Thesis (M. S.)--Oklahoma State University, 2004. / Vita. Includes bibliographical references (p. 29-32).

Thesis (Ph.D.)--Indiana University, School of Public and Environmental Affairs, 2007. / Source: Dissertation Abstracts International, Volume: 68-10, Section: B, page: 6564. Adviser: Vicky Meretsky. Title from dissertation home page (viewed May 20, 2008).

Thesis (Ph.D.)--Indiana University, Dept. of Anthropology, 2005. / Source: Dissertation Abstracts International, Volume: 67-01, Section: A, page: 0232. Adviser: Patrick J. Munson. "Title from dissertation home page (viewed Dec. 12, 2006)."

Mesocarnivores occupy critical functional roles in regulating ecosystems and maintaining biodiversity. In the Canadian Rocky Mountains, mustelid species depend heavily on carrion as an important dietary contribution, particularly in winter when resources are scarce. In diverse mesocarnivore communities such as this, sympatric species must balance energetic resource acquisitions through scavenging with avoidance of costly competition dynamics, in a manner that optimizes energetic gain through risk aversion. We examined the nature of spatial-temporal interactions between wolverine (Gulo gulo), American marten (Martes Americana), and short-tailed weasel (Mustela erminea) in the Willmore Wilderness Park in western Alberta. Data were collected from camera traps (n = 59) baited with a simulated scavenging opportunity during winter months between 2006 to 2008. The spatial-temporal dimensions of intraguild competition were evaluated using a multi-model approach. Zero-inflated negative binomial (ZINB) or zero-inflated Poisson (ZIP) regression models were used to identify the competitive and environmental factors that affected (1) species presence/absence and (2) how intensely a species would spatiotemporally optimize a carrion site. A time-to-event analysis was used to quantify the directionality of fine-scale (hourly) reactionary behavioural responses of species to potential sources of competition. An extension of this group of models, the Cox proportional hazard (CPH) model was used to further reveal the relative influence of external environmental variables (i.e. diel period, landcover, and snow depth) on temporal spacing. Pairing CPH and ZINB/ZIP models enables us to recognize the relative contribution of fine-scale spatial and temporal behavioural responses to competitors in shaping coexistence strategies. Our results suggest that facultative scavengers adopt different coexistence mechanisms based on the interspecific competitor and environmental conditions they encounter at carrion sites. We found that carrion use was impacted for all species by competition and snow depth. Marten scavenging behaviours were additionally impacted by habitat character. We also found evidence of fine-scale temporal attraction between marten and wolverine, thought to indicate a shared net-energetic gain at scavenging sites. Our results suggest that mesocarnivore scavengers are likely to adopt spatiotemporal mechanisms to facilitate carrion resource partitioning and adapt to conditions specific to carcass placement in a spatially complex environment. Given their vital ecological roles, it is important that we recognize the ability of individual mustelid species to exploit scavenging opportunities and identify the external factors that influence coexistence. Understanding the factors that drive access to these ephemeral resources will provide valuable information for anticipating impacts of climate change on facultative scavengers in the boreal forests of western Canada. / Graduate / 2022-08-23

