On the ability of crested terns, Sterna bergii, to recongnize their own chicks.

Abstract

Exchange experiments carried out between nestlings of the crested tern, Sterna bergii, on Montagu I., N.S.W., indicate that while parents do not recognize their own eggs or newly hatched chicks individually, they have learnt to recognize their own chicks by the time they are 2 days old. Comparison of these results with those obtained in other Laridae suggests that the ability of the parents to distinguish their own chick appears shortly before the latter begins to wander from the nest. A sound spectrograph study of the calls of the chicks showed some inter-individual variation, but also much intra-individual variation. The value of the chick's voice as a recognition character therefore remains uncertain.