Kin recognition: function and mechanism in avian societies

Cooperative behaviour resulting from kin selection is widespread among anim als and the ability to recognize and discriminate between kin and non-kin i s a critical element in kin selection theory. Current evidence suggests tha t associative learning is the most likely mechanism of kin discrimination. However, surprisingly, there have been no experimental studies of the putat ive 'associative-learning period', the likely recognition mechanisms enabli ng fine discrimination between close and distant kin of similar familiarity , whether generic or individual cues are employed in kin recognition, and h ow recognition ability varies at different stages of a species' life histor y. Comparative studies of kin recognition and discrimination in cooperative and noncooperative species are also needed to shed light on the adaptive v alue of helping behaviour and to identify key factors in the evolution of c ooperation.