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Supervisor: Dr. Brian Branfireun

Northern fen peatlands provide conditions favourable for sulphate reducing bacteria, largely responsible for producing methylmercury, an aquatic pollutant. Observations from a moss-dominated poor fen and sedge-dominated intermediate fen were used to compare spatial and temporal patterns of methylmercury production to assess if contrasting plant communities and nutrients control production. First, comparisons of methylmercury and porewater solutes were measured across two northern Ontario fens. Greater sulphate availability and lower pH in the poor fen resulted in greater methylmercury production. Second, riparian margins in the intermediate fen were evaluate to see if groundwater nutrient supply controlled methylmercury production and transport. Water table fluctuations rather than groundwater supply controlled sulphate availability and methylmercury production. The proximity of riparian margins to stream waters facilitated methylmercury transport to surface waters.

Supervisors: Dr. Ian Scott and Dr. Jeremy N. McNeil

New pest management strategies are required to counter the rise of insecticide-resistance in populations of greenhouse pest insects, for example Trichoplusia ni (Hübner), the cabbage looper moth. One alternative is to use trap crops - planting attractive, disposable plants within the main crop arrangement to draw pests away from the crop of interest. Transgenic Solanum lycopersicum (L) tomato lines were modified to over-express the gene that regulates carotenoid cleavage dioxygenase 1 (LeCCD1) enzymes resulting in altered production of tomato volatiles. The objectives of this study were to assess the attraction of cabbage looper moths to volatiles emitted by transgenic tomato lines relative to wild-type, as well as to determine if the response was modified post-oviposition for the purpose designing a novel trap crop.

Supervisor: Dr. Bryan Neff

The major histocompatibility (MHC) genes encode cell-surface proteins that are responsible for presenting antigen peptides to immune cells. Aside from its vital immune function, the highly variable MHC genes have also been linked to mate choice in multiple species. One hypothesis is that females of some species choose their mates based on dissimilarity at the MHC in order to produce heterozygous offspring with improved immunocompetence. I use bluegill (Lepomis macrochirus) as a study species for MHC-based mate choice. The MHC regions of bluegill mating pairs caught in the act of spawning are being investigated using next gen sequencing techniques.

Supervisors: Dr. Keith A. Hobson and Dr. Jeremy N. McNeil

The true armyworm (Pseudaletia unipuncta), a seasonal migrant, does not overwinter in Canada and I undertook experiments to determine if continental spatial hydrologic scales for deuterium (δ2H) in precipitation could help determine the natal origin of immigrants. Initially I established the relationship between water and wing chitin δ2H by rearing larvae on vegetation treated with different concentrations of deuterated water. I then analyzed the wings of 2016 field-collected moths captured during the three flight periods, testing the hypothesis that spring specimens (immigrants) would have a significantly different δ2H profile than summer (residents) and fall (emigrants) ones. The results indicate that spring moths originate from further south, and the preliminary inter year data suggest that 2008 and 2016 immigrants have similar geographic origins.

Supervisor: Dr. Beth MacDougall-Shackleton

Genes of the major histocompatibility complex (MHC) play a fundamental role in vertebrate immunity. Because selection at MHC often favors particular alleles and allelic combinations, assessing MHC profiles of potential mates should be advantageous. Additonally, in songbirds, candidate signals of MHC remain largely unexplored but may include odor cues from feather preen oil or the content of geographically variable song. Here, I present results on whether specific combinations of MHC alleles confer protection against avian malaria, using song sparrows (Melospiza melodia) as a model species. I will also discuss whether chemical composition of preen oil and song repertoire content reflect song sparrow MHC genotypes.

Supervisors: Dr. Yolanda Morbey and Dr. Christopher Guglielmo

The sex-specific mechanisms underlying protandry, the earlier arrival of males than females to breeding sites, are unknown for most species. Nocturnally migrating birds in cages will show periods of locomotor activity at night during migration periods (migratory restlessness), with the onset reflecting departure and intensity reflecting the migratory distance flown in wild conspecifics. Here, we tested the hypothesis that male black-throated blue warblers have earlier onset of spring migratory restlessness compared to females by using Noldus video analysis software to quantify nocturnal behaviour of birds kept in captivity. No sex-differences were found in the onset of migratory restlessness but males had higher intensity, represented as cumulative activity per night. This suggests that distance flown may be an important driver of protandry in this species.

Supervisor: Dr. Hugh Henry

Oak populations in eastern North America are in steep decline and are being replaced by maples and walnuts. The mechanisms blocking oak recruitment in forests are well understood and include fire suppression, herbivore overpopulation, disease, and altered relationships with soil microorganisms. In contrast, the mechanisms blocking oak recruitment in old field ecosystems are poorly understood. In this study, we manipulate grass cover in old field settings to compare the effects of native grasses versus naturalized European grasses on oak recruitment. Preliminary results show that native oaks are very sensitive to the presence of Festuca rubra while European oaks are not. This European grass produces meta-Tyrosine, a potent allelochemical which European oaks may be tolerant of. The results are interpreted in the context of coevolution.

Supervisor: Dr. Bryan Neff

One potential obstacle to the reintroduction of Atlantic salmon in Lake Ontario is invasive prey fishes. These fishes contain high concentrations of the enzyme thiaminase, which breaks down the essential vitamin thiamine (B1). We compared the effect of dietary thiaminase on reproductive traits in three Atlantic salmon populations (LaHave, Lac Saint-Jean, Sebago), which have previously been used in reintroduction efforts. We hypothesized that a high-thiaminase diet would affect reproductive traits and these effects would differ among the three populations. To test our hypotheses, we performed experimental crosses with our low- and high-thiaminase treatment individuals within populations and measured reproductive traits. We present data on the effects of dietary thiaminase levels on mortality, yolk conversion efficiency, specific growth rate and sperm quality.

Supervisor: Dr. Dr. Zoë Lindo

In Boreal peatlands, where aboveground plants literally become belowground soil, there is great opportunity for strong plant-soil relationships to arise. Boreal peatlands are important ecosystems due to high carbon sequestration and slow decomposition driven by cool and moist conditions and nutrient-poor plants. My research explores the intimate linkage between aboveground and belowground that shapes peatland properties and dictates decompositional processes. In an observational study, I show how plant-soil feedbacks between plant traits of the dominant ecosystem engineer and the peat environment drive ‘slow’ or ‘fast’ cycles that characterise two peatland types. In those same peatlands, through a reciprocal transplant using plant litter of two dominant plants I show that plant litter was decomposed more efficiently at its site of origin consistent with a home-field advantage.

Supervisor: Dr. David Roy Smith

Organelle genomes are the most sequenced type of chromosome. Next generation sequencing (NGS) has been generating unprecedented amounts of genomic and transcriptomic data that are publicly available, but underused to investigate organelle genome evolution - most of the NGS data is generated for the study of cell nucleus only. We employed this untapped data source to investigate the transcription of organelle genomes in plastid-bearing protists. We mapped RNA-seq reads over 116 protists' mitochondrial and plastid genomes; 77 out of 116 species had their organelle genomes nearly entirely (> 85%) recovered from transcripts despite of the amount of non-coding DNA (intergenic regions and introns) they had. Therefore, polycistronic and/or pervasive transcription seemed to be the norm, regardless the genome structure. In this talk, I will show how publicly available RNA-seq data can be used to investigate organelle genome transcription and argue how current technologies are being underused to characterize organelle genomes.

Supervisor: Dr. Nusha Keyghobadi

The effect land cover has on dispersal is a key question in landscape ecology and it is important to understand just how well genetic variables and dispersal correspond. I compare the relationships of dispersal and population genetic structure using a resistance mapping approach. I analyze genetic and dispersal data from populations of the butterfly Parnassius smintheus, on Jumpingpound Ridge in Kananaskis. I use a resistance surface map of the study area generated in ArcGIS. This surface is analyzed in Circuitscape to derive resistance distances between butterfly habitats that will be correlated separately with historical mark-recapture dispersal and genetic data from this landscape. With a better understanding of how resistance surfaces reflect dispersal and genetic differentiation, we can better interpret the results of landscape genetic studies.

Supervisors: Dr. Liana Zanette

Predators affect prey populations not only through direct killing, but also through the perception of predation risk. Responding to predator threats is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to the population level. My research focuses on the lasting effects of predator ‘fear’ on the avian brain. Using auditory playbacks to manipulate perceived predation risk in black-capped chickadees (Poecile atricapillus) in acoustic isolation and brown-headed cowbirds (Molothrus ater) in large outdoor aviaries, I found short and long term behavioural changes in individuals exposed to increased predation risk. My research connects laboratory methods used to quantify the effects of fear in the brain with behavioural changes found from perceived predation risk in the field.

Supervisor: Dr. Zoe Lindo

Food webs are important conceptual tools for illustrating feeding relationships among species, revealing energy flow, diversity and community structure. Although decomposition, nutrient cycling and carbon sequestration are processes happening in below ground environments, soil food webs are understudied compared to above ground terrestrial or aquatic systems. In addition, the ecosystem level processes of soil systems as emergent properties of soil food webs are affected by global change. My research will examine how soil food webs and ecosystem processes respond to increasing temperature, nutrients, atmospheric CO2 concentration and predator addition. I will perform both lab experiments using mesocosms as well as field experiments.

Supervisors: Dr. Bryan Neff

Atlantic salmon (Salmo salar) were once abundant in Lake Ontario but were extirpated by 1900. Recent stocking programs have had low success, possibly because of a mismatch between the thermal environment in Lake Ontario and the thermal performance of the stocked salmon. Thermal performance curves (TPC’s) describe the effect of temperature on biological processes, and can be a useful tool for understanding the fitness of animals in different thermal environments. My thesis will use TPC’s to examine three metrics of performance in Atlantic salmon: burst swim speed, feeding rate and heart rate. I will compare these metrics across three populations and two rearing temperatures and explore the relationship between these metrics and thermal preferences. Together these data will be used to inform stocking programs.

Supervisor: Dr. Bryan Neff

Disruptive natural selection related to foraging tactics has been recognized as a key factor to the initial stages of species divergence within populations. Pumpkinseed sunfish (Lepomis gibbosus) provide an excellent study system for disruptive selection, as resource-mediated intraspecific competition has been shown to drive divergence between foraging ecomorphs (subset of individuals within populations that that have distinct ecological diet and morphological features). This variation in feeding ecology may lead the ecomorphs to be exposed to different parasites. In theory, variation in parasite communities in different foraging habitats may drive divergent selection on hosts and may promote speciation. I will use pumpkinseed sunfish to examine the role of parasites on MHC and test whether these differences in parasite communities have caused divergent MHC genotypes between pumpkinseed ecomorphs.

Supervisors: Dr. Yolanda Morbey and Dr. Bryan Neff

Throughout their lifetimes, juvenile Atlantic salmon (Salmo salar) are under constant threat from predators and have thus evolved several predator avoidance behaviors, such as utilizing shelters. Despite shelter use being an important behavior against predation risk, how shelter availability modifies this behavior has been understudied and represents a management gap in the conservation of stream fishes. My research aims to examine how shelter availability affects the activity timing of Atlantic salmon and to examine if there are population differences in this behavior. I will be observing the behavior of juvenile Atlantic salmon from three populations held in net pens in a natural creek to determine how high and low shelter conditions influence juvenile behavior.

Supervisor: Dr. Keith Hobson

Avian species breeding within agricultural landscapes have experienced declines worldwide. Studies have shown a linkage to increasing agricultural intensification which may influence prey insects. Nestling body condition is an important predictor of survival and is directly related to diet. Barn Swallows (Hirundo rustica) are a threatened, agriculturally associated, aerial insectivore species which makes them highly reliant on prey insects. My research aims to examine reproductive success in Barn Swallows breeding in a diverse landscape, focusing on the effects of nestling diet. I will sample breeding colonies that vary in degree of agricultural intensity, measuring nestling diet via DNA barcoding of fecal samples and stable isotopic analysis. This information will further our understanding of the mechanisms resulting in observed declines of a threatened aerial insectivore species.

Supervisor: Dr. Charles Trick

The complex interaction between factors, such as increased eutrophication, temperature and salinity, may help explain harmful algal bloom (HAB) prevalence. Heterosigma akashiwo is a prominent marine species that episodically forms HABs. H. akashiwo is a microscopic alga of the class Raphidophyceae, aptly named for causing red tides in coastal waters. It has been indicted for extensive fish mortality resulting in major economic losses for commercial fishing and aquaculture industries. Management of H. akashiwo blooms is challenging as the cause of toxicity is unclear. I will be comparing the growth and toxicity of different strains of H. akashiwo. My research aims to compare the growth and toxicity between strains of H. akashiwo, isolated from different geographic locations, under a suite of temperature and salinity regimes.

Supervisor: Dr. Irena Creed

Wetland restoration has increased over the last few decades as the importance of wetlands on the landscape has been recognized for their role in flood abatement, carbon sequestration, and habitat provisioning. Research suggests that vegetation structure might not be the best determination of restoration success. Rather, a functional look a plant communities through plant functional traits, has been suggested as a better method for evaluating wetland restorations and may provide insight into the functional recovery of wetland systems. My research aims to analyse plant functional traits of a wetland restoration chronosequence to understand how ecosystem processes change with time since restoration.

Supervisor: Dr. Amanda Moehring

An organism’s ability to recognize and mate only with conspecific individuals is vital to maximize their reproductive success and offspring’s fitness. I will study the genetic basis of mate recognition and female rejection behaviours by using two Drosophila species, Drosophila simulans (sim) and Drosophila melanogaster (mel). I will determine if katanin-60, a microtubule-severing protein, affects female rejection of heterospecifics. I will use the CRISPR/Cas9 system to produce hybrids that lack either the mel or sim allele to see if this results in mel-like or sim-like behavior. I will also use RNAi in conjunction with the UAS/Gal4 system to identify which brain regions contribute to female rejection behaviours. Understanding the genes affecting mate recognition and rejection would give us greater insight into how speciation occurs.

Supervisor: Dr. Keith Hobson

Due to the difficulty of tracking small birds, the post-fledging period is one of the least understood stages of the avian life cycle. This period also represents a time of strong selective pressure for juvenile migratory songbirds resulting in significant population bottlenecks. Barn Swallows (Hirundo rustica) are a threatened long distance migrant and little is known about the fate of juveniles once they leave the nest, especially in North America. Making use of automated radio telemetry (Motus), I hope to track the post-fledging survival and movements of juvenile Barn Swallows in Southern Ontario. The use of the existing Motus infrastructure in southern Ontario allows for a novel approach for measuring survival of this threatened species and provides the means for insight into their pre-migratory movements.

Supervisors: Dr. Elizabeth Gillies & Dr. Hugh Henry

Asynchronies between fertilizer application and crop nutrient demand have led to over-fertilization and increased soil nitrogen leaching from agricultural fields. The use of stimuli-responsive biodegradable polymers for the coating of fertilizers offers a more targeted delivery mechanism, which could increase nutrient use efficiency and reduce soil nutrient losses. I have been working with a redefined class of triggable polymers (poly(ethyl glyoxylate)) that are designed to go through end-end depolymerization after the protective end cap on the polymer is cleaved off by a specific stimulus. I aim to develop an end cap that can be cleaved off by specific plant-root specific stimuli, which would allow for controlled and targeted release of fertilizer pellets.

Supervisor: Dr. Scott Petrie Co-Supervisor: Dr. Christopher Guglielmo

Spatial and temporal use of habitats by animals is influenced by a variety of associated benefits and costs. The Lake St. Clair region provides a diversity of habitat management and conservation strategies that are ideal to investigate how waterfowl movements and foraging strategies vary in response to human disturbance (e.g., hunting), habitat quality, and food availability across the landscape. My objective was to evaluate resource selection of adult female mallards (Anas platyrhynchos) in relation to perceived risk and to determine if resource selection influences survival during autumn and winter. Preliminary results indicate that resource selection strategies of adult female mallards were influenced by the composition habitats categorized by land classification and ownership type while survival appears to be independent of these variables.

Supervisor: Dr. Yolanda Morbey & Dr. Chris Guglielmo

Seasonal migration is a common part of life for many North American bird species. Many of these species exhibit differential migration, where the spatial and temporal attributes of migration differ between groups of individuals within the same population. Differential migration is believed to result from multiple mechanisms, however the relative importance of these mechanisms is still uncertain. In this talk, I will discuss my upcoming research that will examine several mechanisms believed to influence migratory timing in birds. Using the White-throated Sparrow (Zonotrichia albicolis), a species known to display male-first differential migration, I will compare mechanisms between sexes and behaviourally distinct plumage morphs. These plumage morphs are genetically linked and allow for inferences regarding how the mechanisms underlying differential migration are effected by behaviour.

Supervisor: Dr. Amanda Moehring

The complex processes that regulate mate preference have been widely studied. Most studies to date have focused on the mechanisms that drive male mate choice, while those that underlie female mate preference remain largely unknown. Recent studies show that females in most species are the primary discerners of reproductive receptivity. In order to address the existing knowledge-gap, a combination of genetic tools will be employed, including temperature-sensitive gene disruption, in both D. melanogaster and D. simulans females to isolate regions of the brain responsible for female sexual receptivity or rejection. Identifying the neural basis of female receptivity, while of interest in its own right, will also contribute to our understanding of the origin of speciation and how neuronal circuits integrate multiple sources of information from various modalities to subsequently produce directed behaviours.

Supervisor: Dr. Ian Scott & Graham Thompson

With global food security becoming increasingly important, and insecticide resistance on the rise, new insect pest management strategies need to be considered. One technology that shows potential is RNA interference, which silences target gene expression and can result in development delays, decreases in insecticide resistance, and lethality to pests. Other alternatives are trap crops, which attract pest species using either visual or olfactory cues. By targeting the olfactory senses, an attractant or arrestant effect can be observed; this has been seen in Trialeurodes vaporariorum (Westwood) using transgenic Micro-Tom tomatoes (Solanum lycopersicum) with enhanced carotenoid cleaving deoxygenase gene activity. By combining these attractive plants with RNA interference, a novel lethal trap crop model, which lures, and then kills by silencing vital gene targets, can be developed.

Supervisor: Dr. David Sherry

Harsh Climates can cause avian populations to endure stressful conditions for extended periods of time. Black-capped chickadees (Poecile atricapillus) inhabit much of North America, including southern Ontario, and are subjected to local winter conditions for several months of the year. Previous studies have shown that populations of birds inhabiting harsh climates benefit from advanced cognitive function. These benefits are found in populations from different geographic regions, testing components of harshness such as latitude and altitude. Though temperature is closely related to other components of harshness, few studies have isolated temperature. Here, I examine local populations to assess the impact of harsh seasonal winters on cognition.

