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Humoral immune response in relation to senescence, sex and sexual ornamentation in the barn swallow ( Hirundo rustica )
Author(s) -
Saino N.,
Ferrari R. P.,
Romano M.,
Rubolini D.,
Møller A. P.
Publication year - 2003
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1046/j.1420-9101.2003.00616.x
Subject(s) - biology , hirundo , immunocompetence , sexual selection , zoology , barn , seasonal breeder , senescence , mate choice , natural selection , parasite hosting , ecology , immune system , immunology , mating , demography , population , genetics , civil engineering , engineering , sociology , world wide web , computer science
Performance of animals may decline with age. The effects of senescence, however, may differ between the sexes because of differences in physiology and behaviour. Acquired immunity provides hosts with efficient mechanisms of anti‐parasite defence, but the effect of senescence on immunocompetence has never been studied in natural populations. In the barn swallow ( Hirundo rustica ), primary antibody response to an antigen during one breeding season declined with age in females, while secondary response during the following breeding season declined with age in both sexes. Parasite‐mediated sexual selection theory posits that male secondary sexual characters reveal resistance to parasites. Males with large tail ornaments had stronger primary response, retained larger antibody levels until the following year, but did not differ in secondary response compared with short‐tailed males, as predicted if ornamentation reflects resistance to parasites. This is the first study showing that immunocompetence declines with age in any vertebrate under natural conditions.