EEB SEMINAR: FEBRUARY 1

This week we are pleased to welcome Thomas Merkling from the Friesen lab.

Towards a better understanding of offspring sex-ratio variation in vertebrates

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Ever wondered why Celine Dion has three sons and not any other combinations? Sex allocation theory considers the way parents invest in male and female functions according to their relative fitness benefits. Although successfully applied in parasitic wasps for instance, results remain equivocal in birds and mammals. During the talk, two main reasons underlying these inconsistencies will be addressed: the lack of knowledge on 1) the fitness benefits and costs of either sex and 2) the underlying mechanism(s) of sex-ratio biases. First, using a population of a seabird, the black-legged kittiwake (Rissa tridactyla), he investigated both differences in energetic costs and in fitness return between sons and daughters to then predict how offspring sex-ratio should be adjusted. Then, he did a meta-analysis to test for a ubiquitous role of maternal testosterone in sex-ratio biases across birds and mammals. To finish, he will address another remaining mystery: the evolution of environmental sex determination. Using a comparative approach across lizards, he will test the recent prediction that differences in sex-specific survival to maturity can lead to the evolution of temperature-dependent sex determination.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm.

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EEB SEMINAR: JANUARY 25

This week the department is pleased to welcome Marc Bélisle from the Université de Sherbrooke.

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Aerial insectivorous birds experience severe population declines in many parts of North America and Europe. Because many of these species nest above ground in or close to farmlands, the principal cause of their decline has been hypothesized to result from a decreased food availability mainly due to pesticides. Yet pesticides can have both toxicological and trophic effects on birds. Moreover, the amount and diversity of pesticides found in the environment must depend largely upon the type of agriculture performed. In turn, agriculture dictates landscape structure, which also affects insect populations and communities. This talk will present how an army of students is starting to disentangle the links among agricultural landscape composition, prey availability and contamination by pesticides, on various individual performance proxies of Tree Swallows. Most of the results that will be showed origin from a 14-year study of individually-marked Tree Swallows breeding within a network of 400 nest boxes distributed among 40 farms located along a 10 200 km2 gradient of agricultural intensification in southern Québec.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. This week’s seminar will be followed by a pizza lunch outside the seminar room.

EEB Seminar: January 18

This week the department is pleased to welcome Dave Fifield, wildlife biologist with Environment and Climate Change Canada’s Science and Technology Branch.

Predictive Models and Petrel Declines: A Sampling of Applied Marine Bird Research in Atlantic Canada

This talk will highlight two facets of current marine bird research in the Northwest Atlantic involving Environment and Climate Change Canada and collaborators. The first, predictive spatial modelling, is part of a long-term operational program to understand the abundance and distribution of marine birds at sea where they are vulnerable to incidental harm from human activities and face a changing climate. Knowledge of their seasonal distribution is required to assess risk and effectively inform marine conservation planning and policy. To this end Dave will explore the construction of predictive spatial models to generate defensible seasonal seabird density estimates, using a case study in the Labrador Sea. The second part of the talk describes targeted research in response to the recent population decline of Leach’s storm-petrels in Atlantic Canada. This region’s colonies, hosting approximately 40% of the world’s population, have declined by ca. 30% over three generations. Dave will discuss the current state of knowledge and on-going efforts to identify the cause(s) of the decline, highlighting the use of technological innovation in an attempt to illuminate aspects of the decline.

Dave’s main work focuses on applied research to understand the seasonal abundance and distribution of birds in the marine environment using techniques including ship-based and aerial surveys, electronic tagging and tracking, and predictive spatial modelling in order to inform wildlife management, conservation policy, marine protected area design, and risk and damage assessment due to human activities. He also applies his background in Ecology and Computer Science in an attempt to provide innovative technological and analytical approaches to address knowledge gaps in emerging marine bird issues. He is interested in fostering the design and use of structured data management and analysis workflows to increase the production of reproducible research in the biological sciences.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. This week there will be a pizza lunch to follow in the Room 3110.

EEB Seminar: January 11th

This week the department is pleased to welcome our own Catherine Dale for her final departmental seminar.

