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Full-Text Articles in Life Sciences

Hitchhiker's Guide To Migration: Effects Of Experimental Parasitic Infection And Other Immune Challenges On Migratory Traits Of Sparrows, Tosha R. Kelly Nov 2018

Hitchhiker's Guide To Migration: Effects Of Experimental Parasitic Infection And Other Immune Challenges On Migratory Traits Of Sparrows, Tosha R. Kelly

Electronic Thesis and Dissertation Repository

Seasonal migration exposes animals to a variety of habitats and parasites, and if infected migratory birds migrate successfully there is great potential for birds to transport infectious diseases long distances. Our current understanding of whether birds contribute to the spread of disease relies upon observational field studies that are limited in their ability to discern cause from effect. Using captive and field-based experiments for my doctoral research, I answered three research questions: (1) are nocturnal migratory restlessness (Zugunruhe) and body condition affected by mounting an acute phase immune response during migration; (2) what are the impacts of parasitic …


The Effects Of Perceived Predation Threat On Stress Response And Memory In Birds, Chlöe S. N. Carter Oct 2018

The Effects Of Perceived Predation Threat On Stress Response And Memory In Birds, Chlöe S. N. Carter

Electronic Thesis and Dissertation Repository

This study examined how perception of predator cues, across three sensory modalities, affects physiology and behaviour of songbirds. I hypothesized that the perception of predator threat would elicit physiological and behavioural responses in both acute and chronic exposure conditions. My first study examined the responses of wild-caught black-capped chickadees (Poecile atricapillus) and house sparrows (Passer domesticus), as well as lab-bred zebra finches (Taeniopygia guttata), to acute predation cue exposure by coding video recorded behaviour and corticosterone analysis. My second study examined changes in black-capped chickadees’ foraging behaviour and memory retention after chronic exposure to …


The Effect Of Shelter Availability On Foraging In Atlantic Salmon (Salmo Salar), Christian A. Therrien Sep 2018

The Effect Of Shelter Availability On Foraging In Atlantic Salmon (Salmo Salar), Christian A. Therrien

Electronic Thesis and Dissertation Repository

Shelter is an environmental feature that provides protection from danger and its use is an important anti-predator behavior for juvenile Atlantic salmon (Salmo salar). However, how shelter availability influences the foraging of these fish in the wild is not well documented. I predicted that juvenile Atlantic salmon would alter their foraging behavior in a low shelter environment and that this effect would differ between individuals from two populations that are targeted for reintroduction into Lake Ontario. I measured the foraging activity of juvenile Atlantic salmon from the two populations while they were held in pens in a Lake …


Circannual Patterns Of Adipose Tissue Characteristics In A Hibernator, The Thirteen-Lined Ground Squirrel (Ictidomys Tridecemlineatus), Amanda Maccannell Jun 2018

Circannual Patterns Of Adipose Tissue Characteristics In A Hibernator, The Thirteen-Lined Ground Squirrel (Ictidomys Tridecemlineatus), Amanda Maccannell

Electronic Thesis and Dissertation Repository

Obligate hibernators express circannual patterns of body mass and hibernation, which persist under constant laboratory conditions. I hypothesized that in the 13-lined ground squirrel (Ictidomys tridecemlineatus) thermogenic brown adipose tissue (BAT) and lipid storing white adipose tissue (WAT) volume would follow a circannual pattern. I housed animals at either 25°C (thermoneutral) or 5°C with 12h L:12h D photoperiods for an entire year. I determined volume and water-fat ratio of WAT and BAT using magnetic resonance imaging (MRI). BAT volume follows a circannual pattern in both conditions, increasing prior to winter, decreasing in late winter with no change in …