PARENT-OFFSPRING RECOGNITION IN TREE SWALLOWS, TACHYCINETA BICOLOR

Parent-offspring recognition appears to be highly developed in species in which the risk of misdirecting care is high (e.g. colonial species ). Some of the best evidence for this relationship comes from comparat ive work on swallows of the family Hirundinidae. Using methods followe d in earlier studies, we determined whether parent-offspring recogniti on occurs in the tree swallow, Tachycineta bicolor, a non-colonial spe cies closely related to the highly colonial bank swallow, Riparia ripa ria, and the solitary rough-winged swallow, Stelgidopteryx ruficollis. Parents did not discriminate between playbacks of the calls of their own versus non-related nestlings. However, older nestlings called more in response to playback of parental calls than non-parental calls, su ggesting that they recognized their own parents. Despite significant i ndividual variation in parental and nestling calls, variation in tree swallow nestling calls was lower than analogous calls in the bank swal low. Our results provide further support for a positive relationship b etween recognition, individual variation in call structure and colonia lity. (C) 1997 The Association for the Study of Animal Behaviour.