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Repeatable intra-individual variation in plasma testosterone concentration and its sex-specific link to aggression in a social lizard
journal contribution
posted on 2023-05-17, 03:02 authored by Geoffrey WhileGeoffrey While, Isaksson, C, Joanne McEvoyJoanne McEvoy, Sinn, DL, Komdeur, J, Erik WapstraErik Wapstra, Groothuis, TGGIndividual hormone profiles can be important generators of phenotypic variation. Despite this, work on the consequences of hormone profiles has traditionally ignored the large inter-individual variation within natural populations. However, recent research has advocated the need to explicitly consider this variation and address its consequences for selection. One of the key steps in this process is examining repeatability in hormone profiles and their links to behavioral traits under selection. In this study we show that individuals within a free-ranging population of the Australian lizard Egernia whitii exhibit temporal repeatability in their circulating baseline testosterone concentrations as well as their aggressive response towards conspecific intruders. Furthermore, we show significant, sex-specific links between testosterone and aggression. Specifically, testosterone and aggression is negatively linked in males, while there is no relationship in females. As conspecific aggression has significant consequences for fitness-related traits (parental care, mating strategies) in this species, inter-individual variation in testosterone concentrations, through their effects on aggression, could have important implications for individual fitness. We discuss the potential causes and consequences of hormonal repeatability as well as provide explanations for its sex-specific links with aggression. Specifically, we suggest that these patterns are the result of alternative hormonal pathways governing aggression within Egernia and may indicate a decoupling of aggression and testosterone across the sexes.
History
Publication title
Hormones and BehaviorVolume
58Pagination
208-213ISSN
0018-506XDepartment/School
School of Natural SciencesPublisher
Academic Press Inc Elsevier SciencePlace of publication
525 B St, Ste 1900, San Diego, USA, Ca, 92101-4495Rights statement
The definitive version is available at http://www.sciencedirect.comRepository Status
- Restricted