Supervisor: Dr. Amanda Moehring

The type and quantity of cuticular hydrocarbons (CHCs) expressed by Drosophila are determined by the complex interplay between the fly’s genetic background, its diet, and the commensal microbes that colonize its gut. Since the CHC profile of a fly is intrinsically linked to its reproductive fitness, alterations to the fly’s profile due to input from any of these mechanisms can potentially lead to reproductive isolation and eventual speciation. Using genetic and molecular techniques, this study aims to separate out and independently examine each of the factors contributing to CHC variation in Drosophila in order to better understand the mechanisms that may give rise to behavioural isolation and speciation in insects.

Supervisor: Dr. Graham Thompson

In honey bee colonies the queen signals fecundity to her worker daughters via ovary-inhibiting queen pheromone, which renders them conditionally sterile. There is interest in identifying genes and neural circuits regulating this type of reproductive signalling, but honey bees are not ideal models in neuroimaging. In my study, I use Drosophila as an established behavioural genetic model to map neurons that respond to the queen bee’s ovary inhibiting pheromone. To do so, I use a calcium-channel activated neural imagining technique that allows me to identify pheromone-activated neurons within antennae. Through confocal imaging I have identified olfactory receptor neurons Or-49b, Or-56a and Or-98a as responsive to the social pheromone, and identify functional homologues of each receptor in the bee itself.

Supervisors: Drs. Greg Thorn and Zoë Lindo

Peatlands have an important role in global climate change through sequestration of atmospheric CO2. There is concern that altered fungal community function affected by climate change may turn peatlands from carbon sinks to carbon sources, greatly exacerbating the impacts of climate change. In order to gain a better insight into effects of climate change on the structure and function of these ecosystems, my research has focused on diversity and structure of fungal communities in natural environment in boreal peatlands and in mesocosm experiments to better understand the main and interactive effects of multiple drivers of climate change on fungal communities, and their function. These studies could help to provide a broader conceptual context of climate change and its consequences for carbon dynamics of boreal peatlands. .

Supervisor – Dr. Zoë Lindo

It is estimated that the last 200 years has seen the loss of 99% of North American grasslands through conversion to agriculture. In southern Ontario, urban and agricultural landscapes have replaced all but fragments of tallgrass prairie habitat. Currently, grassland restoration initiatives convert land, such as former agricultural fields, to restored grasslands. However, many of the areas targeted for restoration are small, isolated patches surrounded by active agriculture or forested areas. My project looks at such restored grasslands, planted by Nature Conservancy Canada, where I measured plant diversity in association with environmental variables at varying distances from adjacent forest and agriculture, in order to explain patterns in plant composition. This research could inform future restoration plantings and help determine minimum grassland patch sizes.

Supervisor: Dr.Nusha Keyghobadi and Dr. Brock Fenton

Many parasites rely on their hosts for dispersal, and we thus expect their movements to be linked. However, it was recently emphasized that generalist ectoparasites and highly mobile hosts might display very different gene flow patterns. In my project, I wanted to see how similar gene flow patterns are between Cimex adjunctus, a generalist ectoparasite of bats, and its bat hosts. In the same genus as C. adjunctus, few species are associated with humans, and others with swallows. Parasite species may display genetic signature representative of the host with which they associate. In my project, I also wanted to know how hosts affect neutral and adaptive genetic variation in generalist ectoparasites. Overall, I found that hosts clearly affect their parasites, but sometimes in unusual ways.

Supervisor – Dr. Beth MacDougall-Shackleton

Major histocompatibility complex (MHC) genetic diversity is maintained largely by pathogen-mediated selection and sexual selection should favour the ability to assess MHC. MHC genotype is assessed via olfaction in several taxa, but this has been largely overlooked in birds. Recent evidence indicates that MHC-genotype and preen oil composition are correlated, but whether birds use this information to assess potential mates is unknown. MHC heterozygosity has also been linked to disease resistance, and preen oil odour thus provides a compelling potential mechanism for both MHC-based mate choice and disease avoidance. I will test whether song sparrows (Melospiza melodia) use preen oil odour to preferentially associate with both MHC-dissimilar and uninfected conspecifics. My research may reveal that chemical communication in birds is more common than previously believed.

Supervisor: Dr. Liana Zanette

Poaching drives biodiversity loss, yet there have been no means to systematically quantify its extent. Current methods are fraught with problems ranging from low statistical robustness to unreliable answers given by suspected poachers. I use an automated camera and playback system that when triggered by motion broadcasts a sound, and films the animal’s reaction, to experimentally quantify the level of fear poaching cues (sound of humans speaking, dogs barking) and a non-threatening noise (insects) inspire in a Ugandan wildlife community. Animals reacted fearfully to dogs by significantly fleeing and exhibiting more vigilance during dog playbacks, indicative of high poaching intensity, as dogs enter wildlife areas only in the company of poachers. Following validation, I will use the methodology to quantify poaching in a temperate system.

Supervisor: Dr. Graham Thompson
Termites are eusocial insects that live in kin-based colonies, where a small number of reproductives are supported by a large number of subfertile workers and soldiers. Some of this variation in caste phenotype may be explained by genes that regulate individual development in a caste-specific manner. I tested this hypothesis by using mRNA-seq analysis to detect the presence and expression of protein encoding genes in the worker, soldier, and reproductive nymph castes of the Eastern subterranean termite. I assembled a transcriptome from nine sequence libraries derived from three reproductively isolated populations, and provisionally annotated 29461 transcripts for gene function. Using this transcriptomic data, I identified 141 genes that are uniquely expressed by caste. This gene set contains several regulators of development such as hexamerins and a growth arrest protein. My finding helps to clarify the genetic basis of caste differentiation in a common pest species of subterranean termite.

Personal information:
I became fascinated with insects during my previous employment with the Canadian National Collection of Insects. At the same time, I also saw the emergence of large data genomic technology being used to answer evolutionary questions. When I decided to pursue a master’s degree, I wanted a project that would combine both of my interests. During my stay here at °ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â, I started the Mustang Bioinformatics Club with Jantina Toxopeus to provide other graduate students with bioinformatic support.

Supervisor – Dr. Ian Scott Co-Supervisor – Dr. Jeremy McNeil

Insecticide resistance continues to develop as a problem within agricultural systems. New non-chemical routes of pest reduction are required to reduce pest populations and increase agricultural yield in response to rising levels of resistance. Trichoplusia ni (Hübner) (Cabbage Looper Moth) is a problematic agricultural pest in standard agriculture, and greenhouses, with a wide range of possible host plants including cabbage, tomato, and bell peppers. They have developed resistance to a number of pest management strategies, and serve as a model organism in this study of LeCCD1 transgenic Solanum lycopersicum (L) (tomato) trap crop capabilities. Trap cropping is the practice of planting highly attractive, disposable plants within the grow area of a main crop with the purpose of drawing pests away from harvested plants. This design aims to verify Cabbage Looper Moth attractance to LeCCD1 tomatoes, as well as assess trap crop effectiveness against this pest in model growing arrangements.

Supervisor: Dr. Liana Zanette
Predators affect prey populations not only through direct killing, but also through the perception of predation risk.  Responding to predator threats is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to the population level.  My research focuses on the lasting effects of predator ‘fear’ on the avian brain.  I will be using auditory playbacks to manipulate predation risk in black-capped chickadees (Poecile atricapillus) in acoustic isolation and brown-headed cowbirds (Molothrus ater) in large outdoor aviaries. I will be looking for long lasting changes in brain morphology and activation in regions thought to be involved in the avian fear network.  My research aims to connect laboratory methods used to quantify the effects of fear in the brain with behavioural and physiological changes found from perceived predation risk in the field.

Supervisor: Bryan Neff
The major histocompatibility (MHC) genes encode cell-surface proteins that are responsible for presenting antigen peptides to immune cells. Aside from its vital immune function, the highly variable MHC genes have also been linked to mate choice in multiple species. One hypothesis is that females of some species choose their mates based on dissimilarity at the MHC in order to produce heterozygous offspring with improved immunocompetence. I will use bluegill (Lepomis macrochirus) as a study species for MHC-based mate choice. The MHC regions of bluegill mating pairs caught in the act of spawning will be investigated using next gen sequencing techniques.

Supervisors: J.N. McNeil, K.A. Hobson
Temperature is a major abiotic factor determining distribution and population dynamics of insects. Seasonal changes in temperature are also important cues related to habitat quality and when decreasing temperature (and shortening daylength) indicate impending habitat deterioration insects enter diapause locally until conditions improve or emigrate elsewhere.  However, increased variability in temperature conditions as a result of climate change may significantly impact the distribution and seasonal biology of beneficial and pest species.
Fields and McNeil (1984) showed the true armyworm, a sporadic pest, did not overwinter in Canada but immigrated in each spring. However, there are now more frequent suggesting there may be local overwintering populations. I repeated their experiments and found armyworm still cannot survive here. Therefore, I propose using stable isotopes to examine the origin of immigrants, testing the hypothesis that the higher frequency of outbreaks is the result of armyworm populations overwintering further north than in the past.

Supervisor: David Roy Smith
Mitochondria and plastids originated from independent endosymbiotic events over 1.5 billion years ago. These organelles evolved and kept their genetic material. The first organelle chromosomes to be sequenced were circular and relatively simple. However, in the last 30 years of organelle genetics, mitochondrial and plastids genomes proved to be widely diverse in size, content and structure. The modes of organelle genome transcription are similarly variable and difficult to explain under purely adaptive forces. Here, I will present how intricate organelle transcription can be, particularly in protists. I will also argue how current technologies are being underused to better characterize these processes and what we can do to overcome it.
A bit about me: I was raised in a farm, which brought me to Biology. Luckily, I attended a school purely based on Evolution (University of Sao Paulo, campus Ribeirao Preto). Then, my passion for evolutionary biology just kept increasing after working in Portugal (with fungi taxonomy at the University of Minho) and Canada (with evolution of aging in Volvox carteri at the University of New Brunswick). Now, Im here at °ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â continuing my path on evolutionary biology.

Supervisors: Yolanda Morbey and Chris Guglielmo
Protandry, meaning “males first”, is a common pattern of sex-biased timing that is seen across a diverse range of animal taxa (insects, amphibians, fish, mammals, and birds). In migratory birds, protandry is the norm, and is apparent in many events leading up to and including arrival at breeding sites. I will be studying the mechanisms underlying protandry in a migratory songbird, the Black-throated Blue Warbler (Setophaga caerulescens). I will capture Black-throated Blue Warblers during fall migration, keep them in captivity over winter, photostimulate them to begin migration, and then radio-tag and release them during spring migration at Long Point, Ontario, to monitor stopover behaviour and timing of departure. This will be the first study to estimate stopover duration in migratory birds with a known arrival date.

Supervisor: Graham Thompson
Social insects often communicate reproductive roles through pheromones. In honey bee colonies both drone and worker castes cue their reproductive behaviour from queen mandibular pheromone. Drones are sexually attracted to pheromone-emitting virgin queens, while workers respond to this same pheromone with selfless reproductive help. Studies within our lab suggest that this multi-purpose reproductive signal is inadvertently effective on nonspecific recipients, and may elicit comparable responses from male and female non-social insects. Remarkably, QMP de-activates Drosophila ovaries, much as it does in workers. QMP may also accelerate mating effort by males, as it normally does with drones. In the present study, I build on these bee-fly comparisons to test if male or female flies are positively attracted to volatile QMP, and further use the fly model (NFAT) to map the neural receptors that mediate this behavioural response.

MSc candidate
Supervisor: Dr. Zoë Lindo
Boreal peatlands are ecosystems that are receiving heightened interest due to their large carbon sequestration abilities and low decomposition rates, making them significant sinks of carbon. There is a growing body of literature that suggests aboveground-belowground linkages, or plant-soil interactions, are important for ecosystem functioning and integral to the delivery of ecosystem services like carbon and nutrient cycling. Trait-based approaches in ecology are being increasingly used to quantify functional diversity of organisms to elucidate ecosystem functioning, and aim to understand how plants respond to environmental conditions and effect processes. Examining aboveground-belowground linkages with a traits-based approach in the context of peatlands allows for novel examination of traditional questions, like how are plant communities shaped by the environment, and how do plants influence ecosystem process like decomposition? My master’s project explores these questions by performing an observational study linking plant species to soil variables, and two reciprocal litterbag transplant experiments testing for decomposer-litter affinities.
A bit about me: My passion for peatland research was cultivated during a stint at the Ontario Ministry of Natural Resources and Forestry in Sault Ste Marie, where I participated in peat collection and permafrost coring, and also met Dr. Lindo conducting this field work.

Supervisor: Dr. Liana Zanette  
Predators  not only kill prey, but through the 'fear' of predators induce costly anti-predatory responses.  These anti-predatory costs among prey individuals, may scale up to effects on prey populations as a whole, through effects on prey reproduction, juvenile survival, and/or adult survival.  My thesis focuses on how the perceived risk of predation affects prey population dynamics through effects on juveniles.  I monitored the fate of juvenile song sparrows (Melospiza melodia) reared in environments manipulated with audio playbacks to be perceived as either a high or low predation risk environment. Scared juveniles had lower survival compared to juveniles reared in a low risk environment.  Furthermore, scared juvenile survivors were in poorer condition which may have adverse, possibly even lifelong effects.  Demonstrating that the fear of predators can have a greater net effect on wildlife prey populations than we previously showed with reductions in offspring production alone.

Supervisor: Nusha Keyghobadi
Due to the current rate of climate change and the warming patterns it has caused, in many alpine habitats the treeline is ascending towards the normally colder mountain peaks. This results in shrinking alpine habitats and fragmentation of existing populations of local organisms. For the purpose of conservation, it is imperative to understand the effects of individual landscape elements on the dispersal of organisms. My project entails creating resistance surface map models in ArcGIS to examine the effects of the landscape on movement and gene flow among populations of alpine butterfly Parnassius smintheusin Kananaskis, Alberta. The variables of interest are land cover type and elevation changes, and these will be used to create an isolation by resistance model. With this model, areas of high connectivity and traffic can be determined and targeted for conservation purposes.

Climate change is expected to increase atmospheric CO₂ levels and global temperatures. In Boreal peatlands, increased temperature is expected to directly increase decomposition rates, but also indirectly through changes in plant species composition and litter inputs. I used three species of peatland plants grown at 430 ppm and 750 ppm CO₂ for a year to quantify litter decomposability and carbon release. My results suggest that predicted changes in plant species composition may increase decomposition rates and labile carbon inputs to soil systems. However at the same time, plants grown under elevated CO₂ demonstrated reduced labile carbon inputs. Understanding decomposition processes in Boreal peatlands under future climate scenarios will help predict whether these systems will remain a carbon sink or possibly become a global carbon source.

Termites, as social insects live in kin-based colonies with defined boundaries that are generally actively defended against intruders, including individuals from conspecific colonies based on chemical signatures. However, the eastern subterranean termite (Reticulitermes flavipes) was accidentally introduced into Toronto where it forms expansive supercolonies that differ from the separate colonies observed in their native range. In addition there are now colony locales in southwestern Ontario with significant genetic differences.  It has been argued that in habitats with limited resources the benefits of sharing outweigh the costs of aggressive defense. Therefore, using a behavior based study I tested the hypothesis that intra-specific aggression varies with geographic distance. I found no evidence of overt aggressive behavior between individuals from Toronto (supercolonies) or Pelee (separate). However, it was evident that workers from Toronto and Pelee did not mix in an assay where they shared a common food resource, which indicates that social order is still maintained, possibly through cuticular hydrocarbon profiles. 

Supervisor: Bryan Neff
Atlantic salmon (Salmo salar) were once abundant in Lake Ontario, but were extirpated by 1898. Efforts to reintroduce Atlantic salmon into Lake Ontario have not yet succeeded. One potential obstacle is the introduction of invasive forage fish, which can lead to a thiamine deficiency in salmonids. Previous studies on thiamine deficiency have documented negative effects, including lower swimming performance and body condition. To study the effects of thiamine deficiency, our salmon have been fed either a high-thiamine diet or a low-thiamine diet. Three populations of Atlantic salmon will be used to determine which strain has the best performance under a low-thiamine diet. Crosses will be done to investigate the effects of thiamine deficiency on reproduction, including hatching success and survival. Results will provide insight into which population may be better suited to the current environmental conditions of Lake Ontario, and how to manage the reintroduction efforts of Atlantic salmon.

Supervisor: Brian Branfireun
Northern peatlands disproportionately contribute methylmercury, a bioaccumulating and biomagnifying neurotoxin and endocrine disruptor, to aquatic biota in downstream waters ultimately affecting humans. Sulphate reducing bacteria (obligate anaerobes) are mainly responsible for methylmercury production in anoxic peat soils. The production of methylmercury is largely controlled by the availability of sulphate reduction reactants (sulphate as an electron-acceptor, a labile carbon substrate and bioavailable mercury), whereas the specific hydrologic properties of any particular peatland control transport. The effects of climate change may enhance the production and transport of methylmercury in northern peatlands. Using two field investigations: (1) measuring the response of in situ net methylmercury production under experimentally heated soil treatments in two northern peatlands and (2) determining the hydrologic connection between two streams draining a peatland, will provide researchers, land managers, and policy makers greater understanding of methylmercury production and transport in northern peatland ecosystems.

Supervisors: Ian Scott & Graham Thompson
In today's day and age, food is being produced at an arithmetic rate while human population is growing at an exponential rate, making crop yield and protection increasingly important. Currently, insect pests and pathogens are responsible for approximately 25-30% of crop loss. In addition, the incidence of pesticide resistance is also increasing, further threatening crop yield. The use of RNA interference (RNAi) is one promising means of pest management where double-stranded RNA (dsRNA) silences the messenger RNA (mRNA) of a target based on the genetic sequence selected, resulting in lethality and developmental delays. By utilizing RNAi, applying it to transgenic Micro-Tom tomatoes (Solanum lycopersicum cv.), which have a high attraction for the greenhouse whitefly (Trialeurodes vaporariorum), a new efficient trap crop may be developed. This may be the next step in pest management and in the phasing out of chemical pesticides and insecticides.

Genetic diversity is critical in shaping the adaptive capacity of avian populations and the fitness of individuals. Genome-wide heterozygosity is usually assessed using selectively neutral markers such as microsatellites. However, neutral-locus heterozygosity may not accurately reflect heterozygosity at protein-coding sites that may be under selective pressure. The major histocompatibility complex (MHC) is the most polymorphic region in the vertebrate genome. Additionally, MHC diversity is found to be associated with immunocompetence, which is related to survivorship. DNA samples were collected from a population of Song Sparrows (Melospiza melodia) and analyzed to assess heterozygosity at 12 microsatellites. Birds were genotyped at MHC class II b using the Illumina MiSeq platform. Our results show that microsatellite heterozygosity does not predict MHC diversity. We also found that MHC allele number did not correlate with overwinter. This information will aid in conservation and management decisions when determining how to properly assess genetic diversity of endangered populations.

