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Dancing with the ugliest: females mated with unattractive males are more stressed

Mate choice is a complex process. Females dream with their own “Prince Charming”, but their expectations are often disappointed… and this may have serious impacts in the organism. In a recent study performed in the red grouse (Lagopus lagopus scoticus) we show that females mated with the most attractive males (i.e. those displaying the biggest supraorbital combs) showed lower levels of corticosterone in their feathers. Corticosterone is a key hormone released during stress responses, so this result indicates that these females mated with the less attractive males were more stressed than those mated with the most “popular boys” of the population. We also performed an experimental manipulation of the level of infection by an intestinal parasite nematode (Trichostrongylus tenuis) in females. We found that, when suffering an infection, those females mated with the less attractive males showed higher levels of corticosterone than those mated with highly ornamented males. That is, the attractiveness of the mate influenced the stress level experienced by the female during the infection.

These results contribute to better inderstanding the costs and benefits associated to mate choice, establishing a link between mating constraints, health and stress.

The results of this study have been published in the journal Behavioral Ecology and Sociobiology, within an article signed by Francois Mougeot, Adam Lendvai, Jesús Martínez-Padilla, Lorenzo Pérez-Rodríguez, Mathieu Giraudeau, Fabián Casas, Ignacio T. Moore and Steve M. Redpath, entitled " Parasites, mate attractiveness and female feather corticosterone levels in a socially monogamous bird". The PDF of this paper is available on the left-side panel of this page.



  • Female red grouse (Picture: Lorenzo Pérez-Rodríguez)
  • Trying to arrive to our study site at Edinglassie (Picture: Lorenzo Pérez-Rodríguez)
  • One of the moors included in the study (Picture: Lorenzo Pérez-Rodríguez)
  • Grouse catching was often a hard (and wet) job (Picture: Lorenzo Pérez-Rodríguez)
  • Pair of red grouse (Picture: Rocio Tarjuelo)