Western University BiologyWestern Science

Archived Friday Philosophicals Abstracts - Fall Semester 2014

December 05, 2014

Tosha Kelly: The plasticity of migratory behaviour in response to parasitic infection

Tosha KellySupervisors: 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.

Angela Marinas: Reproduction-flight syndrome in the true armyworm, Pseudaletia unipuncta

Army worm mothSupervisor: 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.

November 28, 2014

Nico Munoz

Nico Munoz photoSupervisor: 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.     

November 21, 2014

Malcolm Lau

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Mike Onley: Reproductive Biology of Migrant and Non-Migrant Populations of the Armyworm Moth Pseudaletiaunipuncta

Mike Onley photo

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.

November 14, 2014

Trinh Nguyen: Sexual selection in Drosophila melanogaster
Supervisor: Dr. Amanda Moehring
Degree: PhD

Trinh Nguyen

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.   

Emma Hobbs: Quantifying the effects of perceived predation risk on the avian brain

Emma HobbsMSc 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

November 07, 2014

Blair Dudeck

Blair DudeckPredators 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.

Paul George: A Comparison of Community Composition Analyses for the Assessment of Wood-ash Soil Amendment on Free-living Nematodes

Paul George - NematodesSupervisor: 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.

October 31, 2014

Steve Sharron: Fish Out of Salt Water: Smoltification in Subyearling Great Lakes Pacific Salmon

Steve Sharron - salmonMSc. 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.

October 24, 2014

Andrea Boyer: Effects of simulated recurrent inclement winter weather cues on the stress response and feeding behaviour of white-throated sparrows (Zonotrichia albicollis)

Andrea BoyerClimate 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.

October 17, 2014

Toby Thorne

Toby Thorne 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.

Alesky Paltsev

Alesky PaltsevAleksey Paltsev: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.

October 03, 2014

Vicki Simkovic: Genetic vs. environmental effects on nestmate recognition in the Eastern subterranean termite Reticulitermes flavipes

Vicki SimkovichSupervisor: 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.

Joanna Konopka:Success of native and exotic egg parasitoids (Hymenoptera: Scelionidae) as biological control agents of H. halys (Hemiptera: Pentatomidae)

JOanna KonopkaSupervisors: 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.

September 26, 2014

Matt Dyson: Survival and habitat selection of female wood ducks (Aix sponsa) and broods at Long Point, ON.

Matt DysonCo-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.

Ian Mcdonald: Factors affecting the release of and response to the Stress Odorant (dSO) by Drosophila melanogaster

Ian McdonaldSupervisors: 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.