Abstract: The goal of this study was to determine if Weddell seal (Leptonychotes weddellii) underwater vocalizations exhibit regional differences over mesogeographic ranges (600-2000 km). Recordings were made along the Eastern Antarctic coastline at Mawson, Davis and Casey research stations. Differences in vocalizations were examined on three levels: (1) presence of unique call types/categories. (2) rate of occurrence of call types/categories, and (3) call features (number of call elements, start frequency, frequency shift, and duration). A total of 33 different call types within 13 categories were identified. Two call types were unique to Davis and one to each of Mawson and Casey. One category was unique to Davis. Significant differences in the proportion of call usage among the three stations were found for 23 of the 26 shared call types and all 11 of the shared call categories. All call features varied among stations when compared simultaneously or individually. While differences in vocalizations were observed over the mesogeographic range, some temporal variations also were observed at two of the levels; call usage and call features. Weddell seal groups separated by >600 km exhibited different vocal patterns.
Key Words: WEDDELL SEALS; LEPTONYCHOTES WEDDELLII; UNDERWATER VOCALIZATIONS; GEOGRAPHIC VARIATIONS; TEMPORAL VARIATIONS; MESOGEOGRAPHIC RANGES.
Document Type: Research article