SOCIAL INHIBITION OF SONG IMITATION AMONG SIBLING MALE ZEBRA FINCHES

A male zebra finch, Taeniopygia guttata, kept with its father until ad ulthood develops an imitation of its father's song motif, We report he re that the completeness of this imitation was sensitive to the social or auditory context in which the bird grew up: the greeter the number of male siblings in a clutch, the shorter the mean duration of the so ng motif and the fewer the mean number of song notes imitated from the father; the latter shortfall was not compensated by other, improvised notes. We call this effect fraternal inhibition, Fraternal inhibition was avoided by members of a clutch that developed the song first. To our surprise, this role commonly fell to one of the younger birds in t he clutch, Early song learning may influence fitness since individuals that produced the most complete imitations also tended to induce more egg laying.