[Behavioral and acoustical characteristics of the reproductive gathering of beluga whales (Delphinapterus leucas) in the vicinity of Myagostrov, Golyi Sosnovets, and Roganka Islands (Onega Bay, the White Sea)].

The structure of the summer reproductive gathering of beluga whales Delphinapterus leucas was studied in the vicinity of Myagostrov, Golyi Sosnovets, and Roganka islands (Onega Bay, the White Sea) in 2006 and 2008. The abundance, age and sex structure, behavior, and swimming and acoustic behavior were studied in detail.

[Individual patterns of tonal (whistling) signals of bottlenose dolphins (Tursiops truncates) kept in relative isolation].

The results of study of the subaqueous acoustic signaling of bottlenose dolphins (Tursiopsis truncatus) in a dolphinarium are shown. Individual patterns of whistling signals of four individuals were described and analyzed. To determine which animal produced the sound, the method of "relative isolation" was used. It was found that the pattern included whistles specific for a particular individual ("signature whistles"). The percentage of these whistles in the patterns varied considerably among individuals. The signatures had variable frequency and duration. The phenomenon of "imitation" was typical for animals at higher positions in the hierarchy: generating "signatures" specific for other individuals. Besides the signatures, variable signals and whistles with simple frequency contours were found in the patterns.