Recognition of Parents' Voices by Young Cliff Swallows

Abstract

Abstract Cliff Swallow (Hirundo pyrrhonota) chicks were played calls of parents and unrelated (control) adults at 9 and 18 days of age. Younger chicks showed no difference in the frequency of their antiphonal begging calls to parental vs. control calls. The older, near-fledging chicks, however, responded significantly more to parental calls than to control calls: 78% of their total antiphonal calls were in response to parental playback calls. In these older chicks, the degree of preference correlated with the measured acoustic differences between the parent and control calls. The results indicate that Cliff Swallow chicks are able to recognize their parents by voice before they leave the nest. Offspring recognition of parents is discussed as it relates to the evolution of parent-offspring recognition systems in general.