25 April 2014
A sound like a duck heard in the Southern Ocean has confused scientists for 50 years. But the mystery has now been solved, according to research published in the Royal Society journal Biology Letters.
Click to hear the report
This is the noise that's puzzled scientists for more than 50 years. The mysterious sound can be heard in the winter in the seas around Antarctica and Australia.
It's nicknamed "the bio-duck" by those who think it sounds like a duck quacking.
Now researchers say acoustic recorders attached to two Antarctic minke whales have revealed that the bizarre noise is the animal's underwater chatter.
Scientists say solving this long-standing mystery will help them to learn more about these little-studied mammals and help them to establish where the whales can be found.
Click here to hear the vocabulary
given an informal name
making the sound of a duck
- acoustic recorders
machines which record sounds
unusual; very strange
(here) quick repeated noises
animals which drink milk from their mother's body when they are young