Graduate Theses & Dissertations

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Selection on functional genes across a flying squirrel (genus Glaucomys) hybrid zone
While hybridization between distinct taxa can have undesirable implications, it can also result in increased genetic variability and potentially, the exchange of adaptive genes or traits. Adaptive variation acquired through introgressive hybridization may be particularly advantageous for species facing rapid environmental change. I investigated a novel, climate change-induced hybrid zone between two flying squirrel species: the southern (Glaucomys volans) and northern (G. sabrinus) flying squirrel. I was interested in the occurrence of hybridization and introgression, the type of selective pressures maintaining the hybrid zone and the potential for adaptive introgression. I found relatively low hybridization and introgression frequencies (1.7% and 2.9% of the population, respectively) and no evidence of selection on hybrids or backcrosses in particular environments. I conclude that the data are more consistent with a hybrid zone maintained by endogenous (environment-independent) selection. I tested for adaptive introgression using two functional genes: IGF-1 and CLOCK. I documented intermediate functional allele frequencies in backcrosses compared to parental populations, suggesting the alleles do not confer fitness advantages in backcrosses. Despite lack of evidence for current adaptive introgression, genetic admixture between G. volans and G. sabrinus may provide adaptive potential should these species face more rapid or drastic environmental change in the future. Author Keywords: adaptive introgression, flying squirrel, Glaucomys sabrinus, Glaucomys volans, hybridization, introgression
Longitudinal trends of benthic invertebrates in regulated rivers
The Serial Discontinuity Concept describes the downstream recovery of key biophysical variables below an impoundment. With the proliferation of hydropower dams to meet increasing societal demands, further refinement and understanding of the Serial Discontinuity Concept is needed to accurately predict downstream impacts and ensure the proper management of rivers. In this study, I examine SDC predictions on physical, chemical and biological recovery in regulated rivers providing evidence from 1) a comprehensive literature review and 2) a formal test using two regulated rivers in Northern Ontario. I specifically address how these changes are reflected in benthic invertebrate abundance, diversity, and community composition. The literature review and case studies support the predicted recovery of temperature, periphyton, substrate, and drift. In addition, the study suggests that two recovery gradients exist in regulated rivers: 1) a longer, thermal gradient taking up to hundreds of kilometres downstream; and 2) a shorter, resource subsidy gradient recovering within 1-4 km downstream of an impoundment. Total benthic invertebrate abundance varies considerably and depends on the degree of flow alteration and resource subsidies from the upstream reservoir. In contrast, benthic diversity is reduced below dams irrespective of dam location and operation with little recovery observed downstream. Contrary to SDC predictions, the longitudinal gradient in regulated rivers is not a compaction of functional changes seen over several stream orders in natural rivers but a response to dam design and reservoir conditions. Stoneflies and dragonflies are particularly sensitive to regulation while filter feeding invertebrates are enhanced. Ward and Stanford's (1983) Serial Discontinuity Concept is still a useful framework for testing hypotheses. Future studies should further expand the SDC through empirical estimation within the context of the landscape to gain a better scientific understanding of regulated river ecology. Author Keywords: benthic invertebrates, dams, longitudinal, recovery, River Continuum Concept, Serial Discontinuity Concept
Songs We Share (and the Records We Steal)
This thesis explores the rhetoric of theft imposed on online music by comparing file sharing to shoplifting. Since the litigation between the music industry and Napster, file sharing has been perceived, both by the entertainment industry and by a music listening public, as a criminal act. However, file sharing has more in common with home taping and music archives than it does with music shoplifting. It differs from theft in terms of law, motivation and publicness. In reviewing three histories -- a history of petty theft, a history of policing online music, and a history of shoplifting narratives in popular music culture -- the implications for the cultural production of popular music and popular music identity become apparent. In the end, file sharing links itself more to parody and the concept of fairness than it does to youth rebellion and therefore is unsuitable for sustaining a traditional music industry and the values it has formed with its public. Author Keywords: copyright, cultural production, file sharing, mp3, popular music, shoplifting
Spatial dynamics of pollination in dioecious Shepherdia canadensis in Yukon, Canada
Sexual reproduction in flowering plants depends on investment in reproduction, the mode of pollen transfer, the availabilities of nutrient resources and potential mates, and the spatial scales over which these processes take place. In this thesis, I studied the general reproductive biology of Shepherdia canadensis (L.) Nutt. (Elaeagnaceae) and the suite of pollinators that visit the plants in Ivvavik National Park, Yukon, Canada. Across ten sites, I found that S. canadensis females were larger than males, but males produced more flowers than females at most sites. Males typically occurred at higher frequencies than females with the average male to female sex ratio being 1.19 ± 0.08 (mean ± SE, n = 10 sites). Both shrub size and flower production were significantly influenced by interactions between soil nitrogen and sex. Insect visitors to S. canadensis flowers were primarily ants and flower flies (Syrphidae), but exclusion experiments indicated that visitation by flying insects yielded greater fruit production than visitation by crawling insects. I found that fruit set was limited by the density of males within populations, but only over small distances (4-6 m). This is the first study to demonstrate that female reproductive success of a generalist-pollinated dioecious plant is limited by the density of males over small spatial scales. Author Keywords: dioecy, pollinators, sex ratio, sexual dimorphism, Shepherdia canadensis
