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Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine

Organisms continuously face environmental fluctuations, and allocation of metabolic investment to meet changing energetic demands is fundamental to survival and reproductive success. Glucocorticoid (GC) hormones (e.g., corticosterone [CORT]) play an important role in energy acquisition and allocatio...

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Autores principales: Jimeno, Blanca, Prichard, Mackenzie R, Landry, Devin, Wolf, Cole, Larkin, Beau, Cheviron, Zachary, Breuner, Creagh
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7794023/
https://www.ncbi.nlm.nih.gov/pubmed/33791569
http://dx.doi.org/10.1093/iob/obaa030
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author Jimeno, Blanca
Prichard, Mackenzie R
Landry, Devin
Wolf, Cole
Larkin, Beau
Cheviron, Zachary
Breuner, Creagh
author_facet Jimeno, Blanca
Prichard, Mackenzie R
Landry, Devin
Wolf, Cole
Larkin, Beau
Cheviron, Zachary
Breuner, Creagh
author_sort Jimeno, Blanca
collection PubMed
description Organisms continuously face environmental fluctuations, and allocation of metabolic investment to meet changing energetic demands is fundamental to survival and reproductive success. Glucocorticoid (GC) hormones (e.g., corticosterone [CORT]) play an important role in energy acquisition and allocation in the face of environmental challenges, partly through mediation of energy metabolism. Although GCs and metabolic rate are expected to covary, surprisingly few empirical studies have demonstrated such relationships, especially in wild animals. Moreover, studies testing for associations between GCs and fitness generally do not account for among-individual differences in energy expenditure or energy allocation. We measured CORT (baseline and stress-induced) and metabolic traits (resting metabolic rate [RMR], cold-induced VO(2max) [M(sum)], and aerobic scope [the difference between M(sum) and RMR]) in female tree swallows (Tachycineta bicolor) during chick-rearing, and tested for their associations with several variables of reproductive performance. We found a positive relationship between RMR and baseline CORT, but no consistent associations between stress-induced CORT (SI-CORT) and M(sum). This suggests that while baseline CORT may be a good indicator of an individual’s baseline metabolic investment, SI-CORT responses are not associated with aerobic scope or the upper limits of aerobic performance. Furthermore, we found that metabolic traits were associated with reproductive performance: females with higher reproductive output showed higher M(sum), and also tended to show higher RMR. Overall, these results suggest that metabolic traits are better predictors of reproductive output in tree swallows than CORT concentrations. They further point to the maximal aerobic capacity being higher in females investing more heavily in a current reproductive event, but whether this association reflects trade-offs between current and future reproductive efforts remains to be tested.
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spelling pubmed-77940232021-03-30 Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine Jimeno, Blanca Prichard, Mackenzie R Landry, Devin Wolf, Cole Larkin, Beau Cheviron, Zachary Breuner, Creagh Integr Org Biol Research Article Organisms continuously face environmental fluctuations, and allocation of metabolic investment to meet changing energetic demands is fundamental to survival and reproductive success. Glucocorticoid (GC) hormones (e.g., corticosterone [CORT]) play an important role in energy acquisition and allocation in the face of environmental challenges, partly through mediation of energy metabolism. Although GCs and metabolic rate are expected to covary, surprisingly few empirical studies have demonstrated such relationships, especially in wild animals. Moreover, studies testing for associations between GCs and fitness generally do not account for among-individual differences in energy expenditure or energy allocation. We measured CORT (baseline and stress-induced) and metabolic traits (resting metabolic rate [RMR], cold-induced VO(2max) [M(sum)], and aerobic scope [the difference between M(sum) and RMR]) in female tree swallows (Tachycineta bicolor) during chick-rearing, and tested for their associations with several variables of reproductive performance. We found a positive relationship between RMR and baseline CORT, but no consistent associations between stress-induced CORT (SI-CORT) and M(sum). This suggests that while baseline CORT may be a good indicator of an individual’s baseline metabolic investment, SI-CORT responses are not associated with aerobic scope or the upper limits of aerobic performance. Furthermore, we found that metabolic traits were associated with reproductive performance: females with higher reproductive output showed higher M(sum), and also tended to show higher RMR. Overall, these results suggest that metabolic traits are better predictors of reproductive output in tree swallows than CORT concentrations. They further point to the maximal aerobic capacity being higher in females investing more heavily in a current reproductive event, but whether this association reflects trade-offs between current and future reproductive efforts remains to be tested. Oxford University Press 2020-10-14 /pmc/articles/PMC7794023/ /pubmed/33791569 http://dx.doi.org/10.1093/iob/obaa030 Text en © The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Jimeno, Blanca
Prichard, Mackenzie R
Landry, Devin
Wolf, Cole
Larkin, Beau
Cheviron, Zachary
Breuner, Creagh
Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine
title Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine
title_full Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine
title_fullStr Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine
title_full_unstemmed Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine
title_short Metabolic Rates Predict Baseline Corticosterone and Reproductive Output in a Free-Living Passerine
title_sort metabolic rates predict baseline corticosterone and reproductive output in a free-living passerine
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7794023/
https://www.ncbi.nlm.nih.gov/pubmed/33791569
http://dx.doi.org/10.1093/iob/obaa030
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