Other Ecology and Evolutionary Biology Commons^™

Freezing Tolerance Of Herbaceous Legumes Within Southwestern Ontario: Evidence Of Disproportionate Freezing Sensitivity, Samuel L. Rycroft

Electronic Thesis and Dissertation Repository

Legumes (Fabaceae) represent a diverse and ecologically significant plant taxon; most described legumes form mutualisms with diazotrophic rhizobia, potentially fixing substantial quantities of nitrogen within habitats where they are well-established. Stressors causing lethal or sub-lethal impacts in legumes or rhizobial symbionts may therefore impact the nitrogen dynamics of such habitats. In recent decades, variability of winter temperatures, precipitation, and soil freeze-thaw cycling has increased in temperate regions. Without adequate snow cover to insulate roots and shoot bases, herbaceous plants will likely be exposed to more frequent or severe freezing. In southwestern Ontario, a pattern of disproportionate freezing sensitivity relative to …

From Micro To Macro: Examining Potential Microbiome Mediated Influences On Human Growth And Health Outcomes Through Breastfeeding And Antibiotic Exposures, Nicole K. Phillips

Electronic Thesis and Dissertation Repository

Human microbiome research has rapidly developed over the past two decades yet absent from most research is the composition and dynamics of microbiomes within human populations. Given the limitations in longitudinal studies which requires decades of repeated microbe taxonomic testing of a population sample, an alternative option is to examine microbiomes and their influences via proxies using pre-existing health datasets. This research demonstrates preliminary associations between presumed disrupted and supportive microbiomes dynamics proxied by antibiotic and breastmilk exposure respectively. Using health record data across the life span from approximately 500,000 U.K. participants, this research demonstrates variable altered growth and health …

Connexin 43 Contributes To Phenotypic Variability Of The Mouse Skull, Elizabeth Jewlal

Electronic Thesis and Dissertation Repository

The purpose of this study was to determine whether connexin 43 (Cx43) contributes to craniofacial phenotypic variability. Skull shape and variation were compared within and among two heterozygous mutant mouse models (G60S/+ and I130T/+) that exhibit different levels of Cx43 channel function when compared to their wildtype counterparts (~80% and ~50% reduction in function, respectively). Results indicated mutants have significant differences in skull shape compared to wildtype littermates. Similar patterns of shape difference were found in both mutants. Increased skull shape variation and a disruption in the covariation of skull structures were observed in G60S/+ mutants only. These results show …

Effects Of Experimental Malaria Infection On Migration Of Yellow-Rumped Warblers (Setophaga Coronata), Rebecca J. Howe

Electronic Thesis and Dissertation Repository

The potential of migratory animals to spread infectious diseases depends on how infection affects movement. If infection delays or slows the speed of travel, transmission to uninfected individuals may be reduced. Whether and how malaria (Plasmodium spp.) affects bird migration has received little experimental research. I captured 40 actively-migrating Yellow-rumped Warblers (Setophaga coronata) at a migration stopover site and held them in captivity. I inoculated 25 with P. cathemerium while 15 received sham inoculations. After 12 days the birds were released. Six P. cathemerium-inoculated birds (24%) developed P. cathemerium infections after inoculation. I radio-tagged all birds, …

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, …

Spatial And Temporal Variation Of Nutrients In The Great Lakes-St. Lawrence Basin: Implications For Primary Production In Stream Ecosystems, Nolan Pearce

Electronic Thesis and Dissertation Repository

Growing human populations and associated land use activities has increased the amount of nutrients delivered to surface waters. Eutrophication from the over-enrichment of nitrogen and phosphorus has degraded ecosystem conditions in streams, lakes, and coastal areas worldwide. Thus, the management of anthropogenic nutrient loading is a global concern. This thesis employed a combination of field and experimental research to provide watershed managers with information on the spatial and temporal patterns in stream nutrient enrichment, and the associated ecological effects of anthropogenic nutrient loading in the Great Lakes-St. Lawrence basin. Four studies were completed to address this research goal. First, I …

Niche Segregation Among Three Sympatric Species Of Swallows In Southern Ontario, Kaelyn H. Bumelis

Electronic Thesis and Dissertation Repository

Barn Swallows (Hirundo rustica), Cliff Swallows (Petrochelidon pyrrhonota) and Tree Swallows (Tachycineta bicolor) breed sympatrically in southern Ontario but it is unclear how these species differ ecologically, and their coexistence implies niche segregation. I investigated potential interspecific differences in nestling diet and post-fledging movements. Using DNA barcoding of nestling feces and stable isotope analysis (δ¹³C, δ¹⁵N, δ²H) of nestling feathers, I found evidence of differences in dietary sources of provisioned young. Barn Swallows showed evidence of provisioning more terrestrial-based prey, Cliff Swallows provisioned an intermediate diet, and Tree …

