Whales found to be changing their tune

Sydney University scientists have recorded a shift in the singing of humpback whales in the past five years said to be as dramatic as the difference between punk and pop.

Sydney University scientists have recorded a shift in the singing of humpback whales in the past five years said to be as dramatic as the difference between punk and pop.

The team from the Marine Mammal Research Centre, led by Michael Noad, reveal
their findings in the scientific journal Nature.

Between
1995 and 1998 the scientists, partly funded by the Australian Stock Exchange,
analysed 1,057 hours of whale songs. A typical humpback song runs for between
seven and 15 minutes, usually containing about seven "themes" – akin to verses
in a human song.

The singing is broadcast by the humpback
males at an enormous volume – about 170 decibels or the equivalent of the noise
emitted by a cruising container ship.

In 1995 and 1996, Mr
Noad heard two humpback whales out of 82 on the east coast singing a new song.
The song was similar to the tunes sung by whales on the west coast of Australia,
reports The Age.

"Most of the 112 singers produced either the old or the new song,
but three used an intermediate song containing themes from both types," says the
Nature paper. "By the end of the 1997 southward migration, almost all whales had
switched songs and in 1998 only the new song was heard."

Mr
Noad says the new song is popular "because of the novelty", adding: "The whole
theory of novelty is that it stops females from getting bored. If you are a
female sooner or later you are going to get tired of a song sung by the males.
But if you are a female and suddenly there’s a male that’s singing something
different, a little bit innovative, then he will stand out from the
crowd."

A radical song replacement such as that discovered
by Mr Noad has never been recorded in any other animal.

The
old song and the new song, apart from being distinctively humpback tunes, have
no similarity in structure. "It’s like the introduction of a new fashion. It’s a
bit like ’80s rock suddenly being replaced by punk," Mr Noad said.

Author: not credited

News Service: AnaNova

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