THE EFFECTS OF ROTATIONAL GRAZING AND HAY MANAGEMENT ON THE REPRODUCTIVE SUCCESS OF BOBOLINK AND EASTERN MEADOWLARK IN EASTERN ONTARIO
I investigated the impact of beef-cattle farm management on the reproductive success of Bobolink (Dolichonyx oryzivorus) and Eastern Meadowlark (Sturnella magna) within Eastern Ontario. I monitored rotational grazing management regimes and hay cut dates while assessing breeding phenology and reproductive success of Bobolinks and Eastern Meadowlarks. In pasture paddocks the major factor determining Bobolink reproductive success was the date that cattle entered a paddock to graze, with earlier entries resulting in lower reproductive success. On a landscape scale, within a series of paddocks grazed by a single herd, as the number of paddocks grazed during the nesting season increased, the number of Bobolinks that reproduced successfully decreased. Experimental quantification of trampling showed that cattle exposure to clay pigeon targets, regardless of stocking rates, resulted in the majority of targets being trampled. In hayfields associated with beef- cattle operations, grassland birds had a higher likelihood of success when cutting occurred after 4 July. The best method to improve the reproductive success of Bobolinks and Eastern Meadowlarks is to leave some hayfields and pasture paddocks undisturbed until nesting is complete. Author Keywords: Bobolink, Dolichonyx oryzivorus, farm management, hayfield, pasture, rotational grazing
USE OF SALIVARY CORTISOL TO EVALUATE THE INFLUENCE OF RIDES ON THE STRESS PHYSIOLOGY OF DROMEDARY CAMELS (CAMELUS DROMEDARIUS)
Many facilities attempt to alleviate the risk of chronic stress in captivity by providing environmental enrichment shown to minimize behavioural disorders and stress in several species. One potential form of enrichment used in zoos is training animals to perform rides for guests, however, the effect of this activity on the welfare of individual animals has never been examined. I validated the use of saliva for assessing stress in dromedary camels (Camelus dromedarius) an animal commonly used for rides. I then measured variation in salivary cortisol in four male camels during animal rides for guests at the Toronto Zoo. The camels were sampled during the ride season (from June to August) using four treatments: 1) in their pasture, 2) at the ride area not performing rides, 3) performing a low number of rides (n=50/day) and 4) performing a high number of rides (n=150/day). Furthermore, samples were taken before and after the ride season for comparison. There was a significant difference between the post-ride season treatment and the three treatments involving guest presence during the ride season (ride area, low rides, high rides. This indicates that performing rides is not a stressful experience based on the stress metrics I used, and suggests that rides may be a form of enrichment for dromedary camels. Author Keywords: ACTH challenge, animal welfare, camels, environmental enrichment, salivary cortisol, stress
Sinaakssin (writing/picture)
Assimilative policies limit and disrupt the inclusion of Aboriginal values in most Aboriginal services today. This art-based, qualitative research study approaches that issue, and using symbolism and story a sample scenario was created to demonstrate the impact of assimilative policy on Aboriginal service delivery in a storyboard format. The storyboard was then presented to four traditional thinkers who contemplated the issues therein, and as they deconstructed, considered, and conferred they resolved the matter and produced four distinct models. Imagery is relied on as a traditional means of communication to capture and convey the research issue as a painted story. This research tested the viability of using imagery as a storyboard methodology for solving social issues. By using this approach this dissertation sought to answer the question, does Indigenous knowledge have the power to change the systemic structures that surround our services. For the analysis, did the three Indigenous knowledge paradigms effectively assist in determining the nature of the Indigenous knowledge applied? Author Keywords: collective community subjectivity, Indigenous methodology, paradigms, story, symbolic communication, symbolic representation
Pausing Encounters with Autism and Its Unruly Representation
This dissertation seeks to explore and understand how autism, asperger and the autistic spectrum is represented in Canadian culture. Acknowledging the role of films, television, literature and print media in the construction of autism in the consciousness of the Canadian public, this project seeks to critique representations of autism on the grounds that these representations have an ethical responsibility to autistic individuals and those who share their lives. This project raises questions about how autism is constructed in formal and popular texts; explores retrospective diagnosis and labelling in biography and fiction; questions the use of autism and Asperger's as metaphor for contemporary technology culture; examines autistic characterization in fiction; and argues that representations of autism need to be hospitable to autistic culture and difference. In carrying out this critique this project proposes and enacts a new interdisciplinary methodology for academic disability study that brings the academic researcher in contact with the perspectives of non-academic audiences working in the same subject area, and practices this approach through an unconventional focus group collaboration. Acknowledging the contribution of disability studies approaches to representation, this project will also challenge these methodologies on the grounds that the diverse voices of audiences are, at times, absent from discourse focused research. Chapter One