Parasites , testosterone and honest carotenoid-based signalling of health

  title={Parasites , testosterone and honest carotenoid-based signalling of health},
  author={François Mougeot and Lorenzo P{\'e}rez-Rodr{\'i}guez and Jes{\'u}s Mart{\'i}nez-Padilla and Fiona Leckie and Steve Redpath},
1. Among the commonest sexual signals of birds are the red-yellow traits pigmented by carotenoids, but how they reliably advertise individual quality remain poorly understood. Here we tested the hypothesis that carotenoid-based signalling is enhanced by testosterone but reduced by parasites, and that the dual action of testosterone on ornament expression and parasite resistance ensures reliable signalling. 2. Tetraonid birds such as the red grouse Lagopus lagopus scoticus have bright red combs… CONTINUE READING