Kin discrimination in cooperatively breeding long-tailed tits

Long-tailed tits Aegithalos caudatus are cooperative breeders ih which help ers exhibit a kin preference in their cooperative behaviour. We investigate d the mechanism through which this preference is achieved by first conducti ng an experiment for testing whether breeders could recognize the calls of their relatives while controlling for spatial effects. We found that there were significant differences in the responses of breeders to the vocalizati ons of kill and non-kin, suggesting that vocal cues may be used for kin rec ognition. We conducted a second experiment in order to investigate whether recognition is achieved on the basis of relatedness pel se or through assoc iation, Nestlings were cross-fostered between unrelated broods in order to create broods composed of true and foster siblings. In subsequent years, su rvivors from experimental broods did not discriminate between true and fost ered siblings when making helping decisions, indicating that recognition is learned and not genetically determined. We discuss the effectiveness of le arning through association as an indirect cue to kinship.