The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a collective prediction among ecologists that climate change will enhance phytoplankton biomass in temperate lakes. Yet there is noteworthy variation in the structure and regulating functions of lakes to make this statement challengeable and, perhaps, inaccurate. To generate a common understanding on the trophic transition of lakes, I examined the interactive effects of climate change and landscape properties on phytoplankton biomass in 12,644 lakes located in relatively intact forested landscapes. Chlorophyll-a (Chl-a) concentration was used as a proxy for phytoplankton biomass. Chl-a concentration was obtained via analyzing Landsat satellite imagery data over a 28-year period (1984-2011) and using …

Contrasting Non-Breeding Ecology Of Swainson’S Thrush (Catharus Ustulatus) In Andean Forest And Shade-Grown Coffee Plantations, Sean Mcelaney

Electronic Thesis and Dissertation Repository

Shade-grown coffee plantations provide Neotropical migratory birds an alternative to primary growth forest which is disappearing throughout their non-breeding range. However, it remains unclear whether plantations can provide enough structure to maintain viable non-breeding populations of many species. I studied Swainson’s Thrush (Catharus ustulatus) in the Colombian Andes in a mixture of montane forest and shade-grown coffee plantation. In comparing the two habitats I looked at factors indicative of habitat quality, such as age/sex hierarchies, area of concentrated use, density, diet, and migration timing. My research aimed to determine whether Neotropical migrants benefit from this agroecosystem, and to …

Landscape-Level Effects Of Agricultural Intensification On The Condition And Diet Of Nestling Barn Swallows (Hirundo Rustica), Jackson W. Kusack

Electronic Thesis and Dissertation Repository

Farmland bird populations have experienced declines with increasing agricultural intensification for which the leading hypothesis is a reduction of prey insects. This may be especially relevant for aerial insectivores whose primary diet is aerial insects. For this thesis, I examined nestling body condition and used stable isotopes (δ¹³C, δ¹⁵N) and fecal DNA barcoding to determine the diet of a farmland breeding aerial insectivore, the Barn Swallow (Hirundo rustica), within an agro-ecosystem in Southern Ontario, Canada. Nestling body condition was positively affected by agricultural intensification, but all benefits were lost by the pre-fledging stage and …

Spatial And Temporal Patterns Of Neutral And Adaptive Genetic Variation In The Alpine Butterfly, Parnassius Smintheus, Maryam Jangjoo

Electronic Thesis and Dissertation Repository

Understanding how much genetic diversity exists in populations, and the processes that maintain that diversity, has been a central focus of population genetics. The evolutionary processes that determine patterns of genetic diversity depend on underlying ecological processes such as dispersal and changes in population size. In this thesis, I examine the influence of dispersal and population dynamics on neutral and adaptive genetic variation in a naturally occurring network of populations of the alpine butterfly, Parnassius smintheus.

My first objective was to determine the combined consequences of demographic bottlenecks and dispersal on neutral genetic variation within and among populations. Using …

Differential Spring Migration In The White-Throated Sparrow (Zonotrichia Albicollis), Andrew T. Beauchamp

Electronic Thesis and Dissertation Repository

Differential migration timing between distinct classes of individuals is commonly observed in songbirds, however, the underlying behavioural mechanisms of differential timing are still uncertain for most species. My research applied a suite of advanced techniques to examine differential migration timing (by sex and morph) and its underlying behavioural mechanisms (refuelling rate, stopover duration, and wintering latitude) in spring migrating White-throated Sparrows (Zonotrichia albicollis) at a key stopover site. Protandry was the only form of differential migration timing observed, with males arriving at stopover on average 11 days earlier than females. Males and females had similar refuelling rate, stopover …

On Honey Bee Colony Dynamics And Disease Transmission, Matthew I. Betti

Electronic Thesis and Dissertation Repository

The work herein falls under the umbrella of mathematical modeling of disease transmission. The majority of this document focuses on the extent to which infection undermines the strength of a honey bee colony. These studies extend from simple mass-action ordinary differential equations models, to continuous age-structured partial differential equation models and finally a detailed agent-based model which accounts for vector transmission of infection between bees as well as a host of other influences and stressors on honey bee colony dynamics. These models offer a series of predictions relevant to the fate of honey bee colonies in the presence of disease …

The Effects Of Sex, Energy, And Environmental Conditions On The Movement Ecology Of Migratory Bats, Kristin A. Jonasson