Vegetative reproduction utilizes stem, leaf, or root derived organs to form clonal offspring and is an inherent feature of the body plans of many plants.   Growth allocation often favours vegetative organ production over that of sexual reproduction and the depth of clonal organs can aid in freezing avoidance. Frost tolerance decreases dependence upon site availability and recruitment can be facilitated by the greater supply of resources to clonal offspring.
To test the effects of freezing on vegetative organ survival and plant recruitment I will use snow removal, freezing, and functional trait analysis.  Plants will be subjected to freezing temperatures after which organ survival, recruitment, and organ investment will be measured.  Snow removal and freezing chambers will be used to study the effects of organ depth.  Functional trait literature, phylogenetic information, and geographic distribution will also be used to gain further insight on the distribution and qualities of these functional traits.

Choosing the right mate is of central importance to biological fitness. In Drosophila, olfactory and gustatory cues in the form of cuticular hydrocarbons (CHCs) are used to assess the identity and quality of potential mates. Since Drosophila melanogaster produces infertile offspring when it forms hybrids with any of its sister species, those individuals which are the most discriminating against flies that do not express the appropriate CHC profile will have the highest fitness, as they will preferentially mate with individuals of the same species to form fertile offspring. Here, I will endeavour to identify key genes involved in species differences in CHC production. Since different CHC profiles constitute a reproductive barrier across Drosophila species, genes identified in this study will provide insight into the complex mechanisms of speciation in insects.

MSc. candidate
Supervisor: Dr. Charles Trick
Fish-killing flagellates are comprised of a taxonomically diverse set of Protists. Yet, the mechanisms by which these cells purportedly kill fish are fairly common. These HAB species can have dramatic effects on the aquaculture and fishery industries. The mass mortality of the affected marine organisms may result from individual or multiple toxic mechanisms. As Prymnesium parvum is a potentially invasive species, knowledge on the factors that shift the bloom from non-toxic to toxic is critical to our ability to predict the consequences of new or established blooms. For my project, I will be investigating the effects of light, temperature, salinity, macronutrients and micronutrients on toxin production in Prymnesium parvum.

Supervisor: David Sherry
Harsh Climates can cause avian populations to endure stressful conditions for extended periods of time. Black-capped chickadees (Poecile atricapillus) inhabit much of North America, including southern Ontario, and are subjected to local winter conditions for several months of the year.  Previous studies have shown that populations of birds inhabiting harsh climates benefit from advanced cognitive function. These benefits are found in populations from different geographic regions, by testing components of harshness such as latitude and altitude. Though temperature is closely related to other components of harshness, few studies have isolated temperature. Here, I examine local populations to assess the impact of seasonal temperatures on cognition. Environmental cues play a significant role in seasonal changes experienced by chickadees. These changes include changes within the brain.  By simulating different seasonal temperatures, I hope to find a relationship between seasonal conditions and cognitive functions in black-capped chickadees.

Supervisor: Dr. Hugh Henry
Cross-protection is a phenomenon that occurs when exposure to one stress increases tolerance to a second different stress. Both frost and drought result in cellular dehydration and there are similar increases in protective compounds, but it is currently unknown whether exposure to frost can increase the survival and growth of plants under drought. Poa pratensis was frozen at 0, -5 or -10 for 3 d in the fall or spring and then subjected to no drought, a moderate drought, or a severe drought for 3 weeks in the summer. There was a significant interaction between frost and drought stress, where freezing resulted in higher survival, biomass and relative growth rates under severe drought. However, this interaction did not appear to be related to the retention of soluble sugars after freezing.

Supervisor: Dr. Greg Thorn
Tall grass prairies are known for their drastic reduction across North America and there is great interest in restoring them via conversion from agricultural land. Large-scale ecological studies of soil organisms have been greatly facilitated by the advent of high throughput sequencing. The Agaricomycetes are class of fungi found in prairie soils, best known for producing macro scale fruiting bodies or “mushrooms”. My study uses both mushroom and soil sequence data from prairies in various stages of recovery since agricultural use. Which factors drive prairie Agaricomycete composition? Years since tillage, dominant plants, soil minerals & organic matter, and geographic location will be considered. In the process, tall grass prairies in Ontario can be characterized by their mushroom diversity and comparisons will be made between my two sampling methods (mushroom collection vs. soil sequencing). This will lead to insights into fungal community succession, prairie restoration, and the natural history of our grasslands.

Evolutionary biologists have long been interested in understanding how mating patterns contribute to fitness, and specifically the effects of genetic compatibility on mate choice and offspring viability. Genetic compatibility has been previously linked to the effects of specific genes of large effect, such as the major histocompatibility complex (MHC). MHC heterozygosity improves resistance to pathogens (Hedrick, 2002) and mating preferences have been shown to increase offspring MHC heterozygosity (Penn & Potts, 1999). In broader terms, genetic compatibility has been linked to overall genetic relatedness between mates and/or populations. At one extreme, inbreeding effects between closely related mates can reduce the fitness of offspring through the loss of heterozygosity and expression of deleterious recessive alleles (Lynch & Walsh, 1998). At the other extreme, outbreeding effects between distantly related mates can reduce the fitness of offspring through genetic incompatibility and disruption of co-adapted gene complexes (Lynch, 1991). When observed as a continuum with inbreeding and outbreeding as the extremes, the effects are expected to produce a function where the highest fitness occurs at intermediate levels of genetic relatedness between mates (Figure 1). A stronger understanding of this relationship is of interest to evolutionary biologists, and can provide practical information about optimal relatedness levels that can be used to guide conservation and agriculture programs that aim to rescue or enhance inbred populations via outbreeding.

It is estimated that the last 200 years has seen the loss of 99% of North American grasslands through conversion to agriculture. In southern Ontario, urban and agricultural landscapes have replaced all but fragments of tallgrass prairie habitat. Currently, grassland restoration initiatives convert land, such as former agricultural fields, to restored grasslands. However, many of the areas targeted for restoration are small, isolated patches surrounded by active agriculture or forested areas. My project looks at such restored grasslands, planted by Nature Conservancy Canada, that are bordered by active agricultural fields and forest fragments in Norfolk County.  I will quantify plant diversity and soil faunal diversity at varying distances from grassland borders, in association with environmental variables and functional traits. This research could inform restoration processes through determination of patch size as influenced by land cover. The use of plant and faunal functional traits could provide new perspectives for restoration initiatives.

Scott/McNeil group
Generalist insect herbivores utilise visual, chemical and tactile cues to locate host plants. However, generalist soil-dwelling herbivores rely most on chemical cues in order to detect suitable and avoid unsuitable plants. Wireworms (Coleoptera: Elateridae) are generalists and are serious pests of many agricultural crops; thus requiring pest management strategies. Preliminary studies observed reduced wireworm densities (genus Agriotes) after buckwheat (Fagopyrum esculentum) is used as a cover crop; potentially due to the plant releasing repellent, antifeedant and/or toxic chemicals into the soil. I will explore the different potential effects of chemicals from buckwheat roots on wireworm behaviour, using a six arm olfactometer and small plot experiments.  My results will be the basis for subsequent chemical analyses, as these compounds could offer an alternate management strategy.

Moehring group
The complex processes that regulate mate preference have been widely studied. Most studies to date have focused on the mechanisms that drive male mate choice, while those that underlie female mate preference remain largely unknown, yet females are the primary discerners of reproductive receptivity in most species. In order to address the existing knowledge gap we will be utilizing a combination of genetic tools, including temperature-sensitive gene disruption, in both Drosophila melanogaster and Drosophila simulans to isolate regions of the brain responsible for female receptivity or rejection. We will then assess the contribution of these neural region(s) to behaviour in the context of three candidate genes that have previously been identified as contributing to female mate preference in order to assess whether each gene acts via the same neural region. Identifying the neural basis of female receptivity, while of interest in its own right, will also contribute to our understanding of how neuronal circuits integrate multiple sources of information from various modalities to subsequently produce directed behavior

Co-Supervisors: Dr. Scott Petrie and Dr. Hugh Henry
Degree Sought : MSc
An essential component of wildlife management and applied ecology is to understand how animals use habitat. Examining how an animal may select habitat can shed light on complex behavioural processes and their associated influence on fitness. Knowledge of how wood ducks and their broods move throughout their landscape, select habitats, and survive is valuable information for wildlife managers and ecologists. Duckling survival has a strong relationship with recruitment, therefore, population management can be improved through understanding the spatial and temporal dynamics of survival. I used radio-telemetry to monitor female wood ducks and broods to 30 days post-hatch. I determined what types of habitat wood ducks select for and modelled survival based on biotic and abiotic covariates. My research will improve our ecological understanding of wood ducks in Ontario and help refine management practices for nest box programs and brood rearing habitats.

Northern peatlands (a type of wetland) play an important role in accumulating atmospheric CO₂ and storing it as soil C in peat thereby contributing to ‘global cooling’ over the Holocene.  However, climate change is forecasted to be the most extreme in high latitudes where a significant amount of global C is stored in peat.  Enhanced decomposition through warming and possibly drying could result in northern peatlands becoming a net carbon source in the future, resulting in a positive feedback with the atmosphere. There is little experimental research on this question, particularly for fen peatland types even they account for about 50% of the total peatland area in Canada. My objective is to explore how strongly climate will alter peatlands carbon storage (i.e. direction, magnitude and drivers) with evidence from both mesocosm and field experiments in order to better model the fate of carbon in Canadian peatlands and their role in global carbon cycling.

Boreal forest ecosystems are nitrogen (N) limited, but sequester large amounts of carbon (C). Predicted elevated temperatures are expected to increase the demand for N. Moss-cyanobacteria associations (MAC) are a fundamental source for new N inputs through biological N₂ fixation. Although the effect of temperature on these systems and N₂ fixation and the fate of N are poorly understood I hope to  (1) understand the differences in N₂ fixation and growth of Nostoc punctiforme under elevated temperature in isolation and with mosses under controlled laboratory and field conditions and; (2) elucidate whether N₂ fixed by N. punctiforme is preferentially taken up by moss or ‘leaked’ in the ecosystem.

A heterogeneous landscape affects population structure, resulting in both neutral and adaptive genetic differences between populations. Understanding how populations are structured informs predictions about how they will respond to changes in their environment, which is especially important for species that may be vulnerable to climate change. I will examine population structure and adaptive variation in the alpine butterfly Parnassius smintheus in the context of the landscape, using single nucleotide polymorphisms (SNPs) as genetic markers. I will determine how landscape features such as forest cover affect P. smintheus population structure, and whether different landscapes result in adaptive variation. I will also investigate the effects of changing sampling size on calculating population statistics when using SNPs compared to microsatellites, to inform future sample collection.

MSc. Candidate
Supervisor: Dr. Irena Creed
Abstract: Models can be used to forecast large-scale ecological change, but physical processes are often complex and contain hidden frequencies at different times. My goal is to develop models that characterize water discharge across time and space, and relate observed changes to large-scale natural oscillations including the El Nino, North Atlantic, Pacific Decadal and Atlantic Multidecadal Oscillations, which may be affecting water discharge. I use wavelet analysis, which allows me to understand not only which oscillations are occurring but also when they are occurring. By decomposing water discharge time series into frequency and time sub-space, we can relate causes of seasonality to large-scale oscillations. 

I'm guessing that the title and abstract were not announced

Supervisor: Dr. Zoe Lindo
Degree: MSc

Climate change is expected to increase atmospheric carbon dioxide levels and global temperatures. In Boreal peatlands, these changes are expected to directly affect decomposition processes through enhanced microbial activity, and indirectly affect decomposition through changes in litter input and decomposability associated with changes in plant species composition. I will use Sphagnum spp., Carex magellanica and Chamaedaphne calyculata litter. First, I will quantify the decomposability and carbon release of the three species grown under ambient and elevated CO₂. Next, I will investigate how microbial communities use different carbon compounds under different temperature regimes. Finally, I will evaluate the interactive effects of temperature and elevated CO₂ on long-term decomposition. Northern peatlands are carbon sinks; understanding decomposition processes under future climate scenarios will help inform carbon budgets.

Genetic diversity is critical in shaping the adaptive capacity of populations and the fitness of individuals. In vertebrate animals, the Major Histocompatibility Complex (MHC) is the most polymorphic region in the genome and appears to be under strong balancing selection pressure. The adaptive importance of MHC genes makes these loci good candidates for comparing patterns of genetic diversity to those at neutral loci, and for examining the fitness consequences of MHC diversity. My research investigates the degree to which neutral and adaptive loci are correlated in terms of individual genetic diversity, and pairwise genetic similarity, in free-living song sparrows (Melospiza melodia). I will also examine patterns of selection at MHC class II b by examining how individual genetic diversity at this locus corresponds to annual survivorship.

Supervisor: Dr. Hugh Henry
Degree: M.Sc. (Entrance Seminar)
Climate change may expose plants to greater stress in many northern temperate regions. Specifically, increasing air temperatures may expose plants to greater frost and drought stress. Cross-adaptation occurs when exposure to one stress increases tolerance to a second, different stress. Interestingly, both frost and drought result in cellular dehydration, and can stimulate the production of similar protective compounds. What I will investigate is how frost stress influences drought tolerance, and in turn how drought stress influences frost tolerance in Kentucky bluegrass (Poa pratensis). I will take an ecological perspective and assess tolerance by examining the effects on plant growth. Understanding the interactions between stresses may help us better predict how plants will respond to climate change.

Supervisor: Dr. Greg Thorn
Degree: Masters
The Agaricomycetes are a class of fungi that include most typical mushrooms. Tall grass prairies are an endangered ecosystem and there is great interest in studying their biodiversity and endeavoring to restore them. Little is known about Agaricomycetes in the prairies – what is out there, why it is there, and how to best uncover this. I will use both traditional and molecular techniques to analyze mushroom and soil samples from a variety of tall grass prairies to address these questions. My three objectives are: to characterize the Agaricomycetes of Ontario’s tall grass prairies, examine factors that may influence their composition (geography, soil, plants, and tillage history), and compare results of two different survey methods (aboveground mushroom collecting and belowground soil molecular analysis).

Degree: PhD

Understanding how animals recognize their kin has been a major challenge for psychologists and behavioural ecologists for decades. Two common mechanisms of kin recognition are familiarity and phenotype matching. When familiarity is used, individuals remember kin whereas when phenotype matching is used, individuals instead compare putative kin to a template of what kin should look (or smell) like. The guppy (Poecilia reticulata) has become an important model species in evolutionary biology. It has been shown that some populations of guppies use familiarity whereas other populations use phenotype matching. Capitalizing on this dichotomy, I will use breeding crosses to establish the inheritance patterns as well as search for the gene or genes underlying the different kin recognition mechanisms.

Supervisor: Dr. Charles Trick
Degree: Masters
Prymnesium parvum is a widespread golden algae species that inhabits marine, estuarine and inland systems. It is known to form harmful algal blooms that can have devastating effects on ecosystems and fisheries. This is due to the toxins produced by Prymnesium parvum that target the gills in fish and molluscs. These toxins cause hemolysis and produce reactive oxygen species that lead to the asphyxiation of the affected organism. In other algal species, iron is known to influence toxin production. However, the effect of iron on Prymnesium parvum toxicity remains unknown. For my project, I will be investigating the effects of limited iron availability on toxin production in Prymnesium parvum by conducting hemolytic assays, hydrogen peroxide assays and assays using a model gill cell line.

Supervisors: Jeremy McNeil & Ian Scott
Degree Sought: MSc. Biology
Generalist insect herbivores utilise visual, chemical and tactile cues to locate host plants. However, generalist soil-dwelling herbivores rely most on chemical cues in order to detect suitable and avoid unsuitable plants. Wireworms (Coleoptera: Elateridae) are generalists and are serious pests of many agricultural crops; thus requiring pest management strategies. Preliminary studies observed reduced wireworm densities (genus Agriotes) after buckwheat (Fagopyrum esculentum) is used as a cover crop; potentially due to the plant releasing repellent, antifeedant and/or toxic chemicals into the soil. I will explore the different potential effects of chemicals from buckwheat roots on wireworm behaviour, using a six arm olfactometer and small plot experiments.  My results will be the basis for subsequent chemical analyses, as these compounds could offer an alternate management strategy.

Supervisor: Dr. Greg Thorn
Common buckthorn (Rhamnus cathartica), a highly competitive Eurasian woody shrub, is currently invading North America.  Dense monoculture thickets of buckthorn reduce native plant species diversity and may also reduce diversity of soil organisms, including mycorrhizal fungi, negatively impacting surrounding symbiotic flora and facilitating invasional meltdowns. Manipulative garden experiments were done to assess the effects of root exudate, leaf litter and drupes, containing allelochemicals, on the diversity of naïve native arbuscular mycorrhizal fungi (AMF) associated with sugar maple (Acer saccharum) seedlings. Soil samples from sugar maple forests with and without buckthorn were surveyed for communities of soil fungi, including AMF.  Additionally, a comprehensive list of the local fungi occurring on buckthorn was generated in order to identify potential biocontrols.

Supervisor: Dr. Greg Thorn
Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with the roots of many vascular plants. AMF exchange soil nutrients from nutrient pools that the plants cannot reach themselves in exchange for photosynthetically fixed carbon. Arbuscular mycorrhizal fungi are an essential component of tallgrass prairie ecosystems. My project is looking at the effects of agricultural tillage on species composition of arbuscular mycorrhizal fungi in Ontario tallgrass prairies. The objectives of my project are to use Next Generation Sequencing to compare species composition of arbuscular mycorrhizal fungi in sites with different disturbance histories and determine if there are potential indicator taxa for the ends of the disturbance spectrum. Understanding how disturbance affects AMF could reveal information on how AMF can be used for restoration of endangered ecosystems.

The coordinated movements of groups arise by collective decisions between group members.  Black-capped chickadees have a stable dominance hierarchy in which dominants obtain more long and short-term gains (good breeding territories and food resources), than subordinates.  There is still some uncertainty to why subordinates join flocks at all.  Chickadees will be radio-tagged and tracked throughout the winter and breeding seasons for several years in order to examine how social rank influences flock structure as well as the interaction of social rank and breeding area size, survivorship, and caching and roosting behaviours.  I predict that subordinates achieve more fitness than previously thought, and that radio-telemetry methods combined with observational methods will reveal more details regarding social structure than would be possible with observation methods alone. 

Predator effects on prey populations extend beyond direct killing through changes in prey physiology and behaviour that can affect survival and reproduction. Under high predation risk, prey should reduce conspicuous behaviours, such as courtship and mating, in order to reduce their risk of detection. Although limiting their reproductive behaviours may increase their chances of survival, it may also reduce their reproductive success. Therefore, individuals must balance the risk of predation and their investment into reproduction. To test these ideas, I experimentally manipulated the risk of predation during the breeding season and sampled courtship and mating behaviour in both male and female brown-headed cowbird (Molothrus ater). Any potential changes can be used to infer how predation risk alone can impact prey populations by affecting reproductive success.

