OCT 1 | Frances Bonier, Queen's University, Kingston, Canada
John Bonner Lecture | TITLE: "Stress hormones and life history strategies"
Audience: HOST: EEB Graduate Students
Location: 10 Guyot Hall
Date/Time: 10/01/09 at 12:30 pm - 10/01/09 at 1:30 pm
ABSTRACT: Field endocrinologists have long sought to interpret the biological significance of hormone levels measured in free-ranging animals. Elevated glucocorticoids, or stress hormones, have generally been interpreted to indicate an individual or population in worse condition and with lower fitness relative to individuals or populations with lower glucocorticoid levels (the Cort-Fitness Hypothesis). While the theoretical bases of the Cort-Fitness Hypothesis are sound, empirical data do not always support the hypothesis. Negative, positive, non-linear, and non-significant relationships between glucocorticoids and fitness have been described. In my research, I am exploring the causes of exceptions to the predicted negative relationship between stress hormones and fitness using field investigations of tree swallows. We have found that, even within individuals, relationships between glucocorticoids and fitness components can change across life history stages. We propose that because stress hormones respond dynamically to an individual’s condition, providing ongoing information about the organism’s internal and external environment, these hormones might directly influence investment in reproduction in an adaptive manner. Initial data support this idea, but much work remains to be done to fully explore the relationship between stress hormones and life history strategies.Bonier WEBSITE: http://post.queensu.ca/~bonierf/index.html
Category: EEB 522 Colloquium