Simplicity the key as whales change songs every few years

WHALES dispense with their signature “songs” every few years in favour of simpler tunes, marine scientists have discovered.

A study of whale song patterns spanning 13 years found the signature song of individual groups evolves gradually over time.

But every few years, a population’s song is completely replaced in an event described as a “cultural revolution”.

When it occurs, the new song is always simpler than the one that preceded it.

Humpback whales are famed for having “dialects” unique to different populations. In addition, groups of male whales have their own “anthems”, with each member of the population singing the same sequence of the same sounds.

The research, which focused on 95 humpback “singers” from east Australia, found evidence that gradual song changes are due to embellishments introduced by individuals that are then learned by the rest of the group.

Songs introduced by revolutions may be simpler because the singers find it harder to learn completely new material, say the scientists.

Lead researcher Dr Jenny Allen, from the University of Queensland, said: “We examined two measures of song structure, complexity and entropy [a tendency to become more disordered] in the eastern Australian population over 13 years. Complexity increased as songs evolved over time, but decreased when revolutions occurred.” (© Daily Telegraph, London)