We investigate how variation in breeding plumes influences pairing patterns, extra-pair copulations and breeding performance in the colonial cattle egret (Bubulcus ibis ibis). The breeding plumes of both male and female cattle egrets varied from almost none, to lush head, back and scapular plumes. Overall, male breeding plumes were longer and darker than those of females, but we observed the full range of plume development in both sexes. Plume development was positively correlated within breeding pairs. Females may be more selective in mate choice since they only paired with males with similar or better plumes and only accepted extra-pair copulations when the male had plumes that were greater than or equal to those of their mates. Males, in contrast frequently paired with females of lower plume development, and did not target well plumed females for extra pair copulations. Females may obtain direct benefits from pairing with well plumed males since these males copulated and fed chicks at a higher rate, although this did not lead to higher fledging success in our study. Well plumed females did not have higher nest attendance, nestling attendance, feeding rates or fledging success. Nevertheless, males appeared to invest more in a breeding attempt when paired to a well plumed female by increasing copulation rates, mate attendance and nest site attendance. Breeding plumes may therefore signal both parental and genetic quality to prospective mates.