offers an explanation of disability studies scholarship and the history of autism as a category of disability and difference. Chapter Two looks at how disability and specifically autistic representations have been understood academically and introduces the rationale and experiences of the focus group project. Chapter Three explores retrospective, biographical diagnosis, the role of autism as technological metaphor, and contemporary biography. Chapter Four looks at the construction of autistic characters in Canadian literature and film. Chapter Five interrogates documentary and news media responses to autism and the construction of autism as Canadian health crisis, and also explores how discourses that surround autism are implicated in interventions and therapeutic approaches to autistic individuals. Key Terms Autism; Autistic Spectrum; Asperger; Disability; Representation; Media; Interdisciplinary Research; Focus Group; Retrospective Diagnosis; Biography; Academic Method; Academic and Representational Responsibility; Literature; Film; Diagnosis; Disability Studies; Therapy Author Keywords: Academic Method, Autism Spectrum, Biography, Disability, Interdisciplinary Research, Representation
Commonality of Enemies
Carlism and anarchism were revolutionary social movements that acquired significant popular support during the most intensive period of modernization in Spain (mid 19th to mid 20th centuries). It was noted but not well explored by contemporaries and historians that these enemies were similar in their hostility towards modernization and in their intense idealism. This thesis compares the two movements in order to determine the nature of their commonality and what this suggests about ideological enemies. A range of sources were consulted, including scholarship on modern Spain, biographical information on individuals who converted from Carlism to anarchism and contemporary print media. It was concluded that they were produced by the same destabilizing processes of disentailment and industrialization, which drew the working classes towards proposals that would have otherwise seemed implausibly utopian. The thesis further suggests that they were uniquely idealistic, in that they put moral integrity before the success of their cause. Author Keywords: anarchism, Carlism, enemy other, modernization, Modern Spain, social movements
"TOUGH BUT NECESSARY"? AN ANALYSIS OF NEOLIBERAL AND ANTI-FEMINIST DISCOURSES USED IN THE ELIMINATION OF THE NEW BRUNSWICK ADVISORY COUNCIL ON THE STATUS OF WOMEN
This study demonstrates that the New Brunswick government rationalized the 2011 elimination of the New Brunswick Advisory Council on the Status of Women (NBACSW) by discursively framing it as a duplication of services and as a non-essential service. The study relies on interviews with women who had been involved with the NBACSW, as well as literature about the use of neoliberal and anti-feminist discourses at the national level. I argue that the two rationalizations offered by the New Brunswick government rely on similar neoliberal and anti-feminist discourses to those used at the national level to eliminate women's institutional machinery and thus diminish women's capacities for advocacy and political representation. I argue that this discursive move positioned the province's largest women's advocacy group as an impediment to the common good of the province and as a threat to "Ordinary New Brunswickers," signalling a negative step for women in the province. Author Keywords: Anti-feminist backlash, Canadian Feminism, Canadian Women's Movements, Discourse Analysis, Neoliberalism, New Brunswick
Why do landowners restore wetlands? A case study from east central Ontario
Wetlands were once widespread in southern Ontario, but many have been drained through land use changes. Using a case study of twelve landowners in the Kawartha region, I explored motivations for restoring wetlands. Psychological research suggests that people who are more connected to nature and attached to place are more likely to behave sustainably. Results showed that having land available and receiving funding were necessary preconditions. Connectedness to nature and place attachment were motivations, as were personal benefits and having a supportive social community. Challenges included: the Permit to Take Water, paperwork and bureaucracy, delays and timing, and economic restrictions. Positive outcomes were: increased property value and crop productivity; personal enjoyment of wetlands; and improved wildlife habitat and water quality. Negative outcomes were: `nuisance' wildlife, trespassing, and a lack or excess of water. This is a novel study exploring nature connectedness, place attachment and wetland restoration qualitatively in southern Ontario. Author Keywords: agriculture, connection to nature, motivation, southern Ontario, stewardship, wetland restoration
Habitat use and community structure of grassland birds in southern Ontario agro-ecosystems.
Most grassland bird populations are in decline, so it is becoming increasingly important to understand how they use agricultural field types and form their communities. I performed point counts in cultural meadow, intensive agriculture, and non-intensive agriculture areas in 2011 and 2012. Generalized linear models were used to determine the habitat relationships of six focal species. I found that non-intensive agriculture was used most often and intensive agriculture was often avoided, but there were exceptions which indicate habitat use can be species-specific. I determined in which habitats competition was likely occurring and which species pairs were competing in 2011. In 2012, I experimentally tested these relationships by introducing artificial competitors onto sites. By comparing presence-absence data from 2011 to 2012, I found evidence of habitat-mediated interspecific and conspecific attraction involving Bobolink and Grasshopper Sparrow. This research contributes to the current understanding of grassland bird community ecology and conservation. Author Keywords: agriculture, BACI, community ecology, habitat use, species at risk, species interactions

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Format: 2024/03/28