Degree: PhD (exit)
Supervisor(s): Scott Petrie/Jack Millar
The Eastern Population Sandhill Crane (Grus canadensis) was extirpated from Ontario within the last 100 years.  The species is of conservation and management concern to the provincial and federal government of Ontario and Canada, respectively.  Thus, managers required basic population biology data along with targeted management information to make informed decisions relating to the species.  In consult with the governments, we selected the primary autumn staging site for the species to collect data to address this void.  We estimated multi-year minimum population estimates, fall recruitment, migratory chronology, roost site selection, and feeding ecology using direct observation, GPS tracking, and field experimentation to address our management and research objectives.  Our results will inform wildlife managers as well as provide novel behavioural ecology data to the scientific community and beyond.

Supervisor: Graham Thompson
Degree: Masters
As social insects, termites typically live in kin-based colonies that are replete with sterile workers and soldiers. Despite their sterility, workers and soldiers can potentially gain indirect fitness by directing help towards reproducing relatives and defending against unrelated intruders. For invasive populations, however, these kin-mediated behaviors break down, leading to the formation of mixed-kin supercolonies that occupy vast areas. One potential explanation stems from the genetic consequence of the invasion itself; invasive populations go through a genetic bottleneck that strips them of alleles essential for recognition. If so, then invasive should have lower genetic diversity than non-invasive populations. In this study, I will use next-generation sequencing analysis to test this prediction on a genome-wide scale.

MSc Exit Seminar
The perceived risk of predation (i.e. the ‘fear’ of predators) can impact prey populations through behavioural and physiological changes that significantly affect survival.  Increased predation risk has been shown to induce body mass change in several bird species. Consequently, it is assumed these predator-induced changes in mass may affect an individual’s ability to evade predatory attack by altering flight performance (i.e. takeoff speed, ascent angle). By manipulating the level of predation risk in the environment, my research is specifically focused on how brown-headed cowbirds (Molothrus ater) respond physiologically to the increased risk of predation and aims to test the assumption that predator-induced mass change will affect various measures of flight performance.

Endurance flight during migration and immune system functioning are two very energetically costly activities for birds. Since nutritional resources are limited, there may be a trade off between migration and immune investment. Avian blood parasites consume host resources, which may further decrease a bird’s resource pool to the point where endurance flight and immune defense may not be possible simultaneously. I examine and compare naturally occurring levels of blood parasite infection in a migrating songbird population by microscopy and molecular methods. The prevalence and intensity of infection is compared to measures of immune defense, and the impact of infection intensity on endurance flight performance is assessed. Studying host-parasite interactions within the context of migration will help to improve knowledge of the ability of birds’ to migrate and spread disease over large geographic distances.

Supervisor: Dr. Greg Thorn
Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with the roots of many vascular plants. AMF exchange soil nutrients from nutrient pools that the plants cannot reach themselves in exchange for photosynthetically fixed carbon. Arbuscular mycorrhizal fungi are an essential component of tallgrass prairie ecosystems. My project is looking at the effects of agricultural tillage on species composition of arbuscular mycorrhizal fungi in Ontario tallgrass prairies. The objectives of my project are to use Next Generation Sequencing to compare species composition of arbuscular mycorrhizal fungi in sites with different disturbance histories and determine if there are potential indicator taxa for the ends of the disturbance spectrum. Understanding how disturbance affects AMF could reveal information on how AMF can be used for restoration of endangered ecosystems.

Supervisor: Brock Fenton
The echolocation calls that bats use to navigate their environment and find food can also play a social role. When nectar-feeding bats converge on a food source, they may rely on different calls to minimize the chances of mid-air collisions and interference by others. To explore this possibility, I conducted playback experiments with two species: Glossophaga soricina and Leptonycteris yerbabuenae. I predicted that these bats use echolocation calls and/or social calls to change flight behaviour and feeding approaches, or to effect ‘air traffic control’ while feeding. I investigated this by presenting a variety of playbacks to captive and wild bats and analysing behavioural responses and flight patterns. My research will improve our understanding of the role that these calls play during social interactions at feeding sites.

The production of androgens is hypothesized to have immunosuppressive effects in vertebrates. Here, I test this idea in bluegill sunfish, Lepomis macrochirus, by comparing the immune responses mounted by distinct male morphs in response to a vaccination. Sneaker males produce low levels of androgens and are thus expected to mount stronger immune responses than parental males, who produce relatively high levels of androgens during spawning.  Fish that were held in captivity following vaccination appear to have been highly stressed, so I have excluded their data from most of my analyses. Freshly caught fish of both male morphs demonstrate a positive relationship between their androgen production and white blood cell concentrations. I discuss these findings and their implications for the immunocompetence handicap hypothesis.    

Recent research has have begun to provide important insights into the origins and destinations of migratory bats, but fewer studies have examined how bats budget their time and energy en-route. Previous work in our lab found that during fall migration silver-haired bats (Lasionycteris noctivagans) use a torpor assisted migration strategy, which dramatically reduces daytime thermoregulatory costs, increases net refueling rate, and facilitates very brief stopovers. However, spring and fall migration pose different challenges. The concurrence of migration and pregnancy in the spring creates a conflict for female bats. Daily torpor use will spare energy stores for migratory flight, but may delay fetal development. Thus, sex may substantially affect the energy and time management of spring migrants in ways that wouldn’t occur during the fall. My research investigates sex differences in several aspects of spring migration ecology: arrival date phenology, body composition, stopover duration, torpor expression and migratory routes.  

Parasites are taxonomically and geographically widespread, and place important selective pressures on their hosts. Most studies exploring host-parasite coevolution have done so in the context of host species with predictable geographic ranges. Virtually nothing is known about host-parasite coevolution in hosts with nomadic distributions, such as red crossbills (Loxia curvirostra). Compared to most songbirds, marked vocal variation exists amoung red crossbill populations. Individuals with different vocal types also differ in feeding capabilities. In this study, I used genetic techniques to determine how haematozoan parasite communities differ among 4 ecologically and behaviourally isolated populations of nomadic songbirds. I screened 640 free-living red crossbills; 76 birds were found to be infected and sequences obtained were used to construct phylogenies of parasite lineages

Supervisors: Dr. Beth MacDougall-Shackleton & Dr. Scott MacDougall-Shackleton
Degree Sought: PhD

Animals which complete seasonal migrations are exposed to more than a single environment and parasite community. Due to the additional parasites, migrants may be expected to allocate relatively more resources to immune defense. Conversely, the high energetic cost of migration may constrain resources such that the immune response is compromised during migratory flight, suggesting diseased animals are less likely to migrate long distances. However, little is known about how birds cope with infectious disease while under the demands of migration despite being blamed, in part, for the long-distance transport of disease. My proposed research will investigate how migratory birds balance the demands of migration with the need to defend themselves against parasites by examining the plasticity of migratory traits in response to infection.

Supervisor: Jeremy McNeil

The majority of insect species that emigrate from deteriorating habitats do so as sexually immature individuals. A prolonged pre-oviposition period where resources are directed to flight machinery and fuel for migration could have a negative effect on subsequent reproductive output. Using the true armyworm, my study aims to address how flight and food quality affect the reproductive output of migrants and non-migrants with specific emphasis on natural rearing conditions.

Supervisor: Bryan Neff

The Pacific salmon have long been an ecological, economic and cultural foundation of communities in the Pacific Northwest of North America. Their viability is now threatened, however, as populations have been falling to historic lows over the past two decades. This loss prompted a judicial inquiry by the government of Canada in 2009 on the causes of decline, which found that changing marine conditions are likely responsible. Specifically, rising temperatures, reduced food availability, increased abundance of non-resident predatory fish and increased rates of sea lice infections interact to limit salmon during their coastal migration. In my proposed research, I will evaluate how the interaction of these stressors affects the aerobic capacity of migratory salmon using experimental and field-based approaches.     

No abstract.

Migration is an evolutionary adaptation employed by some insect species in the face of seasonally deteriorating habitat conditions. It is believed that there exists a physiological trade-off between reproduction and migration, and that the two states are incompatible.  Seasonal migrants often rely on environmental factors such as photoperiod, and temperature as indicators of deteriorating habitat. Differences in the onset of sexual development have been observed not only between migratory and non-migratory moth species but also between migratory (North American) and non-migratory (Azorean) populations of the same species (Pseudaletia unipuncta) reared under the same ecological conditions. My research compares and contrasts the behavioural, developmental, and morphological characteristics of the Hawaiian, Azorean (both non-migratory), and North American (migratory) armyworm under varying temperature and photoperiod conditions.

Supervisor: Dr. Amanda Moehring
Degree: PhD

Males and females often have differing reproductive strategies to increase their individual fitness.  The benefits of sexual selection can be acquired through mechanisms which can act on many levels: behavioural through female mate choice, or postmating through sperm competition and cryptic female choice.  The objectives of my research are to determine the traits that females select for in attractive males in Drosophila melanogaster and tease apart how attractive and unattractive males perform in both pre- and postmating sexual selection.  These different aspects of sexual selection at both pre- and postmating levels were examined to determine how they contribute to overall male mating success, providing insight into how populations evolve in response to sexual selection.   

MSc Exit Talk
Supervisor: Dr. Liana Zanette

Predator–prey interactions shape ecology, and reacting to a predator threat is crucial for survival. As many prey individuals survive predator attacks, it is important to recognize the lasting effects of perceived predation risk, from populations to individual neurobiology. We have a good understanding of the mammalian brain network that processes predator ‘fear’, but in birds this network remains largely unknown. I used auditory predator playbacks to simulate predator encounters in wild black-capped chickadees (Poecile atricapillus). Using immediate-early gene immunohistochemistry, I examined the short– and long–term effects of perceived predation risk in brain areas thought to be involved in the avian ‘fear’ network. My results demonstrate that perceived predation risk affects the brains of wild birds, and that these effects may persist following predator encounters

Predators affect prey populations beyond directly killing individuals. A growing body of research shows that the “fear” of being preyed upon (i.e. perceived risk of predation) can induce costly anti-predator behaviours that are powerful enough to reduce prey reproduction and survival. The majority of this research has dealt with the effects of fear on prey only during the nesting period, leaving the possibility that the total effect on populations is underestimated. My research examined how threat of predation effected the behaviour of Song Sparrows (Melospiza melodia) after the nesting period. To accomplish this we manipulated the threat of predation with predator playbacks. My results show that parents respond to predation threat. We are still assessing how if predation threat affects offspring behaviour as well.

Supervisor: Zoë Lindo
Nematodes are important environmental indicators, commonly used to assess soil quality following anthropogenic disturbance. This has led to the creation of a trait-based index – the Maturity Index – to determine soil state based on the nematode community. However, this method still relies on extensive knowledge of life history traits for these hyper-diverse animals. Since body size is a unifying trait, I proposed a novel use of body size spectra to show the same trends as the Maturity Index while overcoming taxonomic impediments. I qualitatively compared these metrics in a soil nematode community exposed to clear-cutting and three levels of wood-ash amendment in Chapleau, Ontario. There were no significant differences between these communities; however, body size spectra produced more information, with considerably lower time and expertise required.

MSc. candidate
Supervisor: Yolanda Morbey
Juvenile anadromous Pacific salmon make a drastic niche shift by migrating from their natal freshwater streams to the rich feeding grounds in the salty seas. To prepare them for this niche shift, they undergo complex behavioural, morphological, and physiological transformations collectively known as smoltification. My study investigated the time course of smoltification in underyearling Chinook salmon (Oncorhynchus tshawytscha) introduced into the adfluvial, or freshwater, environment of the Laurentian Great Lakes. I found that under natural photoperiod conditions in a hatchery setting, these fish undergo a normal course of smoltification. I also examined the degree to which body size affects the sensitivity of the photoperiod cues and I found evidence that during the peak smoltification window, individual body size does not seem to determine smolt status. This work is a foundation for the investigation of rapid adaptation of smoltification traits in Pacific salmon naturalized in adfluvial environments.

Climate change has increased the severity of winter storms. It is therefore important to understand the effects that inclement winter weather will have on species in future years. This study determined the effects that recurrent inclement winter weather has on white-throated sparrows (Zonotrichia albicollis). By use of a hypobaric climatic wind tunnel, I simulated winter storms by altering barometric pressure and temperature once per week for 9 weeks, and measured body composition and baseline corticosterone levels in birds exposed, or not exposed, to simulated storms. Recurrent weather cues caused an increase in fat, but had no effect on baseline corticosterone, suggesting these cues did not act as a chronic stressor. This novel research is a building block to determining how proposed environmental conditions will affect migrating songbirds.

Migration occurs in a small proportion of bat species. I monitored bats on two islands in the Great Lakes to identify migratory activity. Geographical barriers, such as the lakes, can concentrate migrating animals at favourable crossing routes. Looking for migration at such sites is an opportunity to learn about which species migrate and their mechanisms for doing so, as well as facilitating the protection of migrating animals throughout their entire ranges. For comparison, I also monitored bats at two mainland sites away from the lakes. I used automated recorders to capture ~4million calls, which I identified to species through automated analysis. I identified several species, notably Lasiurus borealis and Perimyotis subflavus, with higher activity during putative migration periods, and proportionally higher activity at island sites.

Is the frequency of algal blooms increasing in oligotrophic lakes in temperate forests?
Oligotrophic lakes in Ontario appear to be experiencing an increase in the frequency of algal blooms. This has been the focus of numerous public and government reports, resulting in heightened concern for algal blooms. We used remote sensing to: (1) develop regression models that relate Landsat imagery reflectance to chlorophyll-a (Chl-a); (2) apply these models to estimate Chl-a in lakes of the Algoma Highlands over a 28 year period (1984–2011). The linear regression model was built on the basis of the reflectance values acquired from Landsat imagery and in situ measurements. We applied this model to all lakes within the region for the peak algal bloom period for the entire 28 years. A time series revealed a cyclic stationary pattern in the average Chl-a. This pattern seems to follow the regional patterns of major droughts, making climate a major driver in the formation of algal biomass in lakes.

Supervisor: Graham Thompson
Degree: Masters of Science
Exploring the mechanisms by which individuals are able to assess group membership is fundamental towards understanding the evolution of altruistic care in eusocial insect societies. The eastern subterranean termite (Reticulitermes flavipes) is an introduced species in Ontario, living in large social groups comprised of workers, soldiers and reproductive members. To date, no studies have attempted to partition the relative influence of environment or genetic factors in the expression of recognition in R. flavipes. This study will aim to further understand nestmate discrimination in R. flavipes by determining the source of these cues in colonies of different genetic distances housed in one of two different environmental conditions. Overt agonistic responses between unrelated nestmates will be observed in behavior assays and used as measures of nestmate discrimination.

Supervisors: Dr. T. Gariepy and J. McNeil
Degree sought: PhD
Halyomorpha halys, Brown marmorated stink bug (BMSB), is an invasive pest from East Asia causing severe agricultural and nuisance problems. Reports of BMSB in USA (2001) and more recently in Canada (2012) have urged development of efficient control methods of this pest. Biological control of BMSB using egg parasitoids is promising, however the potential interaction of BMSB and parasitoids native to North America is unknown. Employing a combination of molecular and imaging techniques, the goals of my project are to: 1) determine which parasitoids are associated with BMSB in Canada; 2) determine native egg parasitoids’ ability to exploit BMSB as a host, as well as investigate potential differences in mechanism of parasitization of native and exotic parasitoids; and 3) investigate non-target effects of exotic parasitoids.

Co-Supervisors : Scott Petrie and Hugh Henry
Degree Sought : MSc
Much of the yearly variation in waterfowl survival occurs during the nesting and brood rearing period, where female and brood survival is strongly influenced by habitat selection. The wood duck is a cavity nesting waterfowl species that actively uses artificial nest boxes, which are a common management practice used across their breeding range. Therefore, the survival of females, and ducklings produced from nest boxes, is valuable information in determining local population dynamics and evaluating the efficacy of nest box programs. My research will improve our ecological understanding of wood duck brood rearing ecology at the northern range of the species, contribute to a broader understanding of the North American wood duck population, and help refine management practices for nest box programs and brood rearing habitats.

Supervisors: Anne Simon, Jeremy McNeil
Degree Sought : MSc
Alarm pheromones are chemical cues that warn conspecifics of potential danger and induce behavioural changes that reduce the probability of injury or death. In insects, alarm pheromones are generally released by both sexes, the induced response is directly proportional to the concentration emitted, and the infochemical dissipates rapidly. Drosophila melanogaster adults avoid areas previously occupied by stressed conspecifics in response to a Drosophila Stress Odor (dSO), suggesting this may serve as an alarm pheromone. Other than CO₂, the composition of dSO is unknown, but if it is composed of common compounds released in response to any form of stress then it should induce some level of response in Drosophila species that share similar habitats and/or natural enemies as D. melanogaster.

Supervisor: Dr. Scott Petrie/Dr. Christopher Guglielmo
Degree: MSc
Severity of weather necessary to cause southern migration by waterfowl may differ among species. Some species of duck may migrate independently of weather severity, where migration results from endogenous rhythms related to photoperiod. A Weather Severity Index (WSI) was previously developed for mallards (Anas platyrhynchos; Schummer et al. 2010) and used temperature and snow cover data to explain change in relative abundance of mallards at mid-latitude staging areas during autumn-winter. For my study, I am investigating the relative contribution of weather and photoperiod cues for other species of dabbling ducks. I obtained data from standardized waterfowl surveys conducted throughout eastern North America. Developed WSIs for each species of duck will be modeled with future climate change scenarios to determine how duck distributions may vary with climate change.

Supervisor: Bryan Neff
Climate change is projected to have widespread effects that could threaten the viability of natural populations. The ability of a species to adjust to climate change is modulated by its adaptive capacity, some of which involves an evolutionary response. Here we examine the adaptive capacity of Atlantic salmon, an important aquatic ectotherm. In the face of impending climate change, conservation managers may be faced with augmenting or reintroducing individuals that have high thermal tolerance or those from a population with high thermal tolerance. Indeed, current restoration efforts to produce a self-sustaining Atlantic salmon (Salmo salar) population in Lake Ontario focus on three source populations as candidates for reintroduction. In this study, we investigated underlying cellular and molecular factors that may facilitate tissue oxygen supply and thereby thermal tolerance at individual and family levels. The results of this study provide insight into long-term survival for ongoing restoration efforts of Atlantic salmon as well as more broadly into the thermal adaptive capacity of freshwater fishes.

Supervisor: Dr. Liana Zanette
Degree: MSc
Predator effects on prey populations extend beyond direct killing through changes in physiology and behaviour in response to predation risk that affect prey survival and reproduction. One aspect of this involves changes in courtship and mating behaviours which are conspicuous and increase the prey’s risk of detection by predators. As there is a survival cost associated with reproduction, individuals under predation risk should be expected to engage less in courtship and mating behaviours reducing their reproductive success in order to increase their survivability. I aim to examine the acute and chronic effects of predation risk on courtship and mating behaviour and reproductive success in brown-headed cowbirds (Molothrus ater) by experimentally manipulating predation risk during the breeding season.

