REPERTOIRE AND GEOGRAPHIC-VARIATION IN UNDERWATER VOCALIZATIONS OF WEDDELL SEALS (LEPTONYCHOTES-WEDDELLII, PINNIPEDIA, PHOCIDAE) AT THE VESTFOLD HILLS, ANTARCTICA

The underwater vocalisations of Weddell seals (Leptonychotes weddellii ) near Davis, Antarctica, were many and varied. A total of 11029 vocal isations recorded throughout and immediately after the breeding season were analysed. Vocalisations were classified by cluster analysis tech niques, based on differences in frequency, duration, call shape, wavef orm and number of elements. Thirteen broad call categories (many with subdivisions) were identified. Twelve call types (belonging to nine ca tegories) made up 91.9% of the vocalisations and were present at an se ven study sites within the Vestfold Hills, and a single site at the La rsemann Hills approximately 150 km away. A further eight call types (f ive categories) made up another 6.7% of the vocalisations. These were not detected at every recording site. An additional 29 call types (11 categories) were infrequent and probably reflect the diversity of indi vidual seals. This study strengthens the case for macrogeographic vari ation in underwater Weddell seal vocalisations around Antarctica. Micr ogeographic differences, between sites within 150 km, were weak and no t consistent between sites or years. Some adult females move to differ ent breeding sites within the Vestfold Hills area between years. This would probably preclude the establishment of site specific (microgeogr aphic) repertoire differences.