on the viability of woodland caribou populations.
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