Supervisor: Liana Zanette
It is becoming clear that the 'fear' of predators shapes prey ecology, in that the mere presence of a predator can leave lasting effects on prey physiology and reproduction. However, it is unknown whether perceived predation risk alters the avian brain and if there is a 'fear network' which processes predator cues. My goal is to examine behavioural and neurological changes in black-capped chickadees (Poecile atricapillus) in response to playbacks of predator calls and conspecific alarm calls. I will quantify activation in several brain areas using immediate-early gene immunohistochemistry and analyse behaviour in response to predator cues. I aim to better understand the processing of predator stimuli in the avian brain, whether neurobiological changes persist over the long term, and if behavioural changes also result.

Supervisor: Jeremy McNeil

Abstract: Because migratory and non-migratory populations occur within the same species, the true armyworm (Pseudaletia unipuncta) presents a unique opportunity to study the costs of flight on reproduction, and the adaptations that minimize such costs. It is believed that migrant populations establishing in a permanently usable habitat should eventually become non-migratory and thus develop traits investing more in reproduction than in flight.  Such a shift in life history has been observed in the Azorean (non-migratory) population of the true Armyworm. By comparing the Hawaiian (non-migratory) and North-American (migratory) Armyworm populations, I wish to test whether the findings in the Azorean population represent a general trend or an anomaly.

Supervisor: Scott Petrie

Animals often associate human disturbance equivocally to potential predation risk and have associated behavioural responses. In autumn and winter waterfowl are subjected to disturbance (i.e. hunting) which can have local effects on distribution and abundance. The juxtaposition of habitats of varying risk of mortality to waterfowl from hunting at Lake St. Clair, Ontario is ideal to investigate waterfowl movements and foraging strategies in relation to this anthropogenic disturbance. My research will estimate temporal and spatial variation of female mallard habitat selection in relation to potential risk of mortality from hunting. Additionally, I will assess how their habitat selection is subsequently related to their their survival and duration of stay within the region.

Supervisor: Liana Zanette
Predators have profound effects on prey population dynamics that go beyond simply killing prey.  The mere risk of predation elicits both behavioural and physiological changes that can alter prey survival.   Birds have been shown to make changes in physiological condition in response to a heightened risk of predation, which has been assumed to aid in increasing escape flight ability and thus evasion from predators.  My research examines whether brown-headed cowbirds (Molothrus ater) make strategic adjustments in order to improve their flight ability.  By manipulating the level of predation risk, I can examine the resulting effect on their physiological condition and test for any changes in flight ability

Doctoral Candidate
Supervisors: Nusha Keyghobadi, Brock Fenton

We expect parasites to be locally adapted to their hosts. We thus expect the parasite’s phylogeny and genetic structure, and the selection on its traits to be largely driven by its host. Insects in the Cimicidae family (Order: Hemiptera) are ectoparasites of warm-blooded animals, such as bats, birds and humans. There are evidences of host switching in many cimicid species in the genus Cimex between bats and humans. In my doctoral project, I will decipher genetic attributes of host associations to bats or humans in North American Cimex species. I will participate in the collection of samples from human homes and bat colonies throughout Canada. Then, I will analyze the collected samples to attempt to decipher differences between bat specialized and human specialized Cimex lineages.

Understanding whether parasites adapt to local hosts or if hosts adapt to local parasites has important implications for patterns of biodiversity. The objective of my research project is to determine the level of concordance between host red crossbill (Loxia curvirostra) population genetic structuring and that of their haematozoan parasites (genera Leucocytozoon, Haemoproteus and Plasmodium). By revealing the genetic structuring of host-parasite systems, my study will provide a better understanding of how host genetic diversity is influenced by parasites.

Supervisors: Scott A. MacDougall-Shackleton and David F. Sherry
Memory can have profound effects on reproductive success. Indeed, female brown-headed cowbirds (Molothrus ater) are obligate brood parasites and must remember the location of suitable host nests, unassisted by males, to ensure their young survive. Breeding females have a larger hippocampus than males. To examine whether females have more accurate spatial memory than males, we investigated sex differences in the memory of captive cowbirds using: 1) touchscreen and 2) spatial navigation tasks. Movement through the environment was important because females outperformed males on the spatial navigation task only. Spatial memory is adaptively specialized in females for brood parasitism. We are currently examining sex, seasonal, and species differences in hippocampal volume, neuron density, and neurogenesis to provide a strong analysis of specialized brain plasticity.

Supervisor: Beth MacDougall-Shackleton

A compelling candidate gene at which both good-gene and compatible-gene effects on fitness may occur is the major histocompatibility complex (Mhc). Mhc loci play a key role in vertebrate immunity through recognizing non-self peptides and presenting them to T-cells. A greater number of distinct Mhc alleles produce a wider array of antigen-binding proteins. In songbirds, it has been proposed that although assessing the genetic similarity (including Mhc profile) of a potential mate might well be adaptive, it may nonetheless not be possible. I will assess potential methods of communication (i.e. song and olfaction) in song sparrows and see if they relay information of Mhc genotype to the receiver.

PhD Candidate
Supervisor: Kathrin S. Bolstad; J. Mark Hanson. Visiting student from New Zealand, hosted by Louise Milligan

Deep-sea squids of the family Octopoteuthidae have been collected from every ocean except the Arctic, and are an ecologically important group, being both key prey for apex marine predators as well as active predators themselves. However, these squids remain poorly studied due to the taxonomic disarray of the family. To rectify this, a global systematic revision is being undertaken based primarily on morphology, but with support, when available, from molecular techniques. Observations to date suggest the existence of ten octopoteuthid species worldwide, including at least three previously undescribed, distributed between two genera. The considerable size of these undescribed species (> 20 kg, > 50 cm body length) demonstrates the continuing poor state of knowledge on the deep ocean, its inhabitants, and their interactions.

MSc candidate
Supervisor: Bryan Neff

Salmon populations have been steadily decreasing across both the eastern and western coast of North America. There have been recent efforts to reverse these declines through hatchery release programs. Unfortunately, many of these programs have been unsuccessful in reversing population declines. Mortality in juveniles caused by inappropriate responding to predator threats may have an effect on hatchery release programs. Predator recognition is a critical aspect of anti-predator behaviour that is potentially altered by hatchery rearing, due to a lack of exposure to predator cues. I will investigate predator recognition in juvenile Atlantic salmon (salmo salar) across three populations with different captive breeding histories. Understanding differences in predator recognition across these populations will shed light on the effect of captive breeding on anti-predator behaviour.

MSc Candidate
Supervisor: Bryan Neff

Nectar-feeding bats play a crucial role in their environment as pollinators and seed dispersers, but little is known about their social interactions at feeding sites. Knowledge of the group dynamics of bats improves our ability to allocate sufficient land and resources for their conservation. In high traffic feeding areas, communication is essential for preventing collisions and maintaining an effective feeding system. This project will investigate the social implications of echolocation in three species of nectar-feeding bats: Glossophaga soricina, Leptonycteris curasoae and Choeronycteris mexicana. I will explore the interactions among these bats visiting point sources of food, using playback experiments and flight-path analysis, and analyze the responses to different echolocation playbacks in order to determine the social context of these calls.

MSc. Candidate
Supervisor: Greg Thorn

Arbuscular mycorrhizae are important symbiotic associations between arbuscular mycorrhizal fungi (AMF) and the roots of many vascular plants. AMF exchange soil nutrients (such as phosphorus) from nutrient pools that the plants cannot reach themselves in exchange for photosynthetically fixed carbon. Arbuscular mycorrhizae are favoured in grassland ecosystems like Walpole Island. Currently, restoration attempts at Walpole are underway to restore agriculturally disturbed fields back to natural tallgrass prairie. A consequence of agricultural disturbance is the simplification of plant communities and disruption of the mycelial networks of AMF. I will be using Next Generation sequencing to determine the species composition of AMF in areas with different disturbance histories. Understanding how disturbance affects AMF could reveal information on how AMF can be used for restoration of endangered ecosystems.

Supervisor: Liana Zanette
Degree: MSc

Predators effect prey populations beyond directly killing individuals. A growing body of research shows that the “fear” of being preyed upon (i.e. perceived predation risk) can induce costly anti-predator behaviours that are powerful enough to reduce prey reproduction and survival. The majority of this research has dealt with the effects of fear on prey only during the nesting period, but the effect on prey beyond this period is as yet unexplored. I will study how acute threat of predation effects the behaviour of Song Sparrows (Melospiza melodia) after the nesting period. To accomplish this I will manipulate the perceived threat of predation with predator playbacks. During the playback I will record the behaviour of both parents and young and compare to behaviour during control periods.

MSc. candidate
Supervisor: Irena Creed
For decades, cyanobacterial harmful algal blooms (cyanoHABs) have been observed frequently in eutrophic, nutrient-rich lake systems. Surprisingly, cyanoHABs have been reported in nutrient poor, oligotrophic waters in recent years. Despite nitrogen and phosphorous as important components in the production of cyanobacterial blooms, another way cyanobacteria can assimilate nutrients is by utilizing siderophores to competitively bind iron. In this laboratory grow-out experiment, it is hypothesized that cyanobacterial hydroxamate and catecholate siderophore production will be heightened when phosphorous and nitrogen are low in induced Fe-limited conditions. Filtered lake water and natural phytoplankton obtained from study sites will be used to emulate real-world conditions, and the experimental manipulations will improve our mechanistic understanding of what is controlling the expansion of cyano HABs in freshwater systems.

MSc Candidate
Supervisor: Dr RG Thorn
Common buckthorn (Rhamnus cathartica), a highly competitive Eurasian woody shrub, is currently invading North America.  Dense monoculture thickets of buckthorn reduce native plant species diversity and may also reduce diversity of soil organisms, including mycorrhizal fungi, negatively impacting surrounding symbiotic flora and facilitating invasional meltdowns.  Current long-term control methods including cutting, physical removal or herbicidal applications, exhaust resources. I will be surveying forested regions in Middlesex County, Ontario, identifying fungi associated with the leaves, bark, and roots of Rhamnus cathartica to identify potential biological controls. I will also perform manipulative experiments to assess the effects of root exudate, leaf litter and drupes, containing allelochemicals, on fungal diversity in previously uninvaded soils and on diversity of arbuscular mycorrhizal fungi associated with sugar maple (Acer saccharum) seedlings.

Supervisore: Dr. Nusha Keyghobadi
Degree being sought: M.Sc Candidate

The Rocky Mountain apollo butterfly is an ideal subject to study spatially-structured populations, dispersal, and gene flow because of its patchy distribution in mountain landscapes. Sudden, severe reductions in population size (i.e., ‘collapse) are becoming more common in this species with unfavorable over-wintering conditions resulting from climate change, and could cause a loss of genetic diversity through random drift. Using long-term demographic data and samples collected over several years, I will assess the complex interaction between landscape structure, demographic fluctuations and genetic diversity. I will describe the population genetic response to repeated demographic collapses by genotyping samples collected before and after collapses. I will also quantify the time lag between changes in spatial genetic structure and changes in underlying rates of movement.

Supervisor: Dr. Yolanda Morbey
Degree: M.Sc Candidate

Fish growth can influence maturation timing, with fast growers maturing at a younger age. Furthermore, a different age at maturity can lead to the adoption of alternative reproductive tactics, such as delayed spawning in younger breeding female salmon. The goal of my project is to understand to what degree growth influences the expression of different reproductive tactics in female Kokanee Salmon (Oncorhynchus nerka). Females return to spawn with either a silver colour or a common red nuptial colour. Silver females were generally younger and smaller than the red ones. To compare the growth rate between two phenotypes, I will reconstruct the fish body size at an early age with an established otolith model

PhD candidate
Supervisor: Christopher G. Guglielmo
Joint-Supervisor: Brian A. Branfireun

Mercury is a global threat to human and environmental health. Anthropogenic emissions of mercury have doubled over the past two centuries. Recent research found that songbirds which feed primary invertebrates often accumulate at ppm level, which can cause negative effects in bird fitness. Many migrants can exposure to mercury on their breeding/wintering grounds, as well as migrating routes. How mercury affect bird migration and over winter is still un-known. I will be looking for what is the mercury level during migration: How mercury affect avian migrating distance? Do birds with higher Hg burden face lower survival rate over wintering period and migrating ability affected by mercury in the wind tunnel as well. Hopefully my study will give insight into mercury effects on songbird migration.

Supervisor: Chris Guglielmo

Endurance flight during migration is an energetically demanding activity for birds to perform. As a result, birds may be faced with trade-offs between migration and other energetically costly processes, such as immune system functioning.  Avian blood parasites consume host resources and diminish the oxygen carrying capacity of blood. This may decrease a bird’s resource pool to the point where both endurance flight and immune defense cannot occur simultaneously, as well as limit the ability of birds to perform strenuous exercise. Using parasite counts, genetic analyses, and measures of immune system functioning, I will examine the naturally occurring levels of blood parasite infection and immune system functioning within a migrating population of yellow-rumped warblers (Setophaga coronata). I will then assess the impact of infection on endurance flight performance and immune system functioning within the laboratory.

Supervisor: Scott MacDougall-Shackleton
M.Sc Candidate

Climate change is affecting an increasing number of natural systems and populations across the globe. Along with rises in temperature and precipitation levels, climate change has also been linked to increasing the latency and severity of storms at nearly all latitudes. Such storms are creating difficult environmental conditions for many species, including birds. I will be studying the long-term stress and behavioural effects that inclement winter weather has on a migrating species, white-throated sparrows (Zonotrichia albicollis). To achieve such results, I will be using a hypobaric climatic wind tunnel to simulate high and low pressure systems which affects temperature and barometric pressure accordingly. The stress and behavioural responses will give an insight into how a migrating songbird is responding to human induced climate change.

Supervisor: Dr. Edward Topp
Co-supervisor: Dr. Hugh Henry
Degree: M.Sc. Candidate

Soil organisms are an important part of nutrient cycling, converting organic material into nitrate forms accessible to plants. With the increased antibiotic use in farm animals to prevent sickness and increase productivity, increasing amounts of antibiotics and their metabolites are reaching the agricultural fields through animal waste used as manure. Many of these drugs are persistent in the environment and can have negative effects on soil organisms. In this project I looked at the effects of three antibiotics. I examined their persistence in soil, their effects on nutrient cycling (mineralization and nitrification), and abundance of ammonia-oxidizing microorganisms (bacteria and archaea that convert ammonia into nitrate). I will present results on mineralization in soils under different drug treatments.

Supervisor: Dr. Bryan Neff
Degree: Ph.D. Candidate
A major challenge in restoring native biodiversity is restoring extirpated populations. Candidate populations for reintroduction can be selected based on the classic concept of genetic matching (genetic connectivity) and the emerging concept of environment matching (similar environments). Here, I examined the performance of three candidate populations of Atlantic salmon (Salmo salar) being considered for reintroduction into Lake Ontario: Saint-Jean (genetic match), Sebago (environment match), and LaHave (neither a genetic nor environment match). Juvenile salmon were exposed to competition with juvenile non-native salmonids, a known impediment to restoration in Lake Ontario. Sebago salmon appear to have better performance than the other two populations examined, suggesting that there are merits to considering candidate populations that are environment matches to the altered environments of extirpated populations.

Supervisor: Dr. Zoë Lindo
Degree: M.Sc (Biology)
Microinvertebrates are a ubiquitous component of almost all terrestrial soil communities. They play a major role in decomposition, stimulate microbial activity, and contribute to soil formation and turnover. However, the enormous amount of undiscovered diversity among soil fauna and the difficulty of directly observing their activities means new methods must be developed to better understand how these organisms will respond to anthropogenic environmental change and what implications this may have for terrestrial systems. My research applies metrics of community composition and function based on trait and body size distributions and compares these to classic taxonomic species identity approaches. I have used these methods in lab and field experiments to determine the combined and individual effects of environmental variables and nutrient availability on soil microinvertebrate community composition.

Supervisor: Dr. Beth MacDougall-Shackleton
Degree: M.Sc. Candidate

Parasites are a widespread and diverse group that can significantly impact host survivorship and reproductive success. The more heterogeneous the environment an organism encounters, the more likely it is to encounter a wider variety of parasites; if a bird moves to a new population, it must cope with infection by new and foreign parasites. Previously in my studied song sparrow population, birds of local natal origin were found to have lower parasite loads than non-local birds. Local adaptation and coevolution have been suggested as mechanisms explaining this, but I examine an alternative: varied immunocompetence.  I use assignment tests to determine whether birds of this population are of local natal origin and I relate this to parasite loads and to several measures of immune function.

Supervisor: Dr. Hugh Henry
Degree: M.Sc. Candidate

Oaks were historically dominant canopy trees in many North American ecosystems. Failure to sufficiently regenerate over the past century has left most oak populations in steep decline. This phenomenon is known as “oak recruitment failure”. The Quercus genus is a larval host to 534 Lepidoptera species, more than any genus on this continent. The insect biomass produced on oaks is critical food for many songbirds. I will be studying the mechanisms by which non-indigenous creeping red fescue (Festuca rubra var. commutata) limits oak recruitment in old field ecosystems. These mechanisms are still unclear and proposed factors include herbivore overpopulation, competition, and missing ectomychorrhizal associations. My research will specifically test if creeping red fescue releases allelopathic phytochemicals that suppress acorn germination and subsequent seedling survival.

Supervisors: Dr. Beth MacDougall-Shackleton and Dr. Scott MacDougall-Shackleton
Degree: M.Sc. Candidate

Life-history theory predicts animals face trade-offs with immune defence while performing strenuous exercise, such as migratory flight. Long and short-distance migrants differ in the parasites they encounter where short distance-migrants re-encounter the same pathogens throughout their lifetime while long-distance migrants encounter a much larger set of parasite fauna. I hypothesize that song sparrows of a partially migrant population should strategically allocate immune function in relation to their migratory strategy and, thus, parasite fauna. Using stable isotope analysis and a variety of immune techniques my results show that, overall, long distance migrants had weaker immune responses than short-distance migrants. Additionally, upon arrival to breeding grounds birds shifted their immunity from innate to adaptive. This demonstrates the high energetic cost of migration and plasticity of immune allocation.

Supervisor: Dr. Scott MacDougall-Shackleton
Degree: Ph.D. Candidate

Birdsong is a sexually selected trait that influences female mating preferences and male-male competition. Features of male song production correlate to measures of male condition and fitness suggesting that song is an honest indicator of male quality. One problem with this theory is that it has been difficult to determine the costs associated with certain song attributes, such as song complexity. The Developmental Stress Hypothesis proposes that the honesty of birdsong is maintained by costs incurred during development, such that song in adulthood reflects exposure to early-life stressors. I provide support for this hypothesis by showing that exposure to early-life stress affects: 1) adult phenotypic quality, 2) adult male song production, and 3) development of a brain region involved in song learning and production.

Supervisor: Dr. Greg Thorn
Degree: Ph.D. Candidate

Peatlands have an important role in global climate change through sequestration of atmospheric CO₂, but there is concern that altered fungal community function may turn peatlands from carbon sinks to carbon sources, greatly exacerbating the impacts of climate change. In an experiment established in °ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â's Biotron facility, I will assess the impacts of the elevated temperature, carbon dioxide concentration and altered hydrology associated with Canada's predicted climate change on communities of fungi in intact peat cores. Community genomic DNA will be extracted from peat samples from cores in each experimental treatment and fungal communities will be assessed by next-generation sequencing of a portion of ribosomal DNA.  Changes in fungal communities will be related to changes in nutrient cycling and release, vegetation, and peat microfauna.

