An experimental test of the effect of brood size on glucocorticoid responses, parental investment, and offspring phenotype
Autor: | Joanna K. Hubbard, Sara A. Kaiser, Maren N. Vitousek, Rebecca J. Safran, Brittany D. Jenkins |
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Rok vydání: | 2017 |
Předmět: |
0106 biological sciences
0301 basic medicine medicine.medical_specialty Offspring media_common.quotation_subject Zoology Models Biological 010603 evolutionary biology 01 natural sciences Nesting Behavior 03 medical and health sciences chemistry.chemical_compound Endocrinology Corticosterone Internal medicine medicine Hirundo Animals Parental investment Glucocorticoids reproductive and urinary physiology media_common biology Reproductive success Body Weight fungi biology.organism_classification Brood Phenotype 030104 developmental biology chemistry Swallows behavior and behavior mechanisms Female Animal Science and Zoology Reproduction Glucocorticoid medicine.drug |
Zdroj: | General and Comparative Endocrinology. 247:97-106 |
ISSN: | 0016-6480 |
Popis: | Because elevated glucocorticoid levels can impair reproduction, populations or species that engage in particularly valuable reproductive attempts may down-regulate the glucocorticoid stress response during reproduction (the brood value hypothesis). It is not clear, however, whether individuals rapidly modulate glucocorticoid responses based on shifting cues about the likelihood of reproductive success. By manipulating brood size to create broods that differed in potential value, we tested whether female barn swallows (Hirundo rustica) rapidly modulated the glucocorticoid stress response to promote investment in high-value broods, and whether nestling phenotype was influenced by treatment. Within-individual changes in female corticosterone, body mass, and measures of oxidative stress were unrelated to brood size treatment. Standard offspring provisioning rate did not differ across treatments; however, in the presence of a model predator, females raising enlarged broods maintained higher offspring feeding rates relative to control broods. Brood size did influence nestling phenotype. Nestlings from enlarged broods had lower body mass and higher baseline corticosterone than those from reduced broods. Finally, in adult females both baseline and stress-induced corticosterone were individually repeatable. Thus, while under moderately challenging environmental conditions brood size manipulations had context-dependent effects on parental investment, and influenced nestling phenotype, maternal glucocorticoid levels were not modulated based on brood value but were individually consistent features of phenotype during breeding. |
Databáze: | OpenAIRE |
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