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Early-life Carry-over Effects on Physiology and Survival in a Food-caching Passerine

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Title: Early-life Carry-over Effects on Physiology and Survival in a Food-caching Passerine
Author: Freeman, Nikole
Department: Department of Integrative Biology
Program: Integrative Biology
Advisor: Newman, AmyNorris, Ryan
Abstract: Knowledge of the downstream effects of conditions experienced during early life is essential to understanding the mechanisms driving individual physiology, behaviour, and, ultimately, fitness. Developmental conditions, such as diet quantity and quality, can carry-over to impact a range of physiological and behavioural responses later in life. However, the majority of information we have on early-life conditions comes from well controlled experiments, which may not be representative of conditions in the natural environment or how wild individuals respond to them. In this thesis, I integrate experimental and observational studies to investigate the downstream effects of early-life conditions on Canada jays (Perisoreus canadensis) in Algonquin Provincial Park, ON, Canada. Canada jays are a resident species of the boreal forest that cache perishable food to support overwinter survival and their late-winter breeding season. In my first chapter, I modify and validate a methodology for the extraction and quantification of feather corticosterone, which I use as an integrated measure of hypothalamic-pituitary-adrenal axis activity in subsequent chapters. In my second chapter, I combine a 2-year experiment with 40 years of observational data to demonstrate that Canada Jay nestlings from territories with more available food have higher body condition, lower feather corticosterone, earlier fledge dates, and are more likely to be observed in the fall. In my third chapter, I use stable-carbon and -nitrogen isotopes to estimate nestling diet composition and then show that diet composition does not impact nestling body condition or survival. In my final chapter, I provide evidence that feather corticosterone concentrations in nestling feathers predict juvenile social status while nestling body condition predicts juvenile body condition and survival. Together, my thesis highlights how ecophysiological factors can carry-over from one life-stage to the next, but also demonstrates that wild individuals may be less influenced by certain early-life conditions (e.g. diet composition) than expected.
Date: 2020-11
Rights: Attribution-NonCommercial-NoDerivatives 4.0 International
Terms of Use: All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.
Related Publications: Freeman, N. E., & Newman, A. E. (2018). Quantifying corticosterone in feathers: validations for an emerging technique. Conservation physiology, 6(1), coy051. DOI: 10.1093/conphys/coy051

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