Male signalling and dominance in the Penduline Tit Remiz pendulinus

Secondary sexual characters (e.g. badges, ornaments) are involved in many species in male-male competition and/or in female choice. We tested a proposition, the armament-ornament model, in a small passerine bird, the Eurasian penduline tit Remiz pendulinus, which exhibits an unusually diverse breeding system that includes sequential polygyny and polyandry, and uniparental care by the male or the female. Previous studies showed that the size of black eye-stripes (masks) in males functions as an ornament, since females prefer males with large masks. Here we report that in an aviary experiment, male mask size did not predict dominance status. Our results are consistent with a field study, and these together suggest that male mask size is a secondary sexual signal in penduline tits: it is a trait used by females in mate choice decisions.