Abstract
Mate choice is expected to be important for the fitness of both sexes for species in which successful reproduction relies strongly on shared and substantial parental investment by males and females. Reciprocal selection may then favour the evolution of morphological signals providing mutual information on the condition/quality of tentative partners. However, because males and females often have differing physiological constraints, it is unclear which proximate physiological pathways guarantee the honesty of male and female signals in similarly ornamented species. We used the monomorphic king penguin (Aptenodytes patagonicus) as a model to investigate the physiological qualities signalled by colour and morphological ornaments known to be under sexual selection (coloration of the beak spots and size of auricular feather patches). In both sexes of this slow-breeding seabird, we investigated the links between ornaments and multiple indices of individual quality; including body condition, immunity, stress and energy status. In both sexes, individual innate immunity, resting metabolic rate, and the ability to mount a stress response in answer to an acute disturbance (capture) were similarly signalled by various aspects of beak coloration or auricular patch size. However, we also reveal interesting and contrasting relationships between males and females in how ornaments may signal individual quality. Body condition and oxidative stress status were signalled by beak coloration, although in opposite directions for the sexes. Over an exhaustive set of physiological variables, several suggestive patterns indicated the conveyance of honest information about mate quality in this monomorphic species. However, sex-specific patterns suggested that monomorphic ornaments may signal different information concerning body mass and oxidative balance of males and females, at least in king penguins.
Original language | English |
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Pages (from-to) | 200-214 |
Number of pages | 15 |
Journal | Biological Journal of the Linnean Society |
Volume | 118 |
Issue number | 2 |
Early online date | 21 Dec 2015 |
DOIs | |
Publication status | Published - Jun 2016 |
Bibliographical note
AcknowledgementsWe thank G.E. Hill for helpful discussion on the analyses, and F. Criscuolo for help with field and laboratory work and insightful comments on the manuscript. We are grateful S. Calhim, I. Keddar and two anonymous reviewers for insightful comments on the analyses and on previous versions of the paper. L. Cattin and L. Bovet helped with preliminary data analyses. S. Reichert and S. Massemin-Challet helped with oxidative stress analyses. The research was funded by the French Polar Institute (IPEV–Research Program 119) and the French National Centre for Scientific Research (CNRS-INEE). Field logistic support was provided by Terres Australes et Antarctiques Françaises. VAV was funded by a post-doctoral fellowship from the Fondation Fyssen.
Keywords
- body condition
- king penguin
- monomorphic seabird
- mutual mate choice
- ornament
- oxidative stress
- sexual selection
- ultra-violet signals
- history trade-offs
- mate choice
- Aptenodytes-Patagonicus
- American goldfinches
- plumage coloration
- immune function
- bill color