Bottlenose dolphins produce individually distinctive vocalizations called signature whistles. The main objectives of Ms. Laela Sayigh's doctoral-dissertation research are to examine factors influencing the development of the signature whistle by dolphin calves, and to learn the social functions of signature and non-signature (variant) whistles. It may be possible to correlate sex differences in whistle production with the different roles males and females play in the social structure of the community. The dolphins to be studied are in a group of about 100 free- ranging bottlenose dolphins in waters near Sarasota, Florida. Data on age, sex, and matrilineal relationships are available from previous research on this group. Ms. Sayigh will observe and record undisturbed mother-calf pairs in order to study the process of whistle development directly in young calves. To test for signature-whistle recognition between mothers and older (independent) offspring, Ms. Sayigh will play back recorded whistles while dolphins are temporarily corralled in a large net. These observations should reveal whether or not the behavior of the mother contributes to a previously-observed difference in whistle development in male and female calves. The research should also elucidate the social functions of signature and variant whisles, and perhaps provide additional insights into the social relationships of bottlenose dolphins.
