Baseline glucocorticoids alone do not predict reproductive success across years, but in interaction with enzymatic antioxidants

© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd..

Glucocorticoids are known to adjust organismal functions, such as metabolism, in response to environmental conditions. Therefore, these hormones are thought to play a key role in regulating the metabolically demanding aspects of reproduction, especially in variable environments. However, support for the hypothesis that variation in glucocorticoid concentrations predicts reproductive success is decidedly mixed. Two explanations may account for this discrepancy: (i) Glucocorticoids might not act independently but could interact with other physiological traits, jointly influencing reproduction, and (ii) such an association could become apparent primarily in challenging environments when glucocorticoid concentrations increase. To address these two possibilities, we determined natural variation in circulating baseline glucocorticoid concentrations in parental great tits (Parus major) alongside two physiological systems known to be related with an individual's metabolism: oxidative status parameters (i.e., concentrations of pro-oxidants, dietary, and enzymatic antioxidants) and body condition. These systems interact with glucocorticoids and can also influence reproductive success. We measured these variables in two breeding seasons that differed in environmental conditions. When accounting for the interaction of baseline glucocorticoids with other physiological traits, we found a positive relationship between baseline glucocorticoids and the number of fledglings in adult great tits. The strength of this relationship was more pronounced for those individuals who also had high concentrations of the enzymatic antioxidant glutathione peroxidase. When studied independently, glucocorticoids were not related to fitness proxies, even in the year with more challenging environmental conditions. Together, our study lend to support the hypothesis that glucocorticoids do not influence fitness alone, but in association with other physiological systems.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:14

Enthalten in:

Ecology and evolution - 14(2024), 4 vom: 19. Apr., Seite e11193

Sprache:

Englisch

Beteiligte Personen:

Mentesana, Lucia [VerfasserIn]
Casagrande, Stefania [VerfasserIn]
Hau, Michaela [VerfasserIn]

Links:

Volltext

Themen:

Body condition
Corticosterone
Fitness
Glucocorticoids
Journal Article
Oxidative stress
Physiological network

Anmerkungen:

Date Revised 05.04.2024

published: Electronic-eCollection

Dryad: 10.5061/dryad.69p8cz997

Citation Status PubMed-not-MEDLINE

doi:

10.1002/ece3.11193

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370612256