Detection of a unique calling pattern during the respiratory cycle of blue whale pairs
Although blue whales are known for their long (10–20 s) low-frequency (<20 Hz) vocalizations that occur in regularly patterned series, in coastal waters they produce short (1–4 s) higher-frequency (30–150 Hz) unpatterned calls just as often. Paul Thompson was among the group of scientists who first attributed these short calls to blue whales. They found the majority of these calls to be downswept in frequency but noted the presence of others that were not. This paper describes a special patterning of these non-downswept sounds that was detected in the St. Lawrence estuary in both 2000 and 2001. This patterning is variable but normally includes both regularly and irregularly spaced components. In at least a dozen cases, these mixed-pattern bouts were detected in the presence of a pair of blue whales at the surface for their respiratory cycle. Characterization of these bouts and their daily, seasonal, and spatial distributions will be presented and compared with the distributions of the short downsweeps and the long low-frequency calls. [Work supported by the Applied Research Lab ( Penn State ), NSF, and the American Museum of Natural History.]
(Berchok, C.L., Bradley, D.L., Gabrielson, T.B., and Sears, R. 2004. Detection of a unique calling pattern during the respiratory cycle of blue whale pairs. J. Acoust. Soc. Am. 116:2613. Oral Presentation.