Supervisor: Dr. Irena Creed
Degree: M.Sc. Candidate

Lakes in North America have experienced an increase in the frequency of cyanobacterial blooms over the last 15 years. While cyanoblooms were the bane of water quality issues in the 1970’s, restrictions in the release of phosphate into surface waters virtually eliminated them. In my project I consider a new model aimed at explaining why some lakes in Ontario experience new cyanoblooms, in spite of phosphate release restrictions. I hypothesize that the reasons for this are climate-driven changes in lake’s contributing catchments that cause alterations in nutrient discharge. I evaluate the effect of the nutrient contribution to the phytoplankton biomass and the cyanobacterial presence, normalizing the lakes for their shapes and sizes using digital bathymetry data. This is the first study to compare the importance of catchment controls on nutrient dynamics in lakes coupled to the effect of lake morphometry on increasing risk of cyanoblooms.

Supervisor: Dr. Bryan Neff
Degree: M.Sc. Candidate

The immunocompetence handicap hypothesis posits that androgens such as testosterone and 11-ketotestosterone have an immunosuppressive effect. This enables androgens and their associated behaviors to function as honest signals of fitness, as only males with the best genes for immune defense can afford the immunosuppression caused by these hormones. Alternate male life histories have been documented in Bluegill Sunfish (Lepomis macrochirus). Parental males have high androgen levels, and must use aggressive behaviours to defend their nests from intruders. Sneaker and satellite males have low androgen levels and steal fertilization events from parental males. The life histories are thus expected to differ in their response to an experimental immune system challenge, due to differing levels of androgen production. Understanding how reproductive hormones affect immunity is critical, as concentrations of endocrine disrupting compounds continue to increase in aquatic environments worldwide.

Supervisor: Dr. Phil Taylor
Co-supervisor: Dr. Christopher Guglielmo
Degree: Ph.D. Candidate

Counts of migrating animals are often used for long-term population monitoring and for the assessment of Species At Risk.  However, the use migration counts for this purpose relies on several assumptions, including that individuals counted depart the count site within 24 hours; that factors that influence counts, including effort, habitat, and stopover duration, do not vary systematically over time; and that detected fluctuations in population size are proportional to fluctuations in the underlying larger-scale populations. Using simulated counts of migrating birds, I examine how sampling intensity and stopover duration influence our ability to reliably estimate population change.  I also assess whether regional and national population trends can be detected with sufficient power to inform conservation efforts, given realistic levels of daily and annual variability in counts at and among migration count sites.

Supervisor: Dr. George Lazarovits
Co-supervisor: Dr. Greg Thorn
Degree: M.Sc. Candidate

Potato common scab is a tuber- or soil-borne disease caused by several species of Streptomyces. Once established in the soil these bacteria can survive for years making it difficult to eradicate. However, recent studies showed that suppressiveness against common scab can develop naturally due to the presence of antagonistic micro-organisms such as Pseudomonas species. The objective of this study is to reduce or eliminate the number of pathogenic Streptomyces found on the potato surface to reduce or eliminate transmission of common scab to non-infested soils. Preliminary results showed statistically significant decline in the number of pathogenic Streptomyces per gram of tissue on the mother tuber. In the field trial, seed treatments showed statistically significant differences in yield but not in scab incidence between different cultivars.

Supervisor: Dr. Scott Petrie
Co-supervisor: Dr. Hugh Henry

Waterfowl exploitation of agricultural forage has triggered population increases and changes in migration routes and timing of migration. Because changes in habitat availability and foraging profitability have the potential to greatly influence the population dynamics of waterfowl, understanding temporal and geographic selection of these habitats is necessary to manage resource availability for waterfowl. The purpose of my research was to identify these selection relationships and to further understand the mechanisms driving them. Results indicate wetlands were used equal to availability during migration, but were not selected during winter when Tundra Swans selected open water and agricultural habitats. Open water was the most strongly selected habitat during migration and seasonal comparison of migration indicated a 2-fold increase in use of agriculture from autumn to spring. My results have contributed to scientific understanding of avian migration and wintering ecology and will help guide management of Arctic-nesting waterfowl throughout the nonbreeding period.

Supervisor: Dr. Scott Petrie
Co-supervisor: Dr. Irena Creed
Degree: M.Sc. Candidate

Weather affects timing of spring migration in birds but how exogenous factors influence timing and rate of migration by lesser scaup to their breeding grounds is relatively unknown.  I used locations of scaup tracked by satellite telemetry, waterfowl surveys of scaup and mallards, and corresponding weather data to evaluate competing models to explain variation in timing and rate of migration by scaup.  Timing of spring migration varied negatively with factors influencing energetic costs (spring mean temperature) and positively with those affecting habitat availability (rainfall and snow water equivalence). Difference in date of peak migration by scaup and mallards through North Dakota was not explained by exogenous factors.  My analyses suggest flexibility in timing and rate of spring migration by lesser scaup based on exogenous factors.

Supervisor: Dr. Brock Fenton
Co-supervisor: Dr. Jeremy McNeil
Degree: M.Sc. Candidate

Flight allows bats to migrate over relatively large distances, in order to follow food resources and favorable weather climate. Large numbers of North American migrate through the region of the Great Lakes, which can provide a significant physical barrier. I am investigating the importance of two Great Lake islands, Amherst and Pelee. I am collecting data using acoustic data from remote bat detectors, and will analyse this to identify species, look for annual patterns in activity, and compare to activity at other sites. If the islands prove to be significant sites for migrating bats, this could make them a priority for conservation, as degradation at such sites could have a disproportionate effect of the wider population.

Supervisor: Dr. Zoë Lindo
Degree: M.Sc. Candidate

The use of wood ash as a soil amendment is a popular practice in Scandinavian silviculture but still being assessed in Canada. Effects of wood ash on soil communities are not fully understood including its effects on soil animal communities. Nematodes are ubiquitous in soils, representing a major link in soil energy pathways between microflora and larger animals. This project investigates the effects of wood ash on free-living nematode communities in a forestry stand near Chapleau, Ontario. Traditional measures of community composition (richness, abundance), as well as the nematode-specific Maturity Index will be compared to a novel application of Body Size Spectra – a measure of community composition based on organism size instead of identity. This project is a first-step in the assessment of wood ash effects on nematode communities in Canada and demonstrates the potential for Body Size Spectra as a standard soil community measure.

Supervisor: Dr. Nusha Keyghobadi
Degree: M.Sc. Candidate

Communities and populations that occupy container-like habitats, such as the northern purple pitcher plant, Sarracenia purpurea, are ideal for addressing questions in spatial ecology and landscape genetics due to the occurrence of multiple species within spatially well defined habitat patches. The northern purple pitcher plant is the exclusive larval habitat for the flesh fly, Fletcherimyia fletcheri. I examined the effects of broad scale landscape configuration and composition on the population genetic structure of this flesh fly in 15 discrete habitat patches across Algonquin Provincial Park. Through the use of spatially referenced genetic samples I developed a model to test hypotheses about rates of gene flow and movement through the landscape, based on least cost pathway analysis.

Supervisor: Dr. Brock Fenton
Degree: M.Sc. Biology

Flower-visiting bats are an important pollinator group but 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 collected dietary data from guano and used acoustic monitoring to assess bat activity at flowers. I found evidence of partitioning of plant resources among the bat species, although evidence of limiting resources was not observed. Morphological similarity between species did not predict dietary overlap. However, species differing in their morphological specialization for nectarivory consumed resources and visited flowers at different frequencies.

Supervisor: Dr. Yolanda Morbey
Degree: M.Sc. Candidate

Salmonid fishes are excellent systems for studying the phenomenon of rapid adaptation following introduction into novel environments. The Great Lakes have been stocked with Pacific salmon for a century and many naturalized populations have established. These populations present an opportunity to investigate adaptations of preparatory smoltification traits in c. 12 generations. Smoltification is a complex transformation – morphological, behavioural and physiological – preparing juvenile salmon for their outmigration to the marine environment. Because juveniles of the introduced populations now migrate into the lake rather than the ocean, the physiological preparations for salt water are no longer necessary. I will test for adaptation in smoltification traits by comparing juveniles from a naturalized Great Lakes population with those from the ancestral population, raised in a common garden.

Supervisor: Dr. Graham Thompson
Degree: Ph.D. Candidate

For social insects, there are two levels of immune defense. Individual immunity consists of a conserved innate response involving the expression of antimicrobials upon infection. Social immunity, by contrast, is a derived phenomenon specific to social animals whereby individuals cooperate to reduce each other’s pathogen load. Using the Eastern subterranean termite as a model, I studied the ability of termites to mount a social immune response. First, I show that group-level behaviours do confer social immunity in the face of infection, and that this immunity is dependent, not on the number, but on the nature of social interactions. Second, I use molecular techniques to identify several termite immune genes, and show their expression to vary as a function of social context.

Supervisor: Dr. Hugh Henry
Degree: Ph.D. Candidate

Field experiments are commonly used to investigating potential ecosystem consequences of climate warming and nitrogen deposition, yet the lack of experimental control relative to laboratory-based investigations may present influential artifacts. For instance, herbivores may concentrate feeding to plots offering beneficial microhabitat or high quality resources. For this study exclosures were employed to explore interactions of herbivory with warming and nitrogen addition manipulations. Exclusion of rodents from nitrogen plots resulted in significantly greater biomass than did their exclusion from non-fertilized plots. Likewise, mollusc exclusion from warmed plots resulted in significantly greater biomass than did their exclusion for ambient temperate plots. Overall, these results suggest quantification of plant responses in global change field experiments may be substantially influenced by species-specific herbivore sensitivities to warming and nitrogen addition.

Supervisor: Dr. Chris G. Guglielmo
Degree: Ph.D. Candidate

Young songbirds make their first migration when they are only a few months old and tend to do less well compared with adults in several measures of migratory performance, including length of stopover. Underlying physiological factors, such as energy expenditure and digestive efficiency, may contribute to longer stopover durations of juveniles. For juvenile and adult songbirds during fall migration, I measured body compositions using quantitative magnetic resonance and dissection, basal metabolic rates using open-flow respirometry, and digestive efficiencies using total collection feeding trials. Juveniles tended to have larger digestive organs and higher metabolic rates, but equivalent digestive efficiencies. These results suggest that juveniles are physiologically different than adults during fall migration, and that these differences provide greater challenges to juveniles during their first migration.

Supervisor: Dr. Hugh Henry
Degree: Ph.D. Candidate

In northern temperate regions, climate warming is predicted to decrease the proportion of precipitation that falls as snow. Reduced snow cover can increase soil freezing, causing microbial lysis, disruption of soil aggregates, and damage to roots, ultimately leading to decreased ecosystem nitrogen retention. Coupled with increased atmospheric nitrogen deposition and ecosystem nitrogen saturation over the next century, nitrogen losses may be exacerbated. The objective of my study was to investigate the interactive effects of soil freezing and nitrogen deposition on nitrogen retention in a temperate ecosystem. My results indicate that soil freezing can enhance winter ecosystem nitrogen losses, and also lead to decreased retention of nitrogen deposition during the summer. My findings highlight the likely importance of winter climate change in modifying ecosystem nitrogen retention.

Supervisor: Dr. Graham Thompson
Degree: M.Sc. Candidate

Kin selection explains how social behaviour can evolve at the gene level, but it does not identify which genes are necessary for the expression of altruism. Using microarray data, we reconstructed ten provisional knowledge-based gene networks that describe altruism by means of ovary activation and de-activation in the honey bee. Nine out of ten networks were enriched for Gene Ontology terms pertaining to reproduction, and the hub genes of each network consist of either transcription factors, signaling genes, or genes involved in oogenesis. The relatively low (17%) gene overlap among networks suggests bees are using different suites of genes throughout their behavioural ontogeny to regulate ovary activation, and taken together these networks provide the first insights of the molecular interactions necessary for reproductive altruism.

Supervisor: Dr. Beth MacDougall-Shackleton
Degree: M.Sc. Candidate

Birdsong, like many mating signals, has multiple aspects to which receivers can attend. One such aspect is vocal performance, defined as the ability to perform physically demanding song. My project aimed to determine the best way to measure vocal performance in birds with complex song such as the song sparrow (Melospiza melodia), and to examine relationships between performance, morphological constraints, and other song characteristics. I found that distinguishing between simple and complex trills, and measuring maximum performance is the most effective measure of vocal performance. Bill size does not constrain performance, however vocal performance is positively correlated with a bird’s song repertoire size, a known proxy for male quality. This suggests that vocal performance may also encode important information for the receiver about male quality.

Supervisor: Dr. Jeremy McNeil
Degree: M.Sc. Candidate

The western bean cutworm (WBC), an insect pest of corn and dry beans, has recently expanded its range eastward reaching Ontario and Quebec provinces. Since environmental conditions can affect patterns of release from artificial lures in pheromone traps (used in pest management programs) and from feral insect females, this project aims to investigate the calling behaviour and sex pheromone synthesis of WBC female moths under different abiotic (temperature and relative humidity) and biotic (age and mating status) conditions. I will present results on age of female sexual maturation, and patterns of calling behaviour in virgin females held under different abiotic and biotic conditions.

Supervisor: Dr. Yolanda Morbey
Degree: M.Sc. Candidate

Different reproductive phenotypes occur in female kokanee salmon (Oncorhynchus nerka) returning in the fall spawning season to Meadow Creek, British Columbia. Female kokanees either arrive in the creek with a changed red skin color, which is most common, or as others that maintain their silver colour. Red- and silver-arriving females differ in age and size at maturity with the silver females younger and smaller than the red ones. During the life history of a fish, growth is one of the characteristics whichplay a significant role in decision-making of age and size at maturity. Theoretically,rapid growing fish tend to mature younger to decrease pre-maturation mortality risk, while the slow growing fish prefer delayed maturation with increased fecundity. The aim of my project is to use otolith growth as a proxy to compare fish growth in different life stages between two phenotypes, thereby investigating to what degree growth influences the difference in age and size at maturity of female kokanee salmon.

Supervisor: Dr. Yolanda Morbey
Degree: M.Sc. Candidate

Chinook salmon (Oncorhynchus tshawytscha) were first introduced to the Great Lakes in the late 1960’s with embryos from the Green River, Washington. Since then, they have colonized tributaries throughout the Great Lakes. In salmonid fishes, egg size is known to be locally adapted and capable of rapid evolution in novel environments. The purpose of my research is to test for the adaptation of egg size in Great Lakes Chinook salmon populations. I first tested for differences in egg size among populations after controlling for the effect of female size. Egg size differed among populations with 20% and 23% of the variance explained by female size and among population differences respectively. I also found that egg size accounts for much of the variance in early growth.

Supervisor: Dr. Jeremy McNeil
Degree: M.Sc. Candidate

Pheromone traps are often an important component of IPM programs. However, as with the western bean cutworm (WBC), Striacosta albicosta in the Great Lakes region, trap catches are not good indicators of subsequent infestations. In part, this is because we do not have good data on the influence of abiotic factors on either the emission of, or response to, pheromones. I will present the results of a two-year field study examining the effects of temperature, wind speed and relative humidity on the number of WBC males captured in pheromone traps.

Supervisor: Dr. Scott Petrie
Co-supervisor: Dr. Chris Guglielmo
Degree: M.Sc. Candidate

Shortly after the introduction of Dreissenid mussels to the lower Great Lakes in the mid-1980s, the abundance of diving and sea ducks increased rapidly during winter. An increase in food combined with warmer winter temperatures and decreased ice cover may be contributing to the increased abundance of overwintering Long-tailed ducks at Lake Ontario. Plans to develop offshore areas with industrial wind turbines may influence habitat use by Long-tailed Ducks. Preliminary results suggest that habitats are used offshore nocturnally for roosting and nearshore diurnally where they select areas to forage in shallower water with a greater abundance of macroinvertebrates. My goal is to develop relative probabilities of habitat use across Lake Ontario to determine areas where offshore industrial wind turbines would interfere with foraging and roosting.

Supervisors: Dr. Brock Fenton and Dr. Fred Longstaffe
Degree: M.Sc. Candidate

Stable isotope analysis has become an important tool for studying bat ecology. Stable hydrogen isotopic compositions from fur (δ ²H _fur) are particularly useful for determining the extent and occurrence of migration in bats. Little is known, however, about the effect of trophic level on δ ²H _fur values. Understanding the effect of trophic level on δ ²H _fur variation can help us refine our understanding of migration in bats as well as provide information about their diets. I will conduct stable isotope analyses on several bat species, both captive and wild, to determine if there is an effect of trophic level on the stable hydrogen isotopic composition of bat fur.

Supervisor: Dr. Brian Branfireun
Degree: M.Sc. Candidate

Long-term monitoring has revealed a recent increasing trend in mercury (Hg) levels in the top predatory fish of Lake Erie, despite the decline in regional atmospheric Hg emissions. This project explores the roles that recently introduced invaders, such as the round goby and dreissenid mussels, play in the transfer of Hg and its methylated form (MeHg) throughout the lake-wide food web. Results show that aqueous total and methyl Hg levels are low, often beneath EPA and instrument detection levels. Measured Hg concentrations in goby, yellow perch and walleye corresponded with literature values, indicating an inter-basin difference from West to East. Future work aims to analyze findings with the perspective of trophic transfer from lower foodweb compartments to clarify the rate of transfer and factors of biomagnification.

Supervisor: Dr. Hugh Henry
Degree: M.Sc. Candidate

Old field habitats are increasing in number as areas previously utilized for agricultural production have been abandoned or converted into naturalized areas. With time and lack of disturbance, old fields develop into secondary forest communities. However, there is concern that climate warming and increased atmospheric nitrogen deposition over the next century may alter plant community successional trajectories. Changes to growing season length and timing as well as nitrogen availability may affect the establishment and competitive abilities of woody seedlings in grass-dominated communities. In this study, I am investigating the effects of both climate warming and increased nitrogen addition on the germination success, establishment, and first year’s productivity of five early successional tree and shrub species in a temperate old field.

Supervisor: Dr. Liana Zanette
Degree: Ph.D. Candidate

Studies usually only measure how many individuals predators kill, and do not assess the equally and sometimes stronger effect of predator-induced fear (i.e. perceived predation risk) on prey populations. I am proposing to assess how perceived predation risk affects prey population dynamics through effects on juveniles, an important but understudied life-history stage. I will fill this gap by manipulating perceived predation risk in wild, free-living song sparrows (Melospiza melodia). Fates of offspring will be monitored once they have left the nest (i.e. fledged) until their death or recruitment into a population the following season, and I will assess the behavioural and physiological reasons why they live or die.

