Glucocorticoids, environmental challenges, and reproduction in birds
Document Type
Contribution to Book
Source Publication
Hormones and Reproduction of Vertebrates (Second Edition): Volume 4: Birds
Link to Published Version
https://doi.org/10.1016/B978-0-443-16024-0.00008-3
Publication Date
2024
Editor
David O. Norris, Kristin H. Lopez
Publisher
Elsevier
Volume
4
ISBN
978-0-443-16024-0
Department
Biology
Description
Intrinsic trade-offs exist among growth, reproduction, and survival. In this chapter, we use the lens of allostasis to consider the roles of glucocorticoids (GCs) in the conflict between reproduction and survival in the face of environmental challenges in birds. Selection for life-history traits has been posited to shape both patterns of GC release, and responses to elevated GCs. Birds with lower brood value (whether due to environment, life history, or age) are predicted to be more hormonally reactive to challenges and more responsive to GC elevations. In concert with these selective pressures, glucocorticoid levels show a variety of relationships (positive, negative, or neither) with traits related to reproduction, such as feather quality and coloration, body condition, onset of breeding, and parental behavior. Measures of reproductive output (e.g., clutch size, hatching success, and fledging success) also show variable relationships with GC levels—moderate elevations may facilitate investment in reproduction, whereas higher elevations can disrupt it. This chapter investigates the role of GCs in regulating reproductive effort (i.e., the proportion of available energy expended on reproduction), and considers this in the context of life-history trade-offs, and, ultimately, lifetime reproductive success.
Recommended Citation
Lynn, Sharon E. and Benowitz-Fredericks, Z Morgan, "Glucocorticoids, environmental challenges, and reproduction in birds" (2024). Faculty Contributions to Books. 330.
https://digitalcommons.bucknell.edu/fac_books/330
