Sperm whales produce rhythmic patterns of clicks when they are resting or socializing at the surface. These clicks are much shorter than dolphin whistles and have a much broader frequency. They sound very similar to a loud human handclap. The click patterns are called codas, and it is thought that each sperm whale has its own individually distinctive coda pattern. It is common to hear whales exchange codas during social behaviors.
This is a recording of sperm whale codas. The sound clip contains the same coda used three times in succession by a single sperm whale off Hawaii. The spectrogram shows the patterned sets of clicks that make up the coda. Note the timing of the click sequence within a single coda - the interval of time between the first and second clicks is longer than the time between the second and third click. The timing of the clicks in the sequence is what makes each coda pattern unique.
Click either choice below to hear the sperm whale coda sound:
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Sound courtesy of Mark McDonald and National Marine Fisheries Service.
Seals and sea lions that breed in colonies have also developed a form of communication that uses individually distinctive vocalizations to reunite mom and pup when the moms return to the crowded colony after feeding. A mother will give a pup-attraction call when she returns. Her calls are heard by her pup and are often returned with calls from the pup. Both mother and pup recognize each other's vocalizations, which allow them to find each other in a very crowded rookery. The vocalizations produced by seals and sea lions on land sound like deep roars.
Click either choice below to hear sea lions:
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Courtesy of Jennifer Miksis, University of Rhode Island
This is a recording of California sea lions. Note that the maximum frequency (4 kHz) of the sea lion vocalizations are much lower than the minimum frequency of the dolphins whistles in the spectrogram above (7 kHz).