Supervisor: Dr. Amanda Moehring
Degree: M.Sc. Candidate

With the current shifts in global climate, it is critical for us to understand how organisms have adapted to local climate. While D. simulans is thought to be a more genetically variable species, its sister species, D. melanogaster, is thought to be more genetically adapted to its local environment. I tested the hypothesis that D. simulans is more plastic than D. melanogaster. To do this, I determined whether populations of D. simulans and D. melanogaster have adapted to their local environment by comparing their optimum temperatures range at a variety of life stages. Preliminary results indicate that D. simulans has equal levels of fitness in a very wide range of temperatures, whereas D. melanogaster is more sensitive to changes in temperature.

Supervisor: Dr. Brian Branfireun
Degree: Ph.D. Candidate

Anthropogenically-driven habitat loss is the single greatest threat to the biodiversity and functions of Earth’s ecosystems. Therefore, an understanding of, and effective means to quantify, anthropogenic impacts on ecosystem function are urgently needed if we are to effectively mitigate further impact. The aim of my doctoral research is to develop a set of quantitative metrics to measure ecosystem function using wetlands as a model system. In order to even begin to address this overall goal, the first part of my work has led to a critical examination of the terminology and assumptions in the field of ecosystem function research. My conclusion thus far is that scientific progress in this area of Ecology is hindered by the use of ill-defined language and unquantifiable metrics that render generalizable principles elusive.

Supervisor: Dr. Beth MacDougall-Shackleton
Degree: M.Sc. Candidate

Parasites comprise many of the known species in the world and they have significant effects on the health and reproductive success of their hosts. Theory suggests that locally good genes may allow an individual to resist parasites with which they are familiar. This may in turn be an isolating mechanism that can cause populations to genetically diverge. In a song sparrow population in southern Ontario, recent work has improved the ability to distinguish local from non-local individuals more accurately than previously possible. Using multiple measures of immunity and parasite counts, I intend to determine whether local individuals carry more parasites than non-local birds, and also to test whether local birds have inherently greater immunocompetence than their non-local counterparts.

Supervisor: Dr. Bryan Neff
Degree: M.Sc. Candidate

Global climate change is projected to have widespread effects, threatening the viability of natural populations and biological diversity. The ability of species to adjust to climate change is modulated by its adaptive capacity, which likely involves evolutionary adaptation. Physiological processes of aquatic ectotherms critically depend on their thermal environment, such that optima for performance corresponds to historically experienced temperatures. Atlantic salmon (Salmo salar) were extirpated from Lake Ontario by 1900, and current restoration efforts are focused on three candidate source populations. The aim of my project is to evaluate thermal tolerance and its underlying adaptive capacity in these candidate source populations, and identify which would have the highest relative survival and thereby long-term restoration success in Lake Ontario in projected warming temperatures.

Supervisor: Dr. Zoë Lindo
Degree: M.Sc. Candidate

Collembola, also known as springtails, are an ancient and globally distributed group of arthropod soil mesofauna with an important role in ecological processes including decomposition, nutrient cycling, and microbial activity mediation. Their variety of feeding strategies, high densities, and ubiquity make them a major component of soil functioning. However, little is known about how springtail communities will respond to anthropogenic environmental changes to temperature, moisture, and CO₂. This is further complicated by springtail taxonomic and morphological variation, making classic richness-based diversity metrics less meaningful predictors of functioning. My research uses a full factorial design to study the effects of environmental change variables on Collembolan community composition and trait distribution, with an eye towards resulting effects on associated microbes, fungi, and plants.

Supervisors: Dr. Elizabeth MacDougall-Shackleton and Dr. Scott MacDougall-Shackleton
Degree: M.Sc. Candidate

Pathogens present strong selective pressures upon hosts, thus trade-offs involving immunity are crucial in determining optimal life-history decisions. Life-history theory predicts animals face trade-offs with immune defence while performing strenuous exercise, such as migratory flight. Long migratory flight creates a lose-lose scenario where, as travel distance increases, there is an increasing energetic cost while encountering a growing number of foreign pathogens and parasites. Intraspecific variation of migratory distance in a well-studied song sparrow population will be determined using stable isotope analysis. These distances will be compared to a range of immune techniques that assess diverse aspects of the immune response. My objective is to determine whether trade-offs exist within the innate and adaptive branches of the immune system to optimize life-history decisions and energy allocation.

Supervisor: Dr. Beth Macdougall-Shackleton
Degree: Ph.D. Candidate

The local adaptation hypothesis predicts that subpopulations are better adapted to their local environment than to other environments. In the context of a songbird host-bloodborne parasite system, I hypothesized that host individuals remaining to breed close to where they were born should be better able to defend against the local parasites, relative to hosts immigrating from other populations. To test this, I captured song sparrows from different locations around Eastern Ontario. I used genetic assignment tests to estimate the degree to which individuals breeding in a location were of local origin (“assignment index”), and also assessed blood-borne parasite load. My results support the local adaptation hypothesis and suggest an important role for parasites in restricting host dispersal.

Supervisor: Dr. Zoë Lindo
Degree: M.Sc. Candidate

The use of natural model systems, such as the bryosphere, are critical in predicting the response of ecosystem C- and N-budgets to global environmental change. Within the bryosphere, the symbiotic association between cyanobacteria and mosses is known to fix atmospheric nitrogen (N) and supplement ecosystems with bio-available N. However, the impact of global change factors including temperature, N-addition, and CO 2 on the N-fixation process—biological nitrogen fixation (BNF)—remains largely unstudied. The present research explores the response of BNF by the cyanobacterium Nostoc punctiforme to global change factors in laboratory, greenhouse, and field settings. By using a multi-setting approach with a full factorial experimental design, the study aims to predict how environmental changes interact to alter N dynamics within terrestrial ecosystems.

Supervisors: Dr. Norman Hüner and Dr. Denis Maxwell
Degree: M.Sc. Candidate

Previous studies from the Maxwell/Hüner group has shown that based on Internal Transcribed Spacer sequencing a previously unknown green alga isolated from Antarctica is in fact a strain of Chlamydomonas raudensis. However, unlike the type strain of C. raudensis (SAG 49.72), the Antarctic strain (UWO241) is psychrophilic - that is it has an optimum growth temperature below 15ºC and dies above 20ºC. So, although these two strains are the same species, their growth habit is very different. For my specific project, I have employed a RAPD based approach for genome characterization of these two strains of C. raudensis. In this study I have employed different 13 nucleotide long random primers for genome wide polymorphism survey of UWO & SAG along with 3 closely related strains of Chlamydomonas reinhardtii to see the extent of genomic variation between UWO & SAG in comparison to the model alga C. reinhardtii strains.

Supervisor: Dr. Bryan Neff
Degree: Ph.D. Candidate

Understanding the resource use of individuals provides insight not only into food web structure, but also other ecological and evolutionary processes. Using stable isotopes of carbon and nitrogen as a tool to examine resource use my research has covered three main projects. First, resource use and morphology of alternative reproductive tactics of bluegill sunfish (Lepomis macrochirus) was examined to test potential trade-offs between natural and sexual selection. Second, I examined the resource use of pumpkinseed sunfish (Lepomis gibbosus) in freshwater lakes following the invasion of zebra mussels. Finally, the role of resource polymorphisms within populations as a factor in speciation was tested by examining both diet and assortative mating using stable isotopes. The goal of my research is to provide insight into the important roles foraging ecology plays in natural populations.

Supervisor: Dr. Liana Zanette
Degree: Ph.D. Candidate

Supervisor: Dr. Bryan Neff
Degree: Ph.D. Candidate

Since Hamilton formally described kin selection theory, biologists have been interested in how animals can recognize their kin. Indeed, over 250 species have been shown to discriminate kin from non-kin. However, the way that an animal’s ecology influences the evolution of its kin recognition mechanism has been largely ignored. In my thesis, I used two species of teleost fish, bluegill (Lepomis macrochirus) and guppies (Poecilia reticulata), to investigate the influence of mating system on the evolution of kin recognition. In both species, the level of promiscuity reliably predicts the recognition mechanism used, revealing the importance of an animal’s ecology on the evolution of kin recognition.

Supervisor: Dr. Brent Sinclair
Degree: Ph.D. Candidate

Environmental stress interacts with the physiology of individuals to determine an individual’s fitness. While environmental stress is generally characterized by both intensity and duration of that stress, recent work has shown that both physiology and fitness can also be impacted by frequency and period between stress exposures. I used cold tolerance in four different species of Canadian insects with contrasting cold tolerance strategies (the goldenrod gall fly, the eastern spruce budworm, the woolly bear caterpillar, and the fruit fly Drosophila melanogaster) to explore how intensity, duration, frequency, and period of stress all impact and interact in their impacts individual physiology and fitness. I found that in most species, increased frequency of stress tends to reduce fitness even when duration and intensity are controlled.

Supervisor: Dr. George Lazarovits
Co-supervisor: Dr. Greg Thorn
Degree: M.Sc. Candidate

Common scab affects potato crops worldwide leading to high economic losses. In 2002 an estimate of $15.3 to $17.3 million is lost due to common scab in Canada. Soils that are suppressive to common scab have been described. In these soils disease does not develop even though inoculum of the pathogen is present. Adding suppressive soils to soils where disease is prevalent negates disease from occurring and this soil also becomes disease suppressive. The most widely studied agents associated with suppressive soils are members of the Pseudomonas fluorescens group and they have not yet been tested for their impact on the scab pathogen. In this study I intend to investigate the use of strain(s) from the genus Pseudomonas in developing suppressive soils to common scab.

Supervisor: Dr. Bryan D. Neff
Degree: M.Sc. Candidate

Evaluating the evolutionary potential of species to adapt to warming temperatures is critical for understanding the biological impacts of climate change. For aquatic ectotherms, such adaptive responses will likely involve adjustments of their optimum temperature (T_opt) and their upper critical temperature (T_crit. We used a quantitative genetic breeding design to evaluate the genetic architecture underlying T_opt and T_crit within a population of Chinook salmon (Oncorhynchus tshawytscha). Additive genetic, non-additive genetic, and maternal effects explained 32%, 19%, and 0% of the phenotypic variance in T_opt, respectively, while these effects explained 17%, 0%, and 5% of the variance in T_crit. These results suggest that adaptation from standing genetic variation for both T_opt and T_crit may be possible in this population as an evolutionary response to changing temperatures.

Supervisors: Dr. Irena Creed and Dr. Charles Trick
Degree: M.Sc. Candidate

The RTgill-W1 cell line and erythrocyte lysis assays were studied and manipulated in an attempt to develop fast, reliable, low volume, and high throughput screening methods of toxic and noxious freshwater algal compounds. Through the use of various analytical standards and extracts from freshwater cyanobacteria and chrysophyte cultures, both bioassays have been evaluated in terms of their sensitivity to the toxic and noxious compounds commonly produced in Ontario lakes. A number of these compounds have been determined to be appropriate for detection by the bioassays, suggesting that these assays may be appropriate for wide scale use. Successful adaptation of these assay methods will improve the screening efficiency and capacity for investigators of water quality and bloom dynamics.

Supervisor: Dr. Scott Petrie
Co-supervisor: Dr. Christopher Guglielmo
Degree: M.Sc. Candidate

Severity of weather necessary to cause southern migration by waterfowl may differ among species. Some species of duck may migrate independently of weather severity, where migration results from endogenous rhythms related to photoperiod. A Weather Severity Index (WSI) was developed for mallards (Anas platyrhynchos; Schummer et al. 2010) and used temperature and snow cover data to explain change in relative abundance of mallards at mid-latitude staging areas during autumn-winter. I aim to investigate the relative contribution of weather and photoperiod cues for other species of dabbling ducks using data from standardized waterfowl surveys conducted throughout eastern North America, September – February. Developed WSIs for each species of duck will be modeled with future climate change scenarios to determine how duck distributions may vary with climate change.

Supervisor: Dr. Edward Topp
Co-supervisor: Dr. Hugh Henry
Degree: M.Sc. Candidate

The veterinary drugs (antibiotics and antiparasitics) are fed to or injected into livestock animals to increase their growth, prevent outbreaks of disease and treat sick animals in the herd. These compounds and their metabolites are then excreted and are released to the environment through manure application. Once released, they can influence whole soil communities. I will investigate the changes in soil communities due to three drugs, comparing mixture effect vs. single drug effect, two concentrations (high and low dose), and several time points (acute effect, recovery, chronic effect). I will sample the soil in treated microplots and determine the rates of nitrogen transformation: degradation of organic matter, mineralization and nitrification rates; and use molecular techniques to determine abundance of organisms responsible for these processes.

Supervisor: Dr. Scott Petrie
Co-Supervisor: Dr. Hugh Henry
Degree: M.Sc. Candidate

Around 1970, wetland loss and conversion to agriculture necessitated Eastern Population Tundra Swans (TUSWS) to incorporate waste agricultural grains into their diets in addition to traditional foods. Identifying how TUSWs select wetland and terrestrial habitats in altered landscapes is essential to assess TUSWs’ biological requirements, predict effects of habitat change, test hypotheses underlying ecological processes and enable conservation strategies to ensure adequate foraging habitats are available for swans. I will use satellite telemetry data from 55 Eastern Population TUSWs to investigate seasonal selection of agricultural and wetland habitats during the nonbreeding period. My objective is to determine if habitat selection differs seasonally at the Atlantic Coast, Great Lakes, Prairies, and Northern Boreal Forest and how nutritional requirements, food availability and habitat accessibility influences habitat use..

Supervisor: Dr. Nusha Keyghobadi
Degree: M.Sc. Candidate

Communities that occupy container-like habitats, such as the northern purple pitcher plant, are ideal for research on metapopulation and meta-community structure due to co-occurrence of multiple species within spatially well defined habitat patches. The northern purple pitcher plant, Sarracenia purpurea, is the exclusive larval habitat for the flesh fly, Fletcherimyia fletcheri. This study intends to examine the effects of broad scale landscape configurations and composition on the genetic community structure of flesh flies in habitat patches across Algonquin Provincial Park. Through the use of spatially oriented genetic samples we hope to develop a viable system model that will be able to predict rates of gene flow between regions based on least cost pathway analyses of the landscape composition across 15 locations across the park.

Supervisor: Dr. Brock Fenton
Degree: M.Sc. Candidate

Bat communities consist of many species with similar diets. A competitive view of niches suggests that bats partition available resources. I placed two microphone arrays in cluttered, edge and open habitats and recorded continuously from sunset to sunrise in the vicinity of Windsor Cave in Jamaica. From these recordings I reconstructed flight paths of bats whose echolocation calls were recorded. I also captured bats including Molossus molossus, Tadarida brasiliensis, Mormoops blainvillii, Pteronotus parnellii, Pteronotus quadridens, Pteronotus macleayi, using mist nets and harp traps and took morphological measurements. Differences in morphology, habitat selection, periods of peak activity and flight speeds emerged from a comparison among the different insectivorous species. I found sympatric bats differed from one another in at least one of the factors I studied.

Supervisor: Dr. Scott Petrie
Co-Supervisor: Dr. Irena Creed
Degree: M.Sc. Candidate

Research indicates that the timing of spring migration by lesser scaup is fixed relative to other waterfowl. In contrast, mallards, as habitat generalists may adjust timing of migration based on annual differences in weather. Combined data from lesser scaup and mallards enable us to test hypotheses about the relative contribution of photoperiod and weather metrics on timing of spring migration in birds. I will use satellite tracking data from lesser scaup and annual spring migration surveys to determine the influence of photoperiod and weather metrics on spring migration chronology and peak migration dates of lesser scaup and mallards. My objective is to test the relative influence of photoperiod and developed weather indices hypothesized to influence migration chronology in waterfowl.

Supervisor: Dr. Brock Fenton
Degree: M.Sc. Candidate

Flower-visiting bats are important pollinators of many species of angiosperms. Flower-visiting bats can be generalist or specialist pollinators, where specialists pollinate only a few plant species and generalists pollinate many. Many studies have investigated specialization in pollination systems from the perspective of the plant, by compiling lists of flower visitors and pollinators, however, comparatively few studies have investigated pollinator specialization from the perspective of the flower-visitors. In this study I aim to classify five species of flower-visiting bats in terms of their specialization for pollination using microscopic observations of pollen present in guano to quantify the number of different plant species visited by the bats within one foraging bout and one season.

Supervisors: Dr. Gordon Southam and Dr. Sheila Macfie
Degree: M.Sc. Candidate

When plant roots grow into the soil, they create a rhizosphere. The release of plant metabolites promotes the growth of microorganisms within the rhizosphere, where they in turn alter the geochemical environment through the release of their metabolic products. The microorganisms can also increase the solubilisation of essential nutrients and some symbiotic organisms can promote metal tolerance. This interaction among plant roots and microorganisms shifts to change the physiochemical and biological soil properties. My project investigates the effects of a rhizosphere on metal bioavailability and microbial activity in a metal-polluted soil. The results suggest that metal bioavailability and microbial activity were higher within the rhizoshere, which was reflected by the decrease in the pH, while the microbial diversity was not affected by the growth of plant.

Supervisor: Dr. Brian Branfireun
Degree: M.Sc. Candidate

There is considerable interest in the mercury dynamics of the peatland-dominated watersheds of Canada’s Hudson Bay Lowlands in light of current and future climate and land-use changes. Little data exist on mercury (THg and MeHg) concentrated in the various abiotic and biotic components of the lotic ecosystems of the region, making assessments of future changes to Hg cycling difficult. As part of an ongoing monitoring program at the DeBeers Victor Mine near Attawapiskat, Ontario, small-bodied fish have been collected annually since 2008 from first- and second-order tributaries. Analysis of this data shows evidence of within-species variability over a relatively small geographic region, confounding the concept of ‘reference’ or ‘unimpacted’ sampling locations and populations. This unprecedented dataset will generate a baseline understanding for the ongoing monitoring of Hg in the far north.

Supervisor: Dr. Jack Millar
Degree: M.Sc. Candidate

There is variation in the mean breeding initiation date of Peromyscus maniculatus populations among years and the reason for this is unknown. In this study, carbon and nitrogen stable isotopes of hair of the deer mouse Peromyscus maniculatus were used to determine how overwintering diet quality varied among the years of 2004-2011. Then, the relationship of these yearly values was annual mean initiation of breeding date was examined. It has been found that mean hair carbon isotope values of adult P. maniculatus vary among years, which may be due to a yearly climatic effect on plant sources. Adult mean nitrogen isotope values did not vary among years. Adult 13C and 15N values do not appear to be correlated with initiation of breeding dates.

Supervisor: Dr. Charles Trick
Degree: M.Sc. Candidate

The community in Naivasha, Kenya, believes that environmental contaminants pose a risk to their health. This concern stems from the massive increase in agricultural activity, industry and urban centers in Naivasha over the past 3 decades. All 3 of these human activities are often correlated with increasing levels of contamination by harmful chemicals, such as persistent organic pollutants and metals. My study explores the distribution of these contaminants in Naivasha’s sediment and dust and the potential risk that exposure poses to human health.