Electronic Thesis and Dissertation Repository

Lack of knowledge about the behaviour of migratory species during the migratory period is a major barrier to conservation efforts. In this thesis I focus primarily on differences between the sexes of the bat Lasionycteris noctivagans, during spring migration. Females are pregnant during spring migration and this overlap between migration and reproduction may affect the time and energy management of females as compared to males. In Chapter 2 I examine spring migration phenology of bats at a stopover site. Females arrived earlier than males, likely to give their pups a long growing season. Fat stores appeared to reflect a …

Mhc Class Iiβ Diversity As A Correlate Of Neutral-Locus Similarity And Diversity, And A Predictor Of Overwinter Return, In Song Sparrows (Melospiza Melodia), Matthew J. Watson

Electronic Thesis and Dissertation Repository

Abstract

The major histocompatibility complex (MHC) is a family of genes involved with recognizing pathogens and mounting an immune response. Parasite-mediated selection often favours heterozygosity at MHC because MHC-diverse individuals recognize a wider range of pathogens. Because migratory birds encounter many pathogens, I hypothesized that MHC diversity predicts overwinter and juvenile survivorship in song sparrows (Melospiza melodia). I found no correlation between MHC diversity and neutral-locus (microsatellite) heterozygosity, suggesting that measures of neutral and adaptive genetic diversity provide complementary rather than redundant information. However, pairwise similarity at MHC predicted pairwise similarity at microsatellite loci. In contrast to my hypothesis, MHC …

A Test Of The Effects Of Androgens On Immunity: No Relationship Between 11-Keto Testosterone And Immune Performance In Bluegill Sunfish (Lepomis Macrochirus), John W. Loggie

Electronic Thesis and Dissertation Repository

The posited immunosuppressive effects of androgens are a key component of the immunocompetence handicap hypothesis (ICHH). My thesis uses bluegill sunfish (Lepomis macrochirus) to test two predictions arising from this hypothesis: (1) natural concentrations of the androgen 11-keto testosterone (11-KT) will be negatively related with immunity, and (2) an immunochallenge will lower 11-KT concentration. I found no evidence for a relationship between natural 11-KT concentration and measures of immunity (leukocyte counts, respiratory burst, cytokine gene expression), and an immunochallenge with Vibrio vaccine did not affect 11-KT concentration. I performed a meta-analysis of immunochallenge studies to help interpret my …

First Major Appearance Of Brachiopod-Dominated Benthic Shelly Communities In The Reef Ecosystem During The Early Silurian, Cale A.C. Gushulak

Electronic Thesis and Dissertation Repository

The early Silurian reefs of the Attawapiskat Formation in the Hudson Bay Basin preserved the oldest record of major invasion of the coral-stromatoporoid skeletal reefs by brachiopods and other marine shelly benthos, providing an excellent opportunity for studying the early evolution, functional morphology, and community organization of the rich and diverse reef-dwelling brachiopods. Biometric and multivariate analysis demonstrate that the reef-dwelling Pentameroides septentrionalis evolved from the level-bottom-dwelling Pentameroides subrectus to develop a larger and more globular shell. The reef-dwelling brachiopods in the paleoequatorial Hudson Bay Basin were more diverse than contemporaneous higher latitude reef-dwelling brachiopod faunas, with ten distinct …

Population Genetic Structure And Parasite Communities In A Nomadic Songbird, The Red Crossbill (Loxia Curvirostra), Erica L. Lovett

Electronic Thesis and Dissertation Repository

Although much speciation occurs in allopatry, populations with overlapping geographic ranges may also experience reduced gene flow due to ecological differences. Parasites are an important feature of the biotic environment, and place important selective pressures on their hosts, potentially reducing gene flow among geographically separated host populations. However, virtually nothing is known about host-parasite interactions in systems where hosts have nomadic distributions, and where ecologically distinct populations exist in sympatry. I examined population genetic structuring and characterized bloodborne parasite communities across four ecologically distinct, but partially sympatric, “vocal types” of nomadic red crossbills (Loxia curvirostra) sampled at multiple …

Weather And Photoperiod Indices Of Autumn And Winter Dabbling Duck Abundance In The Mississippi And Atlantic Flyways Of North America, Lena M. Van Den Elsen

Electronic Thesis and Dissertation Repository

Climate change may influence autumn and winter distributions of dabbling ducks throughout the Atlantic and Mississippi Flyways of North America. To determine how weather and photoperiod influenced autumn-winter abundances of dabbling ducks at staging areas in eastern North America, I modeled weather and photoperiod variables with rate of change in relative abundance of various dabbling duck species over space and time. Latitude was incorporated into models to determine if changes in duck abundance in relation to weather severity were influenced by locale. Changes in abundance were best described by weather models incorporating temperature and snowfall variables for all species except …

