Western University BiologyWestern Science

Friday Philosophicals - Winter Semester 2018

Caitlyn Lyons: Aboveground and belowground carbon linkages in Boreal peatlands Kaelyn Bumelis: Niche segregation among three species of swallows in southern Ontario

Caitlyn Lyons: Aboveground and belowground carbon linkages in Boreal peatlands
Kaelyn Bumelis: Niche segregation among three species of swallows in southern Ontario

January 19, 2018

Caitlyn Lyons: Aboveground and belowground carbon linkages in Boreal peatlands

Caitlyn Lyons photoSupervisor: Dr. Zoë Lindo

Climate warming is expected to shift aboveground plant community and this has consequences for belowground microbial community in terms of litter inputs. I will examine the passive warming effects on plant communities in Boreal peatlands, and how potential associated shifts in litter quality will affect microbial carbon use (i.e. whether microbes sequester this carbon as biomass or respire this carbon as CO2). I expect a shift from Sphagnum (moss) dominated communities to Carex (graminoid) dominated communities under warming, and corresponding increases in litter quantity with more easily accessible carbon for microbial communities. Boreal peatlands are an important system to study aboveground and belowground carbon linkages as they have large carbon sequestration abilities associated with low decomposition rates, making them significant global carbon sinks. My research aims to evaluate shifts in Boreal peatland plant communities under passive warming and to determine how changes in litter carbon quality influences microbial carbon use.

Kaelyn Bumelis: Niche segregation among three species of swallows in southern Ontario

Kaelyn Bumelis photoSupervisors: Dr. Keith Hobson

Aerial insectivores are a guild of birds who are facing extensive population declines. However, the rates of these declines vary across species. This is the case for Barn Swallows (Hirundo rustica), Cliff Swallows (Petrochelidon pyrrhonota) and Tree Swallows (Tachycineta bicolor), three aerial insectivore species that breed in Southern Ontario. Although these species share many similarities, Barn Swallows have declined at a much faster rate. One explanation for this is niche partitioning wherein the three species are using the environment differently to limit competition. If the three species exhibit distinct niches, they may be experiencing differential pressures. For my thesis, I will be focusing in on differences in nestling diet and post-fledging movements of these swallow species. Using DNA barcoding and feather stable isotope analysis to examine diet as well as the Motus Wildlife Tracking System to examine post-fledging movements, I hope to find a possible explanation for the differential declines.

January 12, 2018

Christopher Course: Investigating social dynamics in winter flocks of Black-capped chickadees

Christopher Course photoSupervisor: Dr. David Sherry

Seasonality of social behavior is widespread in birds which makes this group an excellent model to study social dynamics like: group fusion-fission, and activity synchronization. Since our understanding of these processes is mostly theoretical, studies that examine social dynamics in an ecological context are needed. I constructed a network of automated radio-towers in a 60 hectare forest to track multiple flocks of radio-tagged Black-capped chickadees through the winters of 2016-2018. Seasonal “radioprofiles” indicate that: flocks can be identified from telemetry data alone, flocks of birds have differing activity schedules, and individual movement between flocks (fission) can be studied. This research shows that automated telemetry can effectively study social behavior on the level of the individual and flock directly in the field. This method provides for a deeper understanding of social evolution by examining real-time social dynamics simultaneously across multiple groups in a natural setting.

Tosha Kelly: Effects of experimental malaria infection on migratory songbird physiology and behaviour

Tosha Kelly photoSupervisors: Drs.  Beth MacDougall-Shackleton and Scott MacDougall-Shackleton

Seasonal migration exposes animals to a variety of habitats and parasites, thus energetic constraints may prevent investing in immunity and migration. If infected birds migrate successfully then there is potential for them to transport infectious disease long distances. To determine whether parasitic infection alters or interferes with songbird migration, I inoculated songbirds with malaria parasites (Plasmodium spp.) in two experiments. First, captive white-throated sparrows (Zonotrichia albicollis) were inoculated in late winter (spring migration), whereby I assessed nocturnal migratory restlessness and body composition (fat mass, lean mass, and hematocrit). Second, I inoculated song sparrows (Melospiza melodia) in captivity and released them prior to fall migration to determine the effect of malaria infection on migratory departure timing. Results indicate that mere exposure to malaria can impact host migratory behaviour and the degree of impact is specific to the stage of infection.

Friday Philosophicals run every Friday in BGS 3000 in the fall term. Seminars are at 3:30pm - 4:30pm.

Speaker Schedule Winter Term 2018

Jan. 19 Caitlyn Lyons (I) Kaelyn Bumelis (I)
Jan. 26 Andrew Chaulk (I) Christine Scharf (I)
Feb. 2 Garth Casbourn (I) Robert Martin (I)
Feb. 9 Olivia Colling (I) Aida Parvizi (I)
Feb. 16 Corrine Genier (I) Claire Bottini (I)
Mar. 2 William Laur (I) Lauren Witterick (I)
Mar. 9 Anna Chernyshova (I) Kevin Erratt (I)
Mar. 16 Jennifer Blythe (I) No second speaker
Mar. 23 Kyra Simone (I) Maryam Jangjoo (E)
Mar. 30  Good Friday
Apr. 6 Nicole Zathey (E) Jing Tian (E)
Babak Ataei Mehr (E, maybe)
I = Introductory Seminar, E = Exit Seminar