Stress Response and the Value of Reproduction: Are Birds Prudent Parents?

• Published in: The American naturalist Vol. 173; no. 5; pp. 589 - 598
• Main Authors: Bókony, Veronika, Lendvai, Ádám Z., Liker, András, Angelier, Frédéric, Wingfield, John C., Chastel, Olivier
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01-05-2009; University of Chicago Press; University of Chicago, acting through its Press
• Subjects: Animal and plant ecology; Animal reproduction; Animal, plant and microbial ecology; Animals; Aves; Biodiversity and Ecology; Biological and medical sciences; Biological Evolution; Birds; Birds - physiology; Breeding; Comparative analysis; Corticosterone - blood; Environment and Society; Environmental Sciences; Female; Female animals; Fundamental and applied biological sciences. Psychology; General aspects; Global Changes; Hormones; Male; Male animals; Modeling; Nesting Behavior - physiology; Phylogenetics; Phylogeny; Predation; Reproduction; Sex Characteristics; Sex linked differences; Sexual reproduction; Stress; Stress response; Stress, Physiological; Survival analysis; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; comparative method; brood value; evolution; corticosterone; birds; life history; Life history; Corticosterone; Parent; Method; Glucocorticoid; Stress; Vertebrata; Reproduction; Adrenal hormone; Aves
• ISSN: 0003-0147; 1537-5323
• DOI: 10.1086/597610

In vertebrates, stressors such as starvation or predator attacks stimulate the rapid elevation of circulating glucocorticoid hormones, triggering physiological and behavioral responses that aid immediate survival but simultaneously inhibit reproduction. This stress response has been proposed to serve as a physiological mediator of life‐history trade‐offs: when the value of current reproduction is high relative to the value of future reproduction and survival, a mitigated stress response is expected to enable successful breeding and maximize fitness. Using phylogenetic comparative analyses, we investigated baseline and peak stress‐induced plasma corticosterone levels during parental care in 64 bird species. We found that (1) species with a higher value of the current brood relative to future breeding mounted weaker corticosterone responses during acute stress, and (2) females in species with more female‐biased parental care had weaker corticosterone responses. These results support the brood value hypothesis, suggesting that the stress response evolves as an adaptive basis for life‐history strategies. Further, we found that (3) baseline corticosterone correlated positively with brood value and negatively with body mass, and (4) peak corticosterone was greater in species breeding at higher latitudes. The latter findings suggest that circulating corticosterone concentrations might be matched to the anticipated demands and risks during nesting.