The spatial and population dynamics of avian scavengers are poorly understood. This information is key for management and conservation interventions that guarantee long-term species conservation. My goal in this dissertation is to fill information gaps on the movement ecology of New World vultures using the Turkey Vulture (Cathartes aura) as a model species. I used a continental-wide satellite telemetry dataset to study the migration ecology, space-use, and demography of the three North American breeding populations of Turkey Vultures wintering in the Neotropics during a 17-year period. I found that primary productivity, but not weather, triggered Turkey Vulture migratory behavior, migration initiated when primary productivity dropped at the end of the breeding and non-breeding season. Migratory connectivity was high at the species level (0.85, 95% CI: 0.74–0.94). However, I found evidence of intrapopulation segregation during the non-breeding season demonstrated by lower values of migratory connectivity in each population. I investigated how seasonality interacted with human disturbance, landscape composition and configuration to mediate patterns of geographic and environmental space-use, and annual and seasonal survival probabilities. Environmental space-use was best explained by landscape configuration. Geographic space-use exhibited a quadratic response to landscape configuration metrics, suggesting that Turkey Vultures maximize space-use in landscape with intermediate disturbance. Human disturbance, but not but not landscape composition and configuration, influenced survival rates in space and time. Overall annual survival averaged 0.87 (95% CI = 0.74 – 0.98). Mortality risk was low in western and central populations but was 3.7 times greater for vultures in the eastern population. Risk of mortality for all vulture populations increased with road density, and this was greater during the non-breeding and return migration seasons. My results suggest that spatial and population dynamics are affected at a continental scale by the energy landscape, intermediate disturbance and human disturbance. My dissertation emphasizes the importance of an integrative empirical-modeling approach to address questions on effects of resources availability and search efficiency in the spatial and population dynamics of avian scavengers.

Our thesis project consists of three architectural interventions: The Mushroom, The Gnat and The Snake, fitting into a vision of a Swedish forest managed in a more sustainable way. A future in which the practice of clear-felling has been abandoned in favor of alternative methods falling under the umbrella term Continuous Cover Forestry (CCF). As the biological aspects of forestry is not our area of expertise, we have investigated what this reorganization at large would mean for the Swedish landscape, economy and society. Where it becomes a question for architecture. When the timber industry looses its hegemony over the forest, the forest becomes available to different uses. For life and recreation, and for the production of forest goods other than timber, such as wild game meat, berries, and mushrooms. These activities are able to take place within the same space as forestry, thereby overcoming the spatial separation of functions we see today. Our interventions work by docking onto different points of today’s logistics flow, in order to later replace them. They take into account more of the different values and users of the forest which we have identified. The project follows the flow of goods from the forest as they make their way towards the larger markets. The Mushroom is an outpost in the middle of the productive forest which supplies the surrounding area with the necessary infrastructure in order to extract goods from it, doubling as a recreational dwelling. One of these can be placed every 30 km. The Gnat is a tower structure containing multiple different functions ranging from marking the pick-up spot for the harvested timber, functioning as a hunting tower, shelter and storage. Many of them are placed along forest roads. The Snake is a local processing plant managing small-scale refinement of the goods of the forest close to their site of harvest, thus channeling some of the economical flow back to the communities living of the forest. Together they form a complete series of infrastructure demonstrating how we could organize the future Swedish forest.

Animal behaviours are demonstrably governed by sensory stimulation, previous experience and internal states like hunger. With increasing hunger, priorities shift towards foraging and feeding. During foraging, flies are known to employ efficient path integration strategies. However, general long-term activity patterns for both hungry and satiated flies in conditions of foraging remain to be better understood. Similarly, little is known about how permanent contact chemosensory stimulation affects locomotion. To address these questions, we have developed a novel, simplistic fly activity tracking setup— the Panopticon. Using a 3D-printed Petri dish inset, our assay allows recording of walking behaviour, of several flies in parallel, with all arena surfaces covered by a uniform substrate layer. We tested two constellations of providing food: (i) in single patches and (ii) omnipresent within the substrate layer. Fly tracking is done with FIJI, further assessment, analysis and presentation is done with a custom-built MATLAB analysis framework. We find that starvation history leads to a long-lasting reduction in locomotion, as well as a delayed place preference for food patches which seems to be not driven by immediate hunger motivation.

Exotic invasive plant species can alter aquatic habitats potentially influencing the macroinvertebrate community and foraging fishes. Therefore, I investigated the hypothesis that Hydrilla verticillata will alter habitat important to macroinvertebrate community structure and bluegill foraging efficiency. Studies were conducted in ponds and aquaria. At the pond level, macroinvertebrate abundance, richness, and biomass in a hydrilla-dominated habitat did not differ significantly from a diverse plant habitat. Indicator taxa did differ significantly between respective treatments. The data suggest hydrilla beds may not provide increased macroinvertebrate abundance and richness compared to diverse plant beds as previously thought. In aquaria, habitat complexity (Ihv) and light transmittance were influenced by increasing the homogeneity of hydrilla in an aquatic bed habitat. In addition, bluegill foraging efficiency was affected negatively by increasing spatial complexity of a hydrilla dominated habitat. Therefore, a shift to a monotypic hydrilla habitat can alter macroinvertebrate community composition and impact bluegill foraging success.

The goal of this thesis is to identify differences and consistencies in the trajectories taken by foraging agents before and after they have learned the location of a target. The challenge is that these agents do not go directly towards the target after learning and keep a certain amount of randomness in their paths. We use different versions of discrete curvature and head angle as tools in this analysis. We also build models of foraging agents using stochastic processes with data supported parameters.

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