Dr. Hal Whitehead is one of the great modern experts on sperm whales (Physeter macrocephalus) and has studied sound patterns in the communication of these marine mammals. He found and listened to four different click types: usual clicks, creaks, coda sequences, and the mysterious slow clicks or clangs. As Philip Hoares reports in his book “The Whale” :
Dr Whitehead organizes the sperm whale's clicks into four functional groupings: usual clicks, about two a second, made by foraging whales; creaks, a regular, more rapid succession of clicks which he describes as sounding like the rusty hinge on an opening door, and which indicate a whale homing in on its prey, or scanning other whales at the surface; the communicative sequence of codas - such as click-click-click-pause-click - a kind of cetacean Morse code which suggests ‘conversations’, although ‘we do not know what information is being transmitted’. Most mysterious of all are the slow clicks or clangs made by mature males and which Whitehead compares to ‘a jailhouse door being slammed every seven seconds’.
Sounds a bit like whale watching from Alcatraz Island.
Keywords: cetology, research, underwater sounds, sonar, communication, code decryption
[1 ] Philip Hoare: The Whale • In Search of the Giants of the Sea. HarperCollins Publishers, New York, 2010; pages 76, 77 and357.