Mate choice in the Grey partridge (Perdix perdix): role of male physical and behavioural traits

The brown breast patch of the male grey partridge, the species’ most conspicuous sexually dimorphic trait, was totally or partly bleached out, to test its influence on female preference. In mate-choice experiments, patch size (which was unaVected by early testosterone treatment) appeared to be unimportant: artificially and naturally bred females primarily selected males on the basis of their vocal performance. High rates of rusty-gate calls and certain features of their acoustic structure, usually undervalued in studies on non-oscine birds, were the main determinants of male success, with the morphological traits being of lesser importance.