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Proc Biol Sci. May 7, 2000; 267(1446): 883–889.
PMCID: PMC1690613
Testosterone treatment is immunosuppressive in superb fairy-wrens, yet free-living males with high testosterone are more immunocompetent.
A Peters
Division of Botany and Zoology, Australian National University, Canberra ACT.
A Peters: anne.peters/at/
The immunocompetence handicap hypothesis proposes that the immunosuppressive effect of testosterone enforces honesty of sexual signalling via a physiological trade-off between signal intensity and immunocompetence. However, evidence that testosterone is immunosuppressive is scant, particularly in birds. I studied the correlation between immunocompetence and testosterone in superb fairy-wrens (Malurus cyaneus), a species with intense intersexual selection. Males are seasonally dichromatic and testosterone increases during the moult from dull brown eclipse plumage into bright nuptial plumage. I determined the primary antibody response to immunization with sheep red blood cells (SRBCs) in (i) control and testosterone-implanted males in captivity, and (ii) a cross-section of free-living males with basal and elevated testosterone (in eclipse plumage, moulting and in nuptial plumage). Experimental treatment with testosterone decreased the likelihood of an antibody response to SRBCs in captive birds. In contrast, free-living males which had acquired the nuptial plumage and had naturally elevated testosterone were more likely to respond to SRBCs than males in eclipse plumage with basal testosterone levels. The association between higher immunocompetence and higher immunosuppressive testosterone could arise if both are positively correlated with male phenotypic quality In addition, the association could result if males compensate for potential immunosuppression by enhancing their humoral immune responses, particularly since high testosterone is linked to other demanding activities such as moulting and courtship displays.
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Selected References
These references are in PubMed. This may not be the complete list of references from this article.
  • Deerenberg C, Arpanius V, Daan S, Bos N. Reproductive effort decreases antibody responsiveness. Proc Biol Sci. 1997 Jul 22;264(1384):1021–1029. [PMC free article]
  • Nordling D, Andersson M, Zohari S, Gustafsson L. Reproductive effort reduces specific immune response and parasite resistance. Proc Biol Sci. 1998 Jul 22;265(1403):1291–1298. [PMC free article]
  • Westneat DF, Birkhead TR. Alternative hypotheses linking the immune system and mate choice for good genes. Proc Biol Sci. 1998 Jun 22;265(1401):1065–1073. [PMC free article]
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