Animal Sciences Commons^™

The Effect Of Dietary Thiaminase On Cardiac Function And Morphology In Lake Trout (Salvelinus Namaycush), Peter Baker

Electronic Thesis and Dissertation Repository

Thiamine deficiency from the consumption of invasive, high-thiaminase prey fishes is considered to be a major barrier for lake trout restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function. I examined the effects of dietary thiaminase on cardiac function and morphology in lake trout, specifically as they relate to thermal tolerance. Two hatchery strains of lake trout (Seneca and Slate) were raised on a control or thiaminase diet for nine months. The thiaminase diet was associated with significant ventricle enlargement, impaired cardiac function, and reduced thermal tolerance; these effects were …

Using Spatial Methods To Analyse Anthropogenic Predation Risk And Movement Ecology Of White-Tailed Deer (Odocoileus Virginianus), Rhiannon D. Kirton

Electronic Thesis and Dissertation Repository

Hunting has been used as a central tool by wildlife managers to maintain populations of game species, however, we still lack a good understanding of exactly how hunting influences deer biology. Technological advances in GPS data over the last two decades now enable us to perform more detailed analysis on the effects of human hunters on wildlife populations. This research explores the spatial ecology of hunters and White-tailed deer in the Cross Timbers ecoregion of Oklahoma. Using new statistical methodologies to analyse simultaneous GPS tracking data on deer and hunters to study their spatial interactions. The results show how new …

Diversity And Drivers Of Oribatid Mites (Acari: Oribatida) In Boreal Peatlands, Carlos Rafael De Araujo Barreto

Electronic Thesis and Dissertation Repository

Boreal peatlands are important ecosystems for carbon cycling, storing 1/3 of the world’s terrestrial carbon in only ~3% of the globe, making them a key component of potential mitigation strategies in response to global climate warming. Experiments have shown that warming can affect plant and microbial communities in ways that potentially shift peatlands from carbon sinks to sources. Soil food webs, including the microarthropod community, are key in carbon cycling but are relatively understudied both in peatlands and under experimental warming. My research capitalized on a large-scale experimental field manipulation of warming in two contrasting peatland sites in Northern Ontario, …

Circannual Patterns Of Adipose Tissue Characteristics In A Hibernator, The Thirteen-Lined Ground Squirrel (Ictidomys Tridecemlineatus), Amanda Maccannell

Electronic Thesis and Dissertation Repository

Obligate hibernators express circannual patterns of body mass and hibernation, which persist under constant laboratory conditions. I hypothesized that in the 13-lined ground squirrel (Ictidomys tridecemlineatus) thermogenic brown adipose tissue (BAT) and lipid storing white adipose tissue (WAT) volume would follow a circannual pattern. I housed animals at either 25°C (thermoneutral) or 5°C with 12h L:12h D photoperiods for an entire year. I determined volume and water-fat ratio of WAT and BAT using magnetic resonance imaging (MRI). BAT volume follows a circannual pattern in both conditions, increasing prior to winter, decreasing in late winter with no change in …

Resource Selection, Survival, And Departure Of Adult Female Mallards From The Lake St. Clair Region During Autumn And Winter, Matthew Palumbo

Electronic Thesis and Dissertation Repository

During autumn and winter, mallards (Anas platyrhynchos) maximize fitness through their spatiotemporal distribution to avoid mortality risks while balancing trade-offs to access foods to undergo migration and maintain homeostasis. Thousands of mallards use Lake St. Clair as it is an important, but threatened, migratory staging area in the Great Lakes. My goal was to understand how mallards were selecting resources in the region and potential relationships of selection strategies. My objectives were to estimate resource selection of adult female mallards, in relation to perceived risk of hunting mortality, and determine if selection strategies were related to survival and …

Regulation Of Liver Mitochondrial Metabolism During Hibernation By Post-Translational Modification, Katherine E. Mathers

Electronic Thesis and Dissertation Repository

Hibernation, characterized by a seasonal reduction in metabolism and body temperature, allows animals to conserve energy when environmental conditions (e.g. temperature, food availability) are unfavourable. During hibernation, small mammals such as the 13-lined ground squirrel (Ictidomys tridecemlineatus) cycle between two distinct metabolic states: torpor, where metabolic rate is suppressed by >95% and body temperature falls to ~5 °C, and interbout euthermia (IBE), where metabolic rate and body temperature rapidly increase and are maintained at euthermic levels several hours. Suppression of metabolism during entrance into torpor is paralleled by rapid suppression of liver mitochondrial metabolism. In my thesis, I …

Autumn Foraging And Staging Ecology Of Eastern Population Sandhill Cranes (Antigone Canadensis Tabida), Everett E. Hanna

