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Time to adapt: Characterizing adaptive genetic variation of Canada lynx using coding trinucleotide repeats

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Creator (cre): Prentice, Melanie Brooke, Thesis advisor (ths): Wilson, Paul J, Thesis advisor (ths): Bowman, Jeff, Degree committee member (dgc): Murray, Dennis L, Degree granting institution (dgg): Trent University
Abstract:

To better understand species' resilience to climate change and implement solutions, we must conserve environments that maintain standing adaptive genetic variation and the potential generation of new beneficial alleles. Coding trinucleotide repeats (cTNRs) providing high-pace adaptive capabilities via high rates of mutation are ideal targets for mitigating the decline of species at risk by characterizing adaptively significant populations. Ultimately, adaptive genetic information will inform the protection of biological diversity below the species level (i.e., "Evolutionarily Significant Units" or "ESUs"). This dissertation investigates cTNRs within candidate genes to determine their prevalence and influence under selection in North American mammals. First, I evaluated the potential for somatic mosaicism in Canada lynx (Lynx canadensis), and found that tissue-specific mosaicism does not confound cTNR genotyping success in lynx. Second, I assessed a selection of clock gene cTNRs across characterized mammals and found that these repeats are abundant and highly variable in length and purity. I also identified preliminary signatures of selection in 3 clock gene cTNRs in 3 pairs of congeneric North American mammal species, highlighting the importance of cTNRs for understanding the evolution and adaptation of wild populations. I further evaluated the influence of selection on the NR1D1 cTNR within Canada lynx sampled across Canada using environmental correlation, where I estimated the variation in NR1D1 cTNR alleles explained by environmental and spatial variables after removing the effects of neutral population structure. Although most variation was explained by neutral structure, environment and spatial patterns in eastern lynx populations significantly explained some of the variation in NR1D1 alleles. To examine the role of island populations in the generation and distribution of adaptive genetic variation, I used 14 neutral microsatellites and a dinucleotide repeat within a gene linked to mammalian body size, IGF-1, and found that both genetic drift and natural selection influence the observed genetic diversity of insular lynx. Finally, I estimated the divergence dates of peripheral lynx populations and made recommendations towards the conservation of Canada lynx; high levels of genetic differentiation coupled with post-glacial colonization histories and patterns of divergence at cTNR loci suggest at least 4 ESUs for Canada lynx across their range.

Author Keywords: adaptation, Canada lynx, candidate genes, coding trinucleotide repeats, evolution, natural selection

2018

Making home and making welcome: An oral history of the New Canadians Centre and immigration to Peterborough, Ontario from 1979 to 1997

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Creator (cre): Macnab, Maddy, Thesis advisor (ths): Sangster, Joan, Thesis advisor (ths): Chazan, May, Degree committee member (dgc): Lem, Winnie, Degree granting institution (dgg): Trent University
Abstract:

This thesis documents an oral history of the New Canadians Centre, the only immigrant-serving organization in Peterborough, Ontario. This case study builds on scholarship that critically examines immigrant settlement work in Canada. Drawing on interviews and archival research, and employing the analytical concept of home, I investigate how differently-located actors have practiced home and welcome in Peterborough in the context of settlement work. I demonstrate how the New Canadians Centre's work consolidated as well as challenged normative discourses of home that disadvantage racialized new immigrants and privilege white settlers represented as "host." I argue that this false binary between immigrant and host is harmful, inadequate in accounting for the complexities of people's lives, and easily reinforced in settlement work without efforts to challenge it. I conclude that accountability to power in settlement work is crucial to envisioning a more inclusive welcome and a more just home in Peterborough and Canada.

