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Full-Text Articles in Life Sciences

Novelty Induces Behavioural And Glucocorticoid Responses In A Songbird Artificially Selected For Divergent Personalities, Alexander T. Baugh, Kailyn Faye R. Witonsky , '16, S. C. Davidson, Laura P. Hyder , '16, M. Hau, K. Van Oers Aug 2017

Novelty Induces Behavioural And Glucocorticoid Responses In A Songbird Artificially Selected For Divergent Personalities, Alexander T. Baugh, Kailyn Faye R. Witonsky , '16, S. C. Davidson, Laura P. Hyder , '16, M. Hau, K. Van Oers

Biology Faculty Works

Stress physiology is thought to contribute to individual differences in behaviour. In part this reflects the fact that canonical personality measures consist of responses to challenges, including novel objects and environments. Exposure to novelty is typically assumed to induce a moderate increase in glucocorticoids (CORT), although this has rarely been tested. We tested this assumption using great tits, Parus major, selected for divergent personalities (bold-fast and shy-slow explorers), predicting that the shy birds would exhibit higher CORT following exposure to a novel object. We also scored behavioural responses to the novel object, predicting that bold birds would more frequently approach …


To Stress Or Not To Stress: Physiological Responses To Tetrodotoxin In Resistant Gartersnakes Vary By Sex, Lorin A. Neuman-Lee, Edmund D. Brodie Jr., Tyler Hansen, Edmund D. Brodie Jr., Susannah S. French Jul 2017

To Stress Or Not To Stress: Physiological Responses To Tetrodotoxin In Resistant Gartersnakes Vary By Sex, Lorin A. Neuman-Lee, Edmund D. Brodie Jr., Tyler Hansen, Edmund D. Brodie Jr., Susannah S. French

Biology Faculty Publications

The activation of the hypothalamic pituitary adrenal (HPA) axis is one of the most important physiological processes in coping with any deviation in an organism’s homeostasis. This activation and the secretion of glucocorticoids, such as corticosterone, allow organisms to cope with perturbations and return to optimal physiological functioning as quickly as possible. In this study, we examined the HPA axis activation in common gartersnakes (Thamnophis sirtalis) as a response to a natural toxin, tetrodotoxin (TTX). This neurotoxin is found in high levels in the Rough-skinned Newt (Taricha granulosa), which is a prey item for these snakes. …


Risk-Averse Personalities Have A Systemically Potentiated Neuroendocrine Stress Axis: A Multilevel Experiment In Parus Major, Alexander T. Baugh, Rebecca A. Senft , '15, Marian L. Firke , '14, Abigail P. Lauder , '15, J. Schroeder, S. L. Meddle, Kees Van Oers, M. Hau Jul 2017

Risk-Averse Personalities Have A Systemically Potentiated Neuroendocrine Stress Axis: A Multilevel Experiment In Parus Major, Alexander T. Baugh, Rebecca A. Senft , '15, Marian L. Firke , '14, Abigail P. Lauder , '15, J. Schroeder, S. L. Meddle, Kees Van Oers, M. Hau

Biology Faculty Works

Hormonal pleiotropy—the simultaneous influence of a single hormone on multiple traits—has been hypothesized as an important mechanism underlying personality, and circulating glucocorticoids are central to this idea. A major gap in our understanding is the neural basis for this link. Here we examine the stability and structure of behavioral, endocrine and neuroendocrine traits in a population of songbirds (Parus major). Upon identifying stable and covarying behavioral and endocrine traits, we test the hypothesis that risk-averse personalities exhibit a neuroendocrine stress axis that is systemically potentiated—characterized by stronger glucocorticoid reactivity and weaker negative feedback. We show high among-individual variation and covariation …


Consistency Of Structural Color Across Molts: The Effects Of Environmental Conditions And Stress On Feather Ultraviolet Reflectance, Rebecca Lynn Windsor Mar 2017

Consistency Of Structural Color Across Molts: The Effects Of Environmental Conditions And Stress On Feather Ultraviolet Reflectance, Rebecca Lynn Windsor

USF Tampa Graduate Theses and Dissertations

Across avian systems, plumage ornamentation is often considered a signal of individual fitness, condition, sex, or status, and varies due to genetics or environmental sources. In species with structural coloration, plumage variation results from differences in the amount of energy allocated to feather growth during molt, presenting a unique opportunity to study the link between individual quality and ornamentation. In cooperative breeding species, such as the Florida Scrub-Jay (Aphelocoma coerulescens), the role of structural color as a signal is particularly important because helpers may delay breeding for one to several years and competition for space is high. Florida Scrub-Jay juveniles …