Electronic Thesis and Dissertation Repository

Spatial and temporal variation in the density and distribution of waste agricultural grain (grain herein) during staging can affect the carrying capacity of habitats that support avian populations. Such variation in food resources can also have proximate effects on behavioural ecology (e.g., influence optimal behaviour). The Eastern Population of Greater Sandhill Cranes (Antigone canadensis tabida; EP herein) likely began to recolonize Ontario and its historic range starting in the early 1900s and now relies on agricultural grain during migration. Accordingly, ecologists possess little knowledge of how EP crane behavioural ecology may be affected by grain. Thus, my study …

Evolutionary Genetic Aspects Of Host Association In Generalist Ectoparasites, Benoit Talbot

Electronic Thesis and Dissertation Repository

Despite the use of the host for dispersal by most parasite species, the extremely loose relationship typical between highly mobile hosts and generalist ectoparasites may lead to very different gene flow patterns between the two, leading in turn to different spatial genetic structure, and potentially different demographic history. I examined how similar gene flow patterns are between Cimex adjunctus, a generalist ectoparasite of bats present throughout North America, and two of its key bat hosts. I first analyzed the continent-scale genetic structure and demographic history of C. adjunctus and compared it to that of two of its hosts, the …

Fear Of Predators Compromises Parental Care And Juvenile Survival In A Songbird, Philip Blair Dudeck

Electronic Thesis and Dissertation Repository

Predators kill, but the risk of being killed is also a powerful force affecting survival because scared prey eat less, thereby increasing the likelihood of starvation. Young of most animals are extremely vulnerable to predators and may alter their behaviour to limit detection. I investigated the previously unexplored effects that predation risk has on the behaviour of newly fledged offspring and their parents, and the impact this has on offspring survival. I manipulated predation risk using sound and found that parent song sparrows reduced their feedings, providing 60% less food overall. Critically, not only did this parental response estimate survival …

Fish Out Of Salt Water: Smoltification In Subyearling Chinook Salmon From The Laurentian Great Lakes, Steve Sharron

Electronic Thesis and Dissertation Repository

The timing of smoltification in juvenile anadromous salmonids is important to ensure individuals match their preparedness with their migration timing and the optimal conditions in the environment. I performed the first study of smoltification in adfluvial juvenile Chinook salmon naturalized in the Laurentian Great Lakes. In a hatchery study, I found that juveniles from one of these populations have similar patterns of smoltification timing to individuals from anadromous populations. Their Na⁺/K⁺ ATPase activity, a common indicator or smolt status, peaked at 7.7 μmoles ADP/mg protein/hour on July 1 in freshwater. During the peak period, individual body size …

The Role Of Islands In The Migration Of Bats Across Lake Erie And Lake Ontario: Lasiurus Borealis, Lasiurus Cinereus And Perimyotis Subflavus, Toby J. Thorne

Electronic Thesis and Dissertation Repository

Large bodies of water, such as the Great Lakes in North America, are potential barriers to migrating bats. Islands may be used as stopover sites by bats crossing the Great Lakes as stopover sites, or included in crossing routes to reduce the distance flown over open water. I predicted that stopover use by migrating bats would result in higher activity on Great Lakes islands during late-season migration than at mainland sites. I monitored acoustic activity at 11 sites across four locations in Ontario: Amherst and Pelee islands, Kingston and Pinery Provincial Park during the summer (June and July), and during …

Low Temperature Tolerance Of Adult Drosophila Suzukii (Diptera: Drosophilidae), Ruth Jakobs

Electronic Thesis and Dissertation Repository

The crop pest Drosophila suzukii, native to Southeast Asia, has been found in Ontario since 2010. This raises concern with respect to it establishing permanent populations, however, little is known about its cold tolerance. I investigated the low-temperature tolerance, including phenotypic plasticity, of D. suzukii. While acclimation increased cold tolerance, there was no evidence of short-term cold-hardening. Chill coma occurs at -1.2 °C, which will limit winter activity. Cold shock decreased the reproductive output of females, but this negative effect may be mitigated by re-mating. Drosophila suzukii is chill-susceptible and 80 % of the flies die after exposure …

Environmental Factors Influencing Spring Migration Chronology Of Lesser Scaup (Aythya Affinis), Taylor A. Finger

Electronic Thesis and Dissertation Repository

Weather likely affects the timing and rate of migration by waterfowl to their breeding grounds. I hypothesized that timing of migration by lesser scaup during spring is affected by annual variation in temperature, precipitation and ice cover. I used satellite telemetry data, waterfowl survey data and corresponding weather data to evaluate competing models that explained variation in timing and rate of migration by lesser scaup. Timing of spring migration occurred earlier and faster when lesser scaup encountered warmer temperatures and greater precipitation, both of which are known to influence thermoregulation and habitat availability for waterfowl. Migration chronology of lesser scaup …

Developmental Plasticity Of Muscle Cellularity And Swim Performance Of Juvenile Chinook Salmon In Response To Temperature, Dan Dohyung Lim