Supervisor: Dr. Brock Fenton
Degree: M.Sc. Candidate

Little is known about migratory bat movement across the landscape, however, studies suggest that linear geographical features may be important navigational markers during migration. My study explored activity patterns of migratory bats along north-south oriented landscape features in southwestern Ontario. Acoustic monitoring was used to indicate bat activity for two species, L.Cinereus and L. Borealis, at ridge and shoreline features. The levels of bat activity in relation to landscape features may indicate areas of significance for migratory bats during their annual seasonal movements and may also inform the placement of future wind turbines.

Supervisor: Dr. Nusha Keyghobadi
Degree: M.Sc. Candidate

A fundamental goal of landscape genetics is to understand how landscape structure influences gene flow. Little is known about how the composition and configuration of habitat in a landscape contributes to patterns of genetic divergence. We investigate the relative contribution of landscape composition and configuration to patterns of genetic structure in the pitcher plant midge, Metriocnemus knabi, across spatial scales. As a larval inhabitant of the pitcher plant, the habitat of M. knabi is defined and organized among pitcher leaves, plants, clusters, and bogs. Using the amount of habitat, the size of habitat patches, and the degree of isolation among habitat patches as metrics of landscape composition and configuration, and hierarchical F-statistics as metrics of genetic structure, we examine this key question in landscape genetics.

Supervisor: Dr. Greg Thorn
Degree: Ph.D. Candidate

The evolution of reduced fruit body morphology (“cyphelloidism”) in the mushroom fungi is poorly studied and understood, especially within the Resupinateae. How many times has the cyphelloid habit evolved within the group? Do all cyphelloid members that are treated in this group belong? Are there other species of cyphelloid fungi treated in other genera that belong within the Resupinateae? I will present a preliminary phylogeny of the cyphelloid and lamellate members of the Resupinateae based on rDNA sequences to illustrate the evolution of the reduced basidiomata. For morphological studies, the few herbarium specimens associated with many species names may lead to false impressions of geographic range. In contrast, some previously suggested synonymies and reports based on misidentifications mask genuine patterns of geographic range.

Supervisor: Dr. Amanda Moehring
Degree: Ph.D. Candidate

Although the costs of mating to females are high, females of many species are polyandrous. The benefits females receive from mating with multiple males must counteract costs. Polyandrous females can impose selection on males through mechanisms of postmating sexual selection. Postmating sexual selection is an important evolutionary force that can change allele frequencies within a population and drive sexual selection, and can also create divergence between populations that can eventually lead to speciation. My research will study postmating sexual selection at the molecular, cellular, and organism level using Drosophila as a model. The broad goal is to tease apart the antagonistic postmating sexual selection relationship between females and males.

Supervisor: Dr. Brent J. Sinclair
Degree: M.Sc. Candidate

Climate change is rapidly altering abiotic conditions at species range-edges and many organisms will have to shift their geographic ranges to accommodate the new conditions. However, gene flow can limit a species’ range by swamping the ability of a species to adapt to local conditions. An estimate of the amount of gene flow required to inhibit local adaptation has not been experimentally investigated. I use laboratory populations of Drosophila melanogaster under selection for desiccation resistance and quantify adaptation, as well as the physiological response to selection, in range-edge populations subject to migration from the core population. Preliminary results indicate my methods of selection were successful, but there was no response of gene flow on adaptation as measured by survivorship to the selection pressure.

Supervisor: Dr. Brock Fenton
Degree: M.Sc. Candidate

Specialized stomach morphology can lead to important consequences in the dietary strategies of frugivorous animals. Food passage times and dietary selection are two such characteristics determined by these adaptations. This can easily be observed in sympatric New World leaf-nosed bats such as Ariteus flavescens, Artibeus jamaicensis, and Glossophaga soricina. Although these species all eat fruit, they exhibit different stomach morphologies and dietary strategies. Ariteus flavescens, a very poorly understood endemic Jamaican species, purportedly has skeletal muscle in its stomach walls leading to a unique feature within the mammalian class. Through fecal analysis and feeding experiments I will examine the food passage times relative to the diet and roosting preference of each species to determine the biological and ecological implications of each strategy.

Supervisor: Dr. Amanda Moehring
Degree: M.Sc. Candidate

The lock and key model has long been used as an explanation for highly divergent male genitalia in sister species. Although it initially seems intuitive, much controversy surrounds the model as it is difficult to test. The sibling species Drosophilia simulans and D. mauritiana have long been suspected to be a prime example of the lock and key model as the only apparent morphological difference between them is the male genital arch, but little evidence has been previously reported on its validity. The purpose of my study is to investigate what role morphological factors play on the reproductive isolation of these two species, therefore determining if the lock and key model is a viable explanation for species isolation.

Supervisor: Dr. Brian Branfireun
Degree: M.Sc. Candidate

Regional atmospheric mercury emissions have been declining since the late 1970s, and although organismal concentrations of mercury are expected to decrease concurrently, the bioavailability of mercury in some areas is complicated by many factors. Continuing research in one such area, Lake Erie, has revealed a recent (post-1990) rising of mercury concentrations in its top predatory fish. The purpose of my study is to examine the trophic changes in the lake resulting from introduced benthic invasive species, determining the role they play in mercury bioaccumulation in higher organisms. I will also be monitoring mercury levels in biotic and abiotic samples after storm and sediment re-suspension events to determine the role of these occurrences in lake-wide mercury cycling.

Supervisor: Dr. Brock Fenton
Co-supervisor: Dr. Fred Longstaffe
Degree: M.Sc. Candidate

Stable isotope analysis has become an important tool to study bat ecology. Stable hydrogen isotope ratios (δD) in particular can be very useful for determining if migration occurs and if so, at what distance bats migrate. Little is known, however, about the effect of trophic level on δD values in bat fur. Understanding the effect of trophic level on δD variation can help to refine our understanding of migration in bats as well as provide additional information about their diets. I will conduct stable isotope analyses on several bat species, both captive and wild, to determine if there is an effect of trophic level on the stable hydrogen isotope ratios in bat fur.

Supervisor: Dr. Hugh Henry
Degree: M.Sc. Candidate

Old field habitats are increasing as areas previously utilized for agricultural production have been abandoned or converted into naturalized areas. With time and lack of disturbance, old fields develop into secondary forest communities. However, there is concern that predicted global changes in climate and nutrient deposition will alter the composition and dynamics of plant communities. Specifically, increases in temperature and nitrogen deposition may have an impact on the ability of woody species to germinate and compete with established grasses in old field environments. In this study, I will be examining the effects of increased temperature and nitrogen deposition on the survival, growth, and competitive ability of several early successional species commonly found in temperate old fields.

Supervisor: Dr. Scott Petrie
Degree: M.Sc. Candidate

Decisions to develop offshore areas of the Great Lakes with industrial wind turbines were preceded without adequate research on impacts to animal movements and migration. Planned development of industrial wind turbines throughout the lower Great Lakes may affect overwintering sea duck populations because of their placement in areas where ducks may forage and roost during winter. Movement patterns and habitat selection by animals are used to infer resource patch availability, habitat quality, estimate minimum space requirements, and evaluate the plasticity of individuals to habitat change. Long-tailed Ducks (Clangula hyemalis), the most abundant sea duck overwintering at Lake Ontario, will be implanted with satellite transmitters to investigate environmental variables hypothesized to influence movement patterns and habitat selection in the nearshore and offshore habitats of Lake Ontario.

Supervisor: Dr. Yolanda Morbey
Degree: M.Sc. Candidate

Chinook salmon (Oncorhynchus tshawytscha) were first successfully introduced to the Great Lakes in the 1960’s. Since then, Chinook have colonized tributaries throughout the Great Lakes with variable success resulting in differential rates of fish production. The early life history (egg deposition-emergence) of Chinook salmon is associated with high mortality rates and can significantly influence fish recruitment rates. The Nottawasaga River, Sydenham River (both in Lake Huron), and Credit River (Lake Ontario) have very different recruitment rates and little is known about the underlying factors contributing to this difference. The purpose of my study is to investigate how maternal traits, egg quality, habitat quality and habitat quantity affect early life history survival in Chinook salmon and how this influences tributary recruitment rates in the Great Lakes.

Supervisor: Dr. Graham Thompson
Degree: M.Sc. Candidate

The evolution of reproductive altruism was a substantial challenge to Darwin’s theory of natural selection. How can altruistic castes evolve if they produce few or no offspring? Hamilton resolved Darwin’s dilemma by showing that altruist fitness can be maximized if ‘genes for altruism’ are passed indirectly through reproducing relatives. Despite this understanding from inclusive fitness theory, we do not yet know how these genes function, not even for eusocial honey bees for which whole-genome analyses are possible. In this study I use bioinformatic tools to reconstruct gene networks that describe worker altruism in terms of ovary activation. Specifically, I link candidate gene lists with gene-function information to assemble provisional networks, then test the characteristics of each construct against expectations arising from social gene theory.

Supervisor: Dr. Beth MacDougall-Shackleton
Degree: M.Sc. Candidate

Birdsong, like many mating signals, has multiple aspects to which receivers can attend. One such aspect is vocal performance, defined as the ability to perform a physically demanding song. While previous studies have shown that female song sparrows (Melospiza melodia) may use song complexity and local song structure when selecting a mate, the role of vocal performance in mate choice remains unknown. I will examine the causes and consequences of variation in vocal performance in song sparrows, by investigating the relationship between vocal performance and male quality, and testing for morphological constraints on performance. If variation in vocal performance is found to reflect male quality and/or influence female mate choice, this would represent an important advance in our understanding of birdsong as a complex signal.

Supervisor: Dr. Bryan Neff
Degree: M.Sc. Candidate

Recently, Pacific salmon (Oncorhynchus spp.) have demonstrated remarkable physiological adaptations to their thermal migratory conditions, with populations’ optimum temperature for aerobic scope (T opt) matching historic temperatures during their spawning migration. However, because ectothermic organisms become thermally limited when their aerobic scope is reduced, these population-specific differences cause some stocks to be particularly vulnerable to warming temperatures. In my proposed research, I am going to examine the genetic and environmental contributions to the T opt of several populations of Chinook salmon (Oncorhynchus tshawytscha) by employing a quantitative genetic breeding design and conducting reciprocal translocation experiments. By describing the heritability and plasticity of T opt , this study will further our understanding of how these iconic fish may be able to respond to natural selection under climate change.

Supervisor: Dr. Jeremy McNeil
Degree: M.Sc. Candidate

°ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â Bean Cutworm (WBC, Straicosta albicosta), a dry bean and corn pest, is native to °ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â United States. In recent years this insect has expanded its range eastwardly as far as New York State and northwardly as far as Timiskaming County, Ontario, and parts of Quebec. Although no significant economic damage has yet been reported in Ontario or Quebec, there is fear that this insect might soon be a major pest, causing great economic damage if not controlled properly. To properly control this agricultural pest, its reproductive behaviour needs to be understood. This study will be conducted in both the lab and the field and will follow the reproductive biology of male WBC moths under different biotic and abiotic factors.

Supervisor: Dr. Jeremy McNeil
Degree: M.Sc. Candidate

The °ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â bean cutworm (WBC) is an insect pest of corn and dry beans, and is a cause of crop yield loss and quality reduction in areas where it occurs. Until recently this native species has been restricted to the °ÄÃÅÁùºÏ²Ê¿ª½±Ô¤²â United States. However, in the last decade there has been an eastward movement of WBC and significant numbers are now found in Ontario and Quebec, where there are concerns that this species may become a major pest. Very little is known about reproduction of WBC, yet any rational management plan, must be based on a solid understanding of the basic behavioural and chemical ecology of the target pest. This project will investigate effects of biotic and abiotic factors on reproductive biology of WBC females.

Supervisor: Dr. Amanda Moehring
Degree: M.Sc. Candidate

With the current shifts in global climate, it is critical for us to understand how organisms historically have adapted to local climate and their potential future ability to respond to changes, particularly in temperature. Drosophila simulans and D. melanogaster are closely related species that are both found worldwide. I will test the hypothesis that D. simulans is more phenotypically plastic than D. melanogaster, which is thought to be a more genetically adapted species. To do this, I will determine whether populations of D. simulans and D. melanogaster that were sampled from locations across the world have adapted to their local environment by comparing their optimum fitness temperatures at a variety of life stages (eggs, larvae, and adult fecundity). Each experiment will involve subjecting flies to six temperatures (14, 18, 21, 24, 27, and 30°C) and assessing their survival, development, and reproductive success. This study will determine if there is a difference in optimum temperatures, compare these differences to determine the degree of genetic variability among populations, and finally, determine the overall phenotypic plasticity of each species.

Supervisors: Dr. Jeremy McNeil and Dr. Chris Guglielmo
Degree: Ph.D. Candidate

Insects migrate in order to escape deteriorating habitats and colonize new ones. According to the ‘oogenesis-flight syndrome’, migration in female insects is physiologically incompatible with reproduction. The vast majority of insect species that emigrate from deteriorating habitats do so as sexually immature (post-teneral and pre-reproductive) individuals, and oogenesis inhibits migratory behaviour. However, a prolonged pre-oviposition period where resources are directed to flight machinery (larger wings, body size and muscles) and fuel (lipids) used during the migratory period could have a negative effect on subsequent reproductive output, even if the migrants succeed in locating a suitable habitat. Using the true armyworm, this study would address differences between migrants and non-migrants to see if adaptations mitigate the costs of migration on future reproduction.

Supervisor: Dr. Chris Guglielmo
Degree: Ph.D. Candidate

The energetic demands of avian migration have been extensively studied, but considerably less is known about migratory bats. As both birds and bats are flying endotherms, they are subject to similar ecological pressures and their adaptations to migration are predicted to be convergent in many respects. One major difference between birds and bats is the timing of their reproduction with respect to migration. Unlike birds, reproductive activity (i.e. mating, pregnancy) in bats overlaps with the migration period. The aim of my research is to investigate how bats manage their energy budget as they migrate and compare the strategies of males and females. I will use a variety of methods to estimate energy expenditure during non-flight periods and quantify fuel stores in silver-haired bats during migration.

Supervisor: Dr. Chris Guglielmo
Degree: M.Sc. Candidate

Songbirds depend on stopover sites during their annual migration to accumulate sufficient fat and lean mass to fuel long-distance flight. Although it is now recognized that lean mass is an important component of fuel for birds, the factors that determine variation in the deposition of fat and lean mass are very poorly understood. Quantitative magnetic resonance (QMR) is a new non-invasive method that allows quick, accurate and repeated measurement of fat and lean mass of birds in the field. Therefore, to refine our knowledge of changes in body composition, we used QMR to measure fat and lean mass changes and investigated the influence of season, sex and age on fuel accumulation at a stopover site for 30 passerine species in Long Point, Ontario.

Supervisors: Dr. Rob Nurse and Dr. Hugh Henry
Degree: M.Sc. Candidate

In 2010 a giant ragweed biotype in Southwestern Ontario was confirmed to be the first plant species in Canada resistant to glyphosate. The goals of my study were to determine if growth environment interacts with herbicide injury, if resistant seedlings could be controlled at early growth stages, and if resistance is associated with a fitness penalty. My results suggest that growth environment did not interact with glyphosate injury and resistant seedlings sprayed with glyphosate survived treatment at all leaf stages and herbicide doses. The results of the fitness experiments are still pending; however, if resistance delays flowering and there are less resources provided to dormancy and viability, there may be an impact on the longevity of giant ragweed seed in the soil seed bank.

Supervisor: Dr. Charles Trick
Degree: M.Sc. Candidate

With our global population rising, and demands for water increasing, cyanobacterial blooms threaten the world’s freshwater resources. Cyanobacteria can produce cyanotoxins, which can lead to illness or death if ingested. The cyanobacterial community was studied in Lake Naivasha, Kenya, a eutrophic, human-influenced lake. From August 2010 to March 2011, a cyanobacterial bloom, dominated by the toxin-producing genus Microcystis, proliferated on the lake. Average in situ chlorophyll concentrations reached a high of approximately 100 µg/L in March 2011. Preliminary results suggest that the hepatotoxin, microcystin, was present in small amounts. By May 2011, the bloom dissipated, and the algal community was dominated by a small desmid. Examining the lake in these different states will lead to better understanding of the ecosystem dynamics and threat for future blooms.

Supervisors: Dr. David Sherry and Dr. Scott MacDougall-Shackleton
Degree: Ph.D. Candidate

The adaptive specialization hypothesis posits that cognition and the brain are specialized to serve specific ecological functions. Female brown-headed cowbirds search for host nests, whereas males do not. Females have a larger hippocampus than males, a sex difference that is the reverse of that found in many other species. I will measure aspects of spatial memory in female and male cowbirds using touchscreens and a foraging task. The adaptive specialization hypothesis predicts superior female spatial ability. I also expect to find more a pronounced sex difference during breeding, when females have a higher demand for spatial memory. Finally, I will also determine if performance is correlated with hippocampal size and if this size difference varies with breeding condition.

Supervisor: Dr. Yolanda Morbey
Degree: M.Sc. Candidate

The goal of my study was to determine if introduced Chinook salmon in the Sydenham river, Lake Huron, are pre-adapted for spawning timing. In native populations, there is a seasonal decline in reproductive lifespan and a corresponding decline in fat stores, minimizing the probability that later arriving females will reuse nests. Typically, native Chinook salmon spawn 88 - 98% of their eggs. In the Sydenham river however, spawning is occurring early, thus fish are initially experiencing higher than optimal temperatures for spawning. Additionally, no seasonal decline in either reproductive lifespan or fat stores was found and percentage of eggs spawned was 74 ± 11%. These data imply that reproductive timing of Chinook salmon does not appear to be pre-adapted in this system.

Supervisor: Dr. Brock Fenton
Degree: M.Sc. Candidate

The question of how bat communities are structured and whether there is inter or intraspecific competition for food remains inconclusive, with some studies supporting competition and other studies showing there is no competition. The purpose of my research is to examine different aspects of the insectivorous bats that occur in the Great Windsor Cave, Jamaica. If competition was the driving factor in the evolution of the bat community in Jamaica, then differences in phenotypic traits, including body size, wing morphology and echolocation calls, should be observed. I will compare inter-species diet, flight patterns during hunting, echolocation call structures, skull and wing morphology and patterns of habitat use, to show that bat communities have reduced competition by exploiting different food resources.

Supervisors: Dr. Irena Creed and Dr. Charles Trick
Degree: M.Sc. Candidate

The spatial variability of algal blooms in Ontario’s freshwater lakes provides a challenge for investigators seeking to assess the biological impacts of toxic and noxious bloom events. Several small scale bioassays have been developed for detection of freshwater pollutants, but few attempts have been made to modify these assays for the purpose of freshwater algal compound analysis. The RTgill-W1 cell line and erythrocyte lysis assays will be studied and manipulated in an attempt to develop fast, reliable, low volume, and high throughput screening methods of toxic and noxious freshwater algal compounds. Successful adaptation of these assay methods will improve the screening efficiency and capacity for investigators of water quality and bloom dynamics.