Should I Stay or Should I Go?  Understanding migratory strategies in western bluebirds

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Partial migration, which occurs when only some animals in a population migrate, is ubiquitous.  However, despite numerous studies investigating how partially migratory systems are controlled, we know relatively little about what determines whether an individual migrates.  In this thesis, I investigate ecological factors and individual characteristics shaping alternative migratory strategies in a partially migratory population of western bluebirds (Sialia mexicana).
First, I ask whether sex, age, or body size are related to variation in migration behaviour.  Using hydrogen isotopes in claw tissue to infer migratory strategy, I show that young bluebirds, particularly young females, are less likely to migrate than older birds, and that bluebirds mate assortatively by migratory strategy.  I also demonstrate that some bluebirds switch strategies between years, indicating that migratory behaviour is not under strict genetic control.  Second, I ask whether individual differences in diet could lead to variation in migratory strategy.  Using nitrogen and carbon isotopes in feathers, I show that the diet of resident males during fall moult differs from that of resident females and migrants of both sexes.  Responses to experimentally presented novel foods suggest this variation could be due to differences in behaviour: resident males are less hesitant to eat novel insects than migrant males, but the opposite is true of females.  Finally, I ask whether two personality traits, boldness and aggression, differ with migratory strategy.  I show that residents are bolder than migrants, but there is no difference between groups in aggression.  However, resident bluebirds from BC are more aggressive than resident bluebirds from California.
My results indicate that social influences, variation in diet, and personality traits may all play a role in determining whether bluebirds migrate.  They also imply that different factors may shape migratory strategies in males and females.  Overall, my research emphasizes the necessity of examining a wide variety of ecological factors and individual characteristics when attempting to determine how partially migratory systems are controlled.  The flexibility of these systems suggests they are likely to shift as a result of global environmental change.  To better predict their responses, an understanding of factors driving variation in migratory strategy is essential.

 

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm.

EEB Seminar: December 7

This week the department is pleased to welcome Risa Sargent from the University of Ottawa.

Alien species introductions – a community perspective

Risa 2017

What are the major impacts of an alien introduction on other species in the community? We know that that aliens compete with, but may also often facilitate, the reproductive success of native plant species. Moreover, alien plant traits are under selection by, and can evolve in response to insect herbivory. The work in my lab demonstrates that the community level impacts of interactions with aliens are complex, and that deep held assumptions may be hindering our ability to identify general patterns.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. This week there will be a pizza lunch to follow in the EEB Lounge.

EEB Seminar: November 30th

This week the department is pleased to welcome Andrew Gonzalez from McGill University.

Diversity, stability and evolution of networks

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In this talk, I will present an approach that views ecological and evolutionary systems as complex evolving networks. For example, network patterns of selection, extinction and colonization can govern the stability and adaptive capacity of communities responding to environmental change.  Species are also connected in networks by their interactions to form food webs, mutualist webs, and host-disease webs. I will integrate these dimensions of ecological networks to show how species interaction networks, such as food webs, reorganize as their component species shift in space through time in response to habitat loss and climate change. 

I will also introduce the idea of community evolutionary rescue. I will explain this new concept and give results from high throughput experimental evolution to show how spatial networks of populations and communities can rapidly evolve in response to extreme environmental stress.

I will close with an application of a network approach to the design of protected ecosystem networks for biodiversity, using the case study of Montreal. This research was a response to a request for knowledge from the Quebec government. Our findings are currently being applied to the design of the green belt and green infrastructure in and around the city.

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. This week there will be a pizza lunch to follow in the EEB Lounge.

EEB Seminar: November 23

This week the department is pleased to welcome our own James Sinclair.

What drives colonist success?

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Colonization plays a central role in much of the theory (e.g. metapopulations) and applications (e.g. biocontrol, invasion, recovery) of ecology. Because of its importance, it is essential that we develop our understanding of, and ability to manage, the colonization process. One of the primary population-level factors that can influence colonist success is the number of colonists. Larger populations are more likely to colonize because they are less vulnerable to the demographic, environmental, and genetic processes that can drive extinction. Applied efforts to control colonist success are likewise often focused on augmenting or reducing the size of colonizing populations. However, there are other, less studied, factors that could also affect colonist success, such as the quality of colonists or the frequency with which new individuals arrive. The goal of my PhD work was to investigate the relative importance of multiple colonist characteristics – specifically population size, colonist quality, and arrival frequency. Is there a single, dominant factor that drives colonist success? Or can their relative importance vary, and if so what might that mean for how we manage colonization?

The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm.