Naturwissenschaften

, Volume 94, Issue 11, pp 895–902

Carotenoids, immune response and the expression of sexual ornaments in male greenfinches (Carduelis chloris)

Authors

    • Department of Evolutionary BiologyEstación Biológica de Doñana, CSIC
  • Juan A. Amat
    • Department of Evolutionary BiologyEstación Biológica de Doñana, CSIC
Original Paper

DOI: 10.1007/s00114-007-0268-5

Cite this article as:
Aguilera, E. & Amat, J.A. Naturwissenschaften (2007) 94: 895. doi:10.1007/s00114-007-0268-5

Abstract

Allocation trade-offs of carotenoids between their use in the immune system and production of sexual ornaments have been suggested as a proximate mechanism maintaining honesty of sexual signals. To test this idea, we experimentally examined whether carotenoid availability in the diet was related to variation in antibody response to novel antigens in male greenfinches (Carduelis chloris aurantiiventris), a species with extensive carotenoid-dependent plumage colouration. We also measured the cost of mounting a humoral response in terms of circulating carotenoids. Finally, we examined the relationship between plumage colour, immune response and circulating carotenoids. We found that males with carotenoid-supplemented diets showed stronger antibody response than non-supplemented birds. We also found that activation of the immune system significantly reduced circulating carotenoids (24.9% lower in immune-challenged birds than in control birds). Finally, intensity (chroma) of ventral plumage colouration of males, a character directly related to concentration of total carotenoids in feathers, was negatively correlated with the immune response and circulating carotenoids in winter. These results support the idea that carotenoids are a limiting resource and that males trade ornamental colouration against immune response.

Keywords

Sexual selectionImmune responseCarotenoidsPlumage colour

Copyright information

© Springer-Verlag 2007