Author Keywords: home, immigrant settlement sector, migration, oral history, Peterborough, welcome

2018

Agriculture as Niche Construction: Eco-Cultural Niche Evolution During the Neolithic (c. 6200 - 4900 BC) of the Struma River Valley

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Creator (cre): Whitford, Brent Robbie, Thesis advisor (ths): Conolly, James, Degree committee member (dgc): Dubreuil, Laure, Degree committee member (dgc): Fitzsimons, Rodney, Degree granting institution (dgg): Trent University
Abstract:

The Neolithic Period (c. 6200 – 4900 BC) in the Struma River Valley led to numerous episodes of cultural diversification. When compared with the neighbouring regions, the ecological characteristics of the Struma River Valley are particularly heterogeneous and the Neolithic populations must have adapted to this distinctive and localized ecological setting. It then becomes reasonable to ask if the evolution of cultural variability in the Struma River Valley was at least partially driven by the ecological setting and differentiation in the evolution of the early agricultural niche. In this thesis, I apply an approach based on niche construction theory and Maxent species distribution modeling in order to characterize the relationship between culture and ecology during each stage of the Neolithic Period and to assess diachronic change. An interpretation of the results demonstrates that the continuous reconstruction of the early agricultural niche allowed for settlement expansion into new eco-cultural niches presenting different natural selection pressures and that cultural change followed. I also found that cultural and historical contingencies played an equally important role on the evolution of populations and that ecological factors alone cannot account for the numerous episodes of cultural diversification that occurred throughout the region.

Author Keywords: Agriculture, Bulgaria, Eco-cultural Niche Modeling, Greece, Neolithic, Niche Construction

2017

The relationship of policy aims and implementation: Ontario coordinated care planning for people with mental health and addictions issues

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Creator (cre): Tallon, Matt, Thesis advisor (ths): Ballantyne, Peri, Degree committee member (dgc): Changfoot, Nadine, Degree granting institution (dgg): Trent University
Abstract:

Background: Ontario's Ministry of Health and Long Term Care (MOHLTC) claims people with mental illnesses/addictions need improved care/overuse emergency departments. MOHLTC expects Coordinated Care Planning (CCP, teams of mental/physical health professionals, social workers and informal caregivers) to improve care and lower emergency department returns/healthcare costs. CCPs are directed by policies, Smith's "problematics," or Deleuze's "expressions," supposedly reflecting "contents"/"everyday worlds."

Research Question: How do Ontario health/allied professionals come together with a person with mental illness/addictions and informal caregiver(s) to address health needs through a CCP?

Method: 1) Analyzed CCP policies; generated questions about creation/implementation. 2) Interviewed eight professionals about interpreting/enacting policies. 3) Connected interview data to policies.

Findings: Opportunities for fragmentation exist in gaining consent; determining eligibility; persons in care, informal caregivers and professionals' participation; person-centeredness; "shame-free" environments; health literacy; records of medications.

Conclusion: CCP participants need to minimize fragmentations which takes time, space, money; creates contradictions in lowering costs/improving care.

Author Keywords: Addiction, Dual Diagnosis, Health Care Policy, Institutional Ethnography, Integrated Health Care, Mental Illness

2017

A wind tunnel and field evaluation of the efficacy of various dust suppressants

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Creator (cre): Preston, Colette Alexia, Thesis advisor (ths): McKenna Neuman, Cheryl, Degree committee member (dgc): Boulton, Wayne, Degree committee member (dgc): Buttle, James, Degree committee member (dgc): Eimers, Catherine, Degree granting institution (dgg): Trent University
Abstract:

A series of experiments was designed to assess the relative efficacy of various dust suppressants to suppress PM10 emissions from nepheline syenite tailings. The experiments were conducted in the Trent University Environmental Wind Tunnel, Peterborough, Ontario, and on the tailings ponds at the Unimin Ltd Nephton mine near Havelock, Ontario. Treated surfaces were subjected to particle-free airflow, abrasion with blown sand particles, particle-free airflow after physical disturbance, and were measured independently using a pin penetrometer. In the particle-free wind tunnel tests, three of the surfaces performed well, and PM10 emissions scaled inversely with crust strength. Light bombardment of each surface by saltating sand grains resulted in PM10 emission rates two orders of magnitude higher. All treated surfaces emitted significantly more PM10 after physical disturbance in both the laboratory and field research. The results suggest that the site conditions, inclusive of the potential for dust advection and resuspension, must be taken into account when considering the use of a commercial dust suppressant.