Electronic Thesis and Dissertation Repository

I investigated the influence of incubation temperature on muscle development and swim performance in juvenile Chinook salmon (Oncorhynchus tshawytscha). In 2011 and 2012, embryos were incubated at different combinations of temperature (7, 9, 15 °C), before and after the onset of free swimming. High-intensity fixed velocity swim tests were performed to assess anaerobic capacity of juveniles. In 2012, these tests were done at a standardized body size (~40 mm). The mean (least-squares) logged times to fatigue of the 15 °C-incubated fish was higher (0.623 ± 0.049 SE) than the 7 °C-incubated fish (0.435 ± 0.048 SE) even after …

The Effects Of Extrinsic And Intrinsic Factors On The Reproductive Biology Of Male Western Bean Cutworm Moths, Striacosta Albicosta (Smith), Jasmine Farhan

Electronic Thesis and Dissertation Repository

Pheromones are important in the mating systems of nocturnal moths as they are relied on to find and/or assess mates. Extrinsic and intrinsic factors have been shown to influence female emission of and male response to pheromones. My thesis focuses on the reproductive biology of males of the western bean cutworm, Striacosta albicosta, a pest of beans and corn that has recently began expanding its range eastwardly. I conducted a field-based experiment to determine the effects of extrinsic factors on pheromone trap catches. I also conducted laboratory based mating experiments to determine the effect of male age on acceptance …

Interactions Among Biotic And Abiotic Controls Of Carbon Dynamics In A Global Change Field Experiment, Eric R D Moise

Electronic Thesis and Dissertation Repository

Climate warming and increased atmospheric nitrogen deposition may substantially influence biosphere C cycling over the next century by altering ecosystem processes such as productivity and decomposition. Field studies are commonly used to explore plant responses to global change, although the underlying mechanisms can be difficult to isolate owing to the lack of control of factors such as plant-animal interactions. Ultimately, indirect effects via herbivore and detritivore responses may feedback to influence plant responses to the experimental treatments. The goal of this thesis was to explore interactions among biotic and abiotic drivers of carbon dynamics within the context of experimental warming …

Assessing And Analyzing Bat Activity With Acoustic Monitoring: Challenges And Interpretations, Amanda M. Adams

Electronic Thesis and Dissertation Repository

Acoustic monitoring is a powerful technique for learning about the ecology of bats, but understanding sources of variation in the data collected is important for unbiased interpretation. The objectives of this dissertation were to investigate sources of variation in acoustic monitoring and make recommendations for acoustic survey design and analysis. I addressed this goal in three ways: i) variation resulting from differences in bat detectors, ii) methods for objective identification of peak activity, and iii) the use of stationary transects to address within-site spatial variation.

First, I compared variation of detection of echolocation calls among commonly available bat detectors and …

Environmental Physiology Of Flight In Migratory Birds, Alexander R. Gerson

Electronic Thesis and Dissertation Repository

Migratory birds complete amazing journeys between their breeding and wintering grounds. Each journey comprises a series of flights that last hours to days, followed by stopovers where fuel stores are replenished. Despite the long flights undertaken by migratory birds, where respiratory water losses are high for extended periods of time, birds are not dehydrated after flight. My studies demonstrate that birds maintain hydration by modulating rates of endogenous water production in response to rates of water loss. In resting, water restricted house sparrows (Passer domesticus) I used quantitative magnetic resonance body composition analysis (QMR) and hygrometry to demonstrate that stressed …

Stable Isotope Analyses Of Bat Fur: Applications For Investigating North American Bat Migration, Erin E. Fraser

Electronic Thesis and Dissertation Repository

Many aspects of North American bat migration are not well documented. Stable isotope analyses of animal tissues can elucidate migratory origin, but this technique has not been widely applied to bats. This dissertation i) uses fur stable isotope analyses to investigate North American bat migration and ii) highlights some of the strengths and weaknesses of this analytical technique when applied to bat systems. I conducted stable hydrogen, carbon, and nitrogen isotope analyses on fur from five bat species.

I documented δD_fur heterogeneity in summer resident populations of Myotis lucifugus, Lasiurus borealis, Lasiurus cinereus, and Lasionycteris noctivagans. Stable …

Mitochondrial Metabolic Suppression And Reactive Oxygen Species Production During Hypometabolism In Mammals, Jason Cl Brown

Electronic Thesis and Dissertation Repository

During hibernation, daily torpor, and fasting, mammals reduce metabolic rate (MR) up to 99%, 95%, and 30%, respectively, compared to resting levels. Mitochondrial metabolic suppression likely contributes to this MR reduction, and the first objective of this study was to determine the relative contributions of active, regulated inhibition and passive thermal effects as body temperature (T_b) falls, to mitochondrial metabolic suppression, and to examine the mechanisms involved using top-down elasticity analysis and novel statistical approach. The second objective of this study was to determine how mitochondrial metabolic suppression affects mitochondrial reactive oxygen species (ROS) production, a topic which …