Unravelling the complexities of a disease with multiple wildlife host and multiple tsetse vector species is no easy task. After over a century of field observations, experimental studies, anecdotal evidence and conjecture, the role of wildlife in the transmission of trypanosomes is still unclear. Recently, however, frameworks used in the studies of other vector-borne diseases with wildlife reservoirs showed that not only is it possible to understand transmission, but that spatio-temporal predictions of human disease risk and targeted control are realistic aims, even in such complex systems. This thesis explores the epidemiology of human African trypanosomiasis (HAT) in the Serengeti-Mara ecosystem in Northern Tanzania, where recent cases in tourists have highlighted the disease as a public health and economic concern. Assessment of the prevalence of trypanosome infections in different wildlife species is the first step in investigating the relative importance of different species in disease transmission. Identification of trypanosomes relies on sensitive and specific diagnostic tests. Polymerase chain reaction (PCR) protocols based on interspecies differences in the length of the ribosomal internal transcribed spacer (ITS) regions have been widely used in livestock to identify multiple trypanosome species in one PCR reaction. This study represents the first assessment of these protocols on blood samples collected from wildlife. Clonal sequence analysis of PCR products revealed a large range of trypanosomes circulating in wildlife, including Trypanosoma congolense, Trypanosoma brucei, Trypanosoma simiae Tsavo, Trypanosoma godfreyi and Trypanosoma vivax. In addition sequences similar to known sequences, termed Trypanosoma simiae-like and T. vivax-like trypanosomes, may reflect further diversity. However, further characterisation is needed before ITS protocols can be used widely for epidemiological studies in wildlife. The prevalence of T. brucei s.l. and T. congolense varied widely between species. This variation was predominantly explained by taxonomic classification, suggesting intrinsic differences in response to trypanosomes. Trypanosoma brucei rhodesiense, the subspecies responsible for HAT, was identified in lion, hyaena and reedbuck. Age significantly affected the prevalence of T. congolense in lion and hyaena, with the highest prevalence in subadults. The lack of statistically significant differences in prevalence between animals sampled live or after death confirmed that post-mortem sampling provides a method for increasing sample sizes in wildlife studies. The complex relationship between tsetse density and prevalence of trypanosome infections illustrated the difficulties of assessing data from diverse ecosystems with many potential confounding factors. A cross-sectional study of Glossina swynnertoni and Glossina pallidipes, the main tsetse species in Serengeti, highlighted the difficulties of integrating the results of microscopy and PCR to generate meaningful measures of the prevalence of transmissible T. brucei infections for epidemiological studies. However, PCR results suggested that G. pallidipes may be more important as a vector of T. brucei s.l. than has been previously recognised. Spatial variation in both tsetse density and the prevalence of trypanosome infections suggests human disease risk is heterogeneous. The results of this study, along with relevant literature, are considered within the context of frameworks used for other vector-borne diseases and the implications for disease management discussed.

Thesis (Ph.D.)--Indiana University, School of Public and Environmental Affairs, 2006. / "Title from dissertation home page (viewed July 11, 2007)." Source: Dissertation Abstracts International, Volume: 67-08, Section: B, page: 4319. Adviser: Vicky J. Meretsky.

Human population growth and development reduce the area and quality of natural communities and lead to a reduction of populations of the species associated with them. Certain species can be useful indicators or "focal species" for determining the quality of ecosystem remnants and the required management practices. Tree squirrels are good models for studies on the effects of fragmentation because they depend on mature forests. The Big Cypress fox squirrel, (Sciurus niger avicennia), a state-listed Threatened subspecies endemic to south Florida, appears sensitive to habitat fragmentation and fire regime. This research aims to assess the conservation status of the Big Cypress fox squirrel. I documented the current distribution of the fox squirrel by obtaining and mapping occurrence records and through interviews with biologists and other field personnel of public land-managing agencies, and private landowners including golf course managers. Transect sampling was used to survey and sample natural areas and private lands to evaluate the distribution, abundance, and habitat use of fox squirrels. Natural areas and suburban areas appear to support Big Cypress fox squirrels, but individuals are widely distributed and only found in low numbers throughout southwest Florida. The distribution of fox squirrel populations depends on land use and understory height, but not the size of trees. Fire suppression has resulted in a dense understory in large portions of parks and preserve lands, which is unsuitable for fox squirrels.

Scientists are now able to collect ubiquitous data on individual-level movement at increasingly fine spatial and temporal resolutions. Despite this surge in data availability, methods for extracting relevant information about spatial-temporal movement patterns remain limited in scope and sophistication. The objective of this PhD research is to develop novel quantitative approaches for analyzing spatial-temporal patterns in modern movement datasets. A review of the state-of-the-art in quantitative movement analysis identifies the current breadth of available methods, while highlighting key limitations and fragmentation in the literature across multiple disciplines. Existing theory from the geographical literature, namely time geography is applied to a novel application – wildlife movement ecology (termed the PPA home range), in an attempt to expose these ideas to wildlife researchers. The PPA home range method has several advantages over existing methods, most notably its ability to identify omission and commission error in existing home range techniques. Next, an advance to time geography theory is proposed for incorporating object kinetics (i.e., velocity and acceleration) into a probabilistic movement model termed kinetic-based probabilistic time geography. Kinetic-based probabilistic time geography provides a more accurate model for predicting object movement when object kinetics are relevant (e.g., with fast moving vehicles, or athletes). A novel method (termed the DI index) for quantifying dynamic interactions between moving objects is presented, focusing specifically on examining cohesive movement behaviour. The DI index is advantageous over existing dynamic interaction measures in that it is computed at the local level, facilitating a finer treatment of interactive movement behaviour. The DI index is then contrasted with seven alternative measures of dynamic interaction to examine the effectiveness of each at identifying expected and unexpected interactive behaviour, at a range of sampling resolutions, in the context of wildlife movement ecology. The results highlight the value of the DI index, especially as a local level index, capable of identifying variable and infrequent interactions in pairs of moving objects. In summary, this dissertation contributes to the rapidly expanding body of quantitative movement research by providing: 1) a cross-disciplinary methodological review, 2) expanding the application of core time geography theory to wildlife ecology, 3) advancing time geographic theory in development of kinetic-based probabilistic time geography, 4) developing a novel index (the DI index) for measuring inter-object interactions, and 5) examining the effectiveness of available dynamic interaction measures, and their sensitivity across sampling resolutions, in the context of wildlife ecology. / Graduate / 0366 / 0463 / 0329

