2000OlssonetalProcRSoc.pdf (179.07 kB)
Testosterone, ticks and travels: a test of the immunocompetence-handicap hypothesis in free-ranging male sand lizards
journal contribution
posted on 2023-05-16, 12:36 authored by Olsson, M, Erik WapstraErik Wapstra, Madsen, T, Silverin, BThe immunocompetence-handicap hypothesis suggests that androgen-dependent male characters constitute honest signals of mate and/or rival quality because of the imposed costs through immune suppression associated with elevated testosterone levels. We demonstrate in a field experiment that male sand lizards (Lacerta agilis) exposed to elevated testosterone suffered from increased mass loss and tick load compared to control males. Although the first of these two results could be due to an elevated basal metabolic rate from increased plasma testosterone levels, the increased parasite load was statistically independent of the loss in body condition and is likely to be due to compromised immune function. Testosterone-treated males showed greater mobility than control males, and greater mobility resulted in higher mating success. Our experiment thus lends support to the immunocompetence-handicap hypothesis, suggesting that male testosterone levels have been moderated by balancing selection for reproductive success and sustained immune function.
History
Publication title
Royal Society of London. Proceedings. Series B - Biological SciencesVolume
267Issue
1459Pagination
2339-2343ISSN
0962-8452Department/School
School of Natural SciencesPublisher
Royal Soc LondonPlace of publication
6 Carlton House Terrace, London, England, Sw1Y 5AgRepository Status
- Restricted