Immune function, signals and hormones

In the 1990s we conducted the first experiments to test the immuno-competence handicap hypothesis. Working on house sparrows we demonstrated that testosterone did influence bib size - but only in adult birds, not in juveniles. We also provided the first evidence that testosterone did influence immune function but not directly as claimed by Folstad and Karter but indirectly via corticosterone. It was this result that led us to produce the selected lines of zebra finch to allow experimental discrimination between the effects of testosterone and corticosterone. It is the gene expression changes in these birds that we are looking at with microarrays.

Roberts, M. L., Buchanan, K. L. & Evans, M. R. 2004. Testing the Immunocompetence Handicap Hypothesis: A review of the evidence. Animal Behaviour 68, 227-239. doi:10.1016/j.anbehav.2004.05.001.

Buchanan, K.L., Evans, M.R. & Goldsmith 2003. Testosterone, dominance signalling and immunosuppression in the house sparrow, Passer domesticus. Behavioral Ecology and Sociobiology 55, 50-59. doi: 10.1007/s00265-003-0682-4

Buchanan, K.L., Evans, M.R., Goldsmith, A.R., Bryant, D.M. & Rowe, L.V. 2001. Testosterone influences basal metabolic rate in male house sparrows: a new cost of dominance signalling? Proceedings of the Royal Society London Series B 268, 1337-1344. 

Poiani, A., Goldsmith, A.R. & Evans, M.R. 2000. Ectoparasites of house sparrows (Passer domesticus): an experimental test of the immunocompetence handicap hypothesis. Behavioral Ecology and Sociobiology 47: 230-242

Norris, K.J. & Evans, M.R. 2000. Ecological immunity: life history trade-offs and immune defence in birds. Behavioral Ecology 11: 19-26. doi: 10.1093/beheco/11.1.19

Evans, M.R., Goldsmith A.R. & Norris, S.R.A. 2000. Testosterone influences bib size and antibody production in house sparrows as predicted by the immuno-competence handicap hypothesis. Behavioral Ecology and Sociobiology 47: 156-163. doi: 10.1007/s002650050006 .

© Matthew Evans 2015