Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Population cycles are regular fluctuations in population densities, however, in recent years many cycles have begun to disappear. With Canada lynx this dampening has also been seen with decreasing latitude corresponding to an increase in prey diversity. My study investigates the role of alternate prey on the stability of the lynx-hare cycle by first comparing the functional responses of… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Arctic Char (Salvelinus alpinus (L.)) have been, and remain, an important</p><p>subsistence resource for the Inuvialuit, the Inuit of the western Canadian Arctic. The effects</p><p>of climate variability and change (CVC) in this region have been noticeably increasing over</p><p>the past three decades. There are concerns as to how CVC will affect Arctic… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The potential release of nanoparticles into aquatic environments is raising global concerns. As antimicrobials, silver nanoparticles (AgNPs) are among the most prominent form in use. Despite this, their fate, long-term toxicity, and ecological relevance have yet to be investigated largely under natural settings with seasonality and environmental complexity. To better understand the… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The purpose of this thesis is to enhance forensic entomology applications through identifications and ecological research with samples collected in collaboration with the OPP and RCMP across Canada. For this, we focus on blow flies (Diptera: Calliphoridae) and present data collected from 2011-2013 from different terrestrial habitats to analyze morphology and species composition.… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Polar bears are generally described as solitary, but features of their life cycles and </p><p>habitats regularly necessitate interaction. Effective conspecific assessment, including accurate </p><p>recognition and discrimination, likely confers benefits, especially to females accompanied by </p><p>dependent young. Individuals in the Southern (SH) and… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Early developmental stages of cold-adapted ectotherms such as brook trout </p><p>(Salvelinus fontinalis) are at risk of mortality with increasing water temperatures because </p><p>of their sensitivity to changes in their environment. I studied the mass and routine </p><p>metabolic rate (RMR) of wild-origin brook trout eggs, alevin and young fry reared… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Biological differences between island and mainland conspecifics have been well studied, but few studies have addressed differences in stress physiology. Stressors, such as predation and competition for resources, cause the release of glucocorticoids (GCs). Characteristics of island wildlife, called "island syndrome", are attributed to low levels of predators and competitors. I… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Wild lupine (Lupinus perennis) restoration efforts seek to increase and connect populations, using seeds, to facilitate the recovery of endangered butterflys in Ontario. This study observed plant growth and phytohormone levels of L. albus, L. polyphyllus, and L. perennis through stages of seed development, each with varying strategies in growth and reproductive investment. L. polyphyllus… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Desantis, Lanna Marie, Thesis advisor (ths): Bowman, Jeff, Thesis advisor (ths): Burness, Gary, Degree committee member (dgc): Rafferty, Steven, Degree committee member (dgc): Wilson, Paul, Degree committee member (dgc): Boonstra, Rudy, Degree committee member (dgc): Vijayan, Mathilakath M, Degree granting institution (dgg): Trent University Abstract: <p>Across vertebrate taxa, the hypothalamic-pituitary-adrenal axis (or the stress axis) is highly conserved, and is central to vertebrate survival because it allows appropriate responses to psychological stressors. Habitat shapes successful physiological and ecological strategies, and to appreciate how individual species respond to stressors in their environment, it is essential to have a… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Franckowiak, Ryan Patrick, Thesis advisor (ths): Wilson, Chris C., Thesis advisor (ths): Ridgway, Mark S., Degree committee member (dgc): Dunlop, Erin S., Degree committee member (dgc): Schaefer, James A., Degree granting institution (dgg): Trent University Abstract: <p>Identifying the biotic and abiotic factors that influence individual reproductive fitness under natural conditions is essential for understanding important aspects of a species' evolutionary biology and ecology, population dynamics, and life-history evolution. Using next generation sequencing technology, I developed five microsatellite multiplex reactions suitable for conducting… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Exposure of pre-metamorphic amphibians to neonicotinoid insecticides may be contributing to the global decline in amphibian populations. In this study, anuran embryos and tadpoles of the African clawed frog (Xenopus laevis) and the North American leopard frog (Lithobates pipiens) were used to determine the effects of embryonic exposure to neonicotinoids. In addition, Xenopus was used to… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Mountain ranges are often thought to restrict movement of wildlife, yet previous studies evaluating the role of the Rocky Mountains as a dispersal barrier for Canada lynx (Lynx canadensis) have been contradictory. Our study uses neutral microsatellite loci to evaluate the role of the Rocky Mountains as a barrier to gene flow for lynx. Although lynx exhibited low genetic differentiation,… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Blackfin Cisco (Coregonus nigripinnis), a deepwater cisco species once endemic to the Laurentian Great Lakes, was discovered in Algonquin Provincial Park in four lakes situated within a drainage outflow of glacial Lake Algonquin. Blackfin habitat preference was examined by analyzing which covariates best described their depth distribution using hurdle models in a multi-model approach.… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>I examined Bank Swallow (Riparia riparia) colony persistence and occupancy, in lakeshore, river and man-made aggregate pit habitat. Habitat persistence was highest on the lakeshore and lowest in aggregate pits, likely due to annual removal and relocation of aggregate resources. Bank Swallow colonies in aggregate pit sites were more likely to persist if a colony was larger or if burrows… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Socio-ecological systems are inherently complex and marine mammals are fundamentally challenging to study. In the Arctic, marine mammals occupy a central ecological role, as nutrient cyclers and as a source of food and culture for Indigenous peoples. Inuit have developed a rich knowledge system, which has not been fully actualized in application in most Arctic research. Considering the… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Metal binding to dissolved organic matter (DOM) determines metal speciation and strongly influences potential toxicity. The understanding of this process, however, is challenged by DOM source variation, which is not always considered by most existing metal speciation models. Source determines the molecular structure of DOM, including metal binding functional groups. This study has… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The amitochondrial protozoan, Giardia intestinalis, encodes four members of the cytochrome b5 (CYTB5) family of heme proteins of unknown function. While homology models can predict the likely fold of these proteins, supporting experimental evidence is lacking. The small size of the cytochromes (~16 kDa) makes them attractive targets for structural analysis by Electron Paramagnetic… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The parasitic protist Giardia intestinalis lacks most heme proteins yet encodes a flavohemoglobin (gFlHb) that converts nitric oxide to nitrate and likely protects the cell from nitrosative stress. In this work an antibody raised against gFlHb was used to examine both changes in gFlHb expression levels and intracellular localization in Giardia in response to nitrosative stress. Giardia… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This study focused on detecting 22 target anti-estrogenic and anti-androgenic compounds in surface waters influenced by both discharges of municipal wastewater and agricultural runoff in Canada and Argentina. Polar organic chemical integrative samplers (POCIS) were used to monitor the target compounds in surface waters. The removals of the target compounds in a municipal wastewater… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Chemical cues are used commonly by prey to identify predation risk in aquatic environments. Previous work has indicated that negatively-charged ions of m/z 501 are possibly a kairomone that induces anti-predator responses in tadpoles. This thesis found that this ion species: (i) is produced by injured tadpoles; (ii) exhibits increased spectral intensity with higher tadpole biomass; and (… more