Natural Variation In Malarial Infection And Immune Investment In A Migratory Songbird, And The Effects Of Infection On Flight Performance, Laura Rooney

Electronic Thesis and Dissertation Repository

Endurance flight and immune defense are energetically costly activities for birds, and there may be a trade-off between migration and immune investment. Avian blood parasites consume host resources, which may decrease a bird’s resource pool so that endurance flight and immune defense may not be possible simultaneously. I developed a molecular method to detect and quantify blood parasite infection in migrating yellow-rumped warblers (Setophaga coronata), and measured immune activity. I assessed the impact of infection on endurance flight performance and refueling in captive birds. Infection status was not related to age or sex, or timing of migration, and …

Movement, Habitat Selection, And Survival Of Female Wood Ducks (Aix Sponsa) And Ducklings At Long Point, Ontario., Matthew E. Dyson

Electronic Thesis and Dissertation Repository

Nest box programs provide additional nesting opportunities for wood ducks throughout their breeding range. The purpose of my research was to understand habitat use and survival of wood ducks produced from nest boxes during the brood-rearing period. I used radio-telemetry to monitor female wood ducks and ducklings to 30 days post-hatch. Females showed the greatest selection for swamp, scrub-shrub, and emergent marsh habitats, and used emergent marsh most. Female survival was high (0.90, 95% CI = 0.81 – 1.0). Conversely, brood survival (0.47, 95% CI = 0.33 - 0.69) and duckling survival (0.18, 95% CI = 0.14 – 0.22) were …

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 …

A Comparison Of Community Composition Analyses For The Assessment Of Responses To Wood-Ash Soil Amendment By Free-Living Nematodes, Paul B.L. George

Electronic Thesis and Dissertation Repository

Land-use changes can have far-reaching consequences for resident communities and ecosystem functioning. Developing appropriate assessment methods to observe and quantify this change is an important application of community ecology. Here I compare four methods of community assessment for free-living soil nematodes under forest harvesting disturbance and wood ash application. Neither morphological assessment (richness, abundance, diversity) nor molecular assessment (morpho-richness using T-RFLP) was responsive to experimental treatments. Trait-based approaches (Maturity Index (MI) and Body Size Spectra (BSS)) were more sensitive to forest harvest and wood-ash amendment treatments. The efficacy of these methods was also qualitatively compared. Of all methods, the BSS …

Application Of Otolith Increment Analysis To The Study Of Maturation Timing In Female Kokanee Salmon, Yelin Xu

Electronic Thesis and Dissertation Repository

I investigated the influence of growth history on the expression of female reproductive tactics in kokanee salmon (Oncorhynchus nerka) from Meadow Creek Spawning Channel, British Columbia, Canada. Female kokanee either arrive at the spawning area with red nuptial coloration, or less commonly, sexually immature with silver coloration. Silver- and red-arriving females may reflect different reproductive strategies in the population. I used otolith increment measurements to determine fish growth. In contrast to earlier studies, silver- and red-arriving females in 2013 did not differ in age at maturity (mostly were age 3+) or size at maturity (length from eye to …

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 …

The Role Of Morphology In Diet And Flower Visitation By Five Species Of Cuban Flower-Visiting Bats, Lindsey Clairmont

Electronic Thesis and Dissertation Repository

Pollinator and flower morphology are important factors in structuring the plant-pollinator relationship. A pollinator’s morphology may influence aspects of its diet. Flower-visiting bats are an important pollinator group but very little is known about what influences their interactions with food plants. I examined the role of morphology in the partitioning of food resources for five species of flower-visiting Cuban bats. I analyzed cranial traits and body size to examine differences among species and to determine the degree of morphological specialization for flower-feeding for each species. I also collected dietary data from guano and used acoustic monitoring to assess bat activity …

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 …

Physiological Ecology Of Bat Migration, Liam P. Mcguire

Electronic Thesis and Dissertation Repository

Migration is perhaps the most poorly understood aspect of bat biology and the underlying physiological basis is virtually unstudied. Although distantly related, bats and birds are both endothermic flying vertebrates and bird migration physiology has been studied for decades. Therefore, I used migratory birds as a model system to make predictions regarding the physiological ecology of bat migration.

First, I compared brain size of migratory and sedentary bat species. Migratory species have smaller brains which suggests the costs of carrying and maintaining a large brain are incompatible with the demands of migration. Next, I studied silver-haired bats (Lasionycteris noctivagans …