Age of male is an important cue in mate selection, including extra-pair copulations; different phenotypic and behavioural traits are known to be age related. Paternity studies show that older males predominate as fathers of extra-pair young. It remains unclear if females actively choose older males because they possess high quality traits or because older males are more successful in coercing fertile females. We experimentally provided mounted males of different age (yearling vs. adult) of great grey shrike Lanius excubitor with nuptial gifts of different quality (vole vs. cricket) and observed reactions of females and their social partners. Females strongly preferred older males with energy-rich nuptial gifts. The reactions of females’ social partner to the extra-pair male did not differ significantly amongst experimental groups. However, males responded to the reaction of their mates and male aggressive behaviour increased when their mate showed an interest in an intruder