Animal home range estimations are important for conservation planning and protecting the habitat of threatened species. The accuracy of home range calculations is influenced by the map projection chosen in a geographic information system (GIS) for data analysis. Different methods of projection will distort spatial data in different ways, so it is important to choose a projection that meets the needs of the research. The large number of projections in use today and the lack of distortion comparison between the various types make selecting the most appropriate projection a difficult decision. The purpose of this study is to quantify and compare the amount of area distortion in animal home range estimations when projected into a number of projected coordinate systems in order to understand how the chosen projection influences analysis. The objectives of this research are accomplished by analyzing the tracking data of four species from different regions in North and South America. The home range of each individual from the four species datasets is calculated using the Characteristic Hull Polygon method for home range estimation and then projected into eight projected coordinate systems of various scales and projection type, including equal area, conformal, equidistant, and compromise projections. A continental Albers Equal Area projection is then used as a baseline area for the calculation of a distortion measurement ratio and magnitude of distortion statistic. The distortion measurement ratio and magnitude calculations provide a measurement of the quantity of area distortion caused by a projection. Results show the amount distortion associated with each type of projection method and how the amount of distortion changes for a projection based on geographic location. These findings show how the choice of map projection can have a large influence on data analysis and illustrate the importance of using an appropriate PCS for the needs of a given study. Distorted perceptions can influence decision-making, so it is important to recognize how a map projection can influence the analysis and interpretation of spatial data.

Mounting evidence suggests that large carnivores regulate the abundance and diversity of species at multiple trophic levels through cascading top-down effects. The fear large carnivores inspire in their prey may be a critical component of these top-down effects, buffering lower trophic levels from overconsumption by suppressing large herbivore and mesopredator foraging. However, the evidence that the fear of large carnivores cascades through food webs has been repeatedly challenged because it remains experimentally untested. My collaborators and I exploited a natural experiment – the presence or absence of mesopredator raccoons (Procyon lotor) on islands in the Gulf Islands of British Columbia, Canada – to examine the breadth of mesopredator impacts in a system from which all native large carnivores have been extirpated. By comparing prey abundance on islands with and without raccoons, we found significant negative effects of raccoon presence on terrestrial (songbirds and corvids), intertidal (crabs and fish) and shallow subtidal (red rock crabs Cancer productus) prey, demonstrating that, in the absence of native large carnivores, mesopredator impacts on islands can extend across ecosystem boundaries to affect both terrestrial and marine communities. To test whether fear of large carnivores can mitigate these community-level impacts of mesopredators, we experimentally manipulated fear in free-living raccoon populations using month-long playbacks of large carnivore vocalizations and monitored the effects on raccoon behaviour and the intertidal community. Fear of large carnivores reduced raccoon foraging to the benefit of the raccoon’s prey, which in turn affected a competitor and prey of the raccoon’s prey. By experimentally restoring the fear of large carnivores in our study system, we succeeded in reversing the impacts of raccoons, reinforcing the need to protect large carnivores given the conservation benefits the fear of them provides. Our experimental work demonstrated that fine-scale behavioural changes in prey in response to predation risk can have community-level effects relevant to biodiversity conservation. However, experimentally testing animal responses to predators and other sources of risk in free-living wildlife presents considerable logistical challenges. To address these challenges, my collaborators and I developed an Automated Behavioural Response system, which integrates playback experiments into camera trap studies, allowing researchers to collect experimental data from wildlife populations without requiring the presence of an observer. Here I describe tests of this system in Uganda, Canada and the USA, and discuss novel research opportunities in ecology and conservation biology made available by this new technology. / Graduate