Africa is increasingly popular as a destination to see whales, especially off the east and southern coasts. But how do they communicate? Mike Unwin listens beneath the ocean waves to understand how they talk to each other.
Land mammals such as lion, cheetah and elephant are known to communicate with a series of growls, purrs and snorts. Down in the depths of the ocean, whales produce a remarkable range of sounds, which they use in both feeding and communication. Best known are the long, haunting ‘songs’ of humpback whales and other baleen whales, which may carry for hundreds of kilometres underwater and serve in sexual selection.
Studies have shown that these calls comprise of a complex pattern of learned phrases that are specific both to individuals and to geographical areas. Dolphins and other toothed whales produce rapid bursts of high-frequency clicks – generated through a passage in the head known as the ‘phonic lips’ – that bounce off other objects and, in a process called echolocation, allow them to find and identify prey underwater. Sperm whales and beaked whales can stun and even kill prey with the force of these click streams. Toothed whales also produce whistles to communicate with one another.
All cetaceans depend upon their powerful hearing in order to feed and communicate; conservationists worry that the volume of ambient shipping noise in today’s oceans is causing the creatures serious problems and may explain the regular mass-stranding of disoriented pilot whales and other species.
Learn more about cetaceans in issue 81 of the print edition of Travel Africa by clicking here.