Sexual dimorphism in immunocompetence: what does life-history theory predict?

Andrew M. Stoehr and Hanna Kokko

Behavioral Ecology, 2006, vol. 17, issue 5, 751-756

Abstract: Sexual dimorphism in immunocompetence, usually in the direction of inferior male immunocompetence, has historically been explained as the result of proximate physiological mechanisms such as the immunosuppressive effects of the male hormone testosterone. More recently, it has been argued that this pattern is best understood as a result of resource-based trade-offs between male mating effort and immune defense, a trade-off that females do not make. The central prediction of this hypothesis is that as the strength of sexual selection on males increases, the magnitude of the sex differences in immunocompetence will increase. Two implicit assumptions of this argument are that 1) longevity is of more importance for female than for male fitness and 2) that the primary benefit of immunocompetence is increased longevity. However, both of these assumptions may not be as broadly applicable as has been argued. We have modeled the optimal allocation to immunocompetence for males and females without making these assumptions. We find that the optimal allocation to immune defense for males decreases as the strength of sexual selection increases, as predicted. However, males may still invest more, relative to females, into immunocompetence if the impact of parasites on condition differs for the sexes and/or if the relationship between condition and reproduction differs for the sexes. We argue that these previously overlooked assumptions may be critical for predicting sex-specific patterns of immunocompetence. Copyright 2006.

Keywords: ecological immunology; immune defense; life-history theory; sexual selection (search for similar items in EconPapers)
Date: 2006
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/ark018 (application/pdf)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:oup:beheco:v:17:y:2006:i:5:p:751-756

Ordering information: This journal article can be ordered from
https://academic.oup.com/journals

Access Statistics for this article

Behavioral Ecology is currently edited by Louise Barrett

More articles in Behavioral Ecology from International Society for Behavioral Ecology Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK.
Bibliographic data for series maintained by Oxford University Press ().