Author Keywords: dust suppression, field testing, mine tailings, wind tunnel experiment

2018

Discontinuities in stream networks: the effects of tributary size and type on benthic invertebrate communities downstream from confluences

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Creator (cre): Brochu, Melissa, Thesis advisor (ths): Jones, Nicholas E, Thesis advisor (ths): Frost, Paul C, Degree committee member (dgc): Melles, Stephanie J, Degree granting institution (dgg): Trent University
Abstract:

The network composition hypothesis (NCH) suggests that i) large confluence symmetry ratios (drainage area of the tributary relative to the mainstem) and ii) landscape differences (differences in landscape characteristics between the mainstem and tributary drainages) lead to greater ecological changes below confluences. As a test of the NCH, 34 confluences were sampled in southern Ontario to examine the effects of these two factors on benthic invertebrate communities to infer the degree of ecological change at confluences. Given the typology of streams surveyed, there was subtle evidence that benthic invertebrate communities below confluences changed as a function of confluence symmetry ratio and landscape differences. This indicates that abrupt changes in stream networks are not as common as theory may suggest. Further support for the network composition hypothesis may be found by examining a wider range of stream types and examining single-species responses.

Author Keywords: benthic invertebrates, community similarity, landscape characteristics, stream networks, tributary

2018

Assessment of an adult lake sturgeon translocation (Acipenser fulvescens) reintroduction effort in a fragmented river system

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Creator (cre): Boothroyd, Maggie, Thesis advisor (ths): Wilson, Chris C, Thesis advisor (ths): Whillans, Tom, Degree committee member (dgc): Haxton, Tim, Degree granting institution (dgg): Trent University
Abstract:

North American freshwater fishes are declining rapidly due to habitat fragmentation, degradation, and loss. In some cases, translocations can be used to reverse local extirpations by releasing species in suitable habitats that are no longer naturally accessible. Lake sturgeon (Acipenser fulvescens) experienced historical overharvest across their distribution, leading to endangered species listings and subsequent protection and recovery efforts. Despite harvest and habitat protections, many populations do not appear to be recovering, which has been attributed to habitat alteration and fragmentation by dams. In 2002, 51 adult lake sturgeon from the Mattagami River, Ontario, Canada were translocated 340 km upstream to a fragmented 35 km stretch of the river between two hydroelectric generating stations, where sturgeon were considered extirpated. This study assessed the translocation effort using telemetry (movement), demographics and genetic data. Within the first year, a portion of the radio-tagged translocated individuals dispersed out of the release area, and released radio-tagged individuals used different areas than individuals radio-tagged ten years later. Catches of juvenile lake sturgeon have increased over time, with 150 juveniles caught within the duration of this study. The reintroduced population had similar genetic diversity as the source population, with a marked reduction in effective population size (Ne). The results indicate that the reintroduction effort was successful, with evidence of successful spawning and the presence of juvenile lake sturgeon within the reintroduction site. Overall, the results suggest adult translocations may be a useful tool for re-establishing other extirpated lake sturgeon populations.

Author Keywords: conservation, endangered species, lake sturgeon, reintroduction, telemetry, translocation

2018

Intra-seasonal Variation in Black Tern Nest-site Selection and Survival

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Creator (cre): von Zuben, Valerie, Thesis advisor (ths): Nocera, Joseph J, Thesis advisor (ths): Nol, Erica, Degree committee member (dgc): Beresford, David V, Degree granting institution (dgg): Trent University
Abstract:

Resources and risk are in constant flux and an organism's ability to manage change may improve their likelihood of persistence. I examined intra-seasonal variation in nest-site selection and survival of a declining wetland bird, the Black Tern (Chlidonias niger surinamensis). I modelled nest site occupancy and survival of early and late-nesting birds as a function of static and dynamic factors. Early-nesting birds selected nest sites based on the degree and direction of habitat change that occurred over the nesting cycle, while late-nesting birds selected sites based on static conditions near the time of nest-site selection. Nest age had the strongest influence on daily survival rate for both early and late-nesting birds, but the shape of this relationship showed intra-seasonal differences. Additionally, early-season survival improved slightly with increasing vegetation coverage and distance between conspecific nests, while late-season survival increased with clutch size. My results suggest that intra-seasonal variation in nest-site selection and survival is driven by changing habitat conditions and predator behavior.

Author Keywords: Black Tern, Chlidonias niger surinamensis, daily survival rate, intra-seasonal variation, nest-site selection

2018

Using automated radio-telemetry to link food availability, reproductive success, and habitat use of Barn Swallows (Hirundo rustica erythrogaster)

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Creator (cre): Lenske, Ariel, Thesis advisor (ths): Nocera, Joseph J, Degree committee member (dgc): Schaefer, James A, Degree committee member (dgc): Nol, Erica, Degree granting institution (dgg): Trent University
Abstract:

Drivers of North American Barn Swallow population declines are not well understood, but foraging habitat loss is thought to be a contributing factor. Determining patterns of habitat use is challenging for swallows because they move rapidly but are too small to carry GPS tags. We showed that automated radio-telemetry could be used to track the movements of swallows with enough accuracy (median error 250 m) to monitor local habitat use. We then combined information on breeding Barn Swallows habitat use, land cover, aerial insect abundance, and fledging success to test for a link between foraging habitat quality and reproductive success. Foraging activity was concentrated within 600 m of nest sites and varied with land cover; however, responses to land cover were not consistent across birds. Aerial insects were most abundant near wetlands and least abundant near open water and over cropland. Consistent with a link between foraging habitat and reproductive success, nests in barns with more wetland and less open water within 1 km, and with less field area within 2 km occupied by row crops, on average fledged more young swallows.

Author Keywords: aerial insectivores, automated telemetry, habitat use, land cover, movement, nest success

2018

The Impact of Agricultural Land Use on Bobolink Occurrence, Abundance, and Reproductive Success in an Alvar Landscape

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Creator (cre): Pintaric, Alice Lea, Thesis advisor (ths): Nol, Erica, Degree committee member (dgc): Burness, Gary, Degree committee member (dgc): Schaefer, Jim, Degree granting institution (dgg): Trent University
Abstract:

Pastures and hayfields provide surrogate habitat for many declining grassland birds. Understanding agricultural land use dynamics and habitat quality can impact conservation of grassland species. I investigated 1) patterns of land use change in protected and unprotected sites in relationship to Bobolink occurrence in Carden, Ontario, Canada and 2) whether continuous grazing at lowmoderate cattle densities provided suitable breeding habitat, using both real and artificial nests. I replicated the 2001-2005 Ontario Breeding Bird Atlas to evaluate site habitat changes and Bobolink population trends. In continuously grazed pastures and late-cut hayfields, I monitored Bobolink abundance and reproductive success and modeled daily survival rate of nests using habitat management, vegetation structure, and prey availability. Results indicated that Bobolink have declined by -15.3% since 2001 in Carden; losses were explained almost entirely by changes from suitable breeding habitat (e.g. hayfields) to tilled land or by the colonization of shrubs. For pastures, stocking densities of ≤ 1Animal Units/ha did not negatively impact Bobolink. Year and caterpillar biomass, and vegetation height were the strongest predictors of nesting success in pastures and hayfields, respectively. Focus on the preservation of suitable habitat on the breeding grounds and management on small-scale beef farms can contribute to conservation action for this declining species.

Author Keywords: agricultural management, avian ecology, Bobolink, continuous grazing, grassland birds, nest success

2018