Researchers have analysed recordings from three locations in the western Indian Ocean from where they discovered the unique whale song.
The discovery of whale song indicates the presence of significant population of whales in that part of the sea as whales uses songs to socialise.
Whales use songs to communicate and socialise. Their songs can be characterised as clicks, whistles and pulsed calls or a composition of moans, snores, chirps and cries.
Not all whales sing. Only some, such as the baleen whale, have been found to sing songs.
Whales use clicks to navigate and identify their surroundings as the sound bounces off objects, helping whales determine their shapes. Whales use whistles and pulses, on the other hand, during social activities.
Whale songs are typically below 4 kHz in frequency. Some blue and fin whale songs are so low in their frequency that parts may be inaudible to human ears.
Whale songs can last between 6-35 minutes, and some individual whales have been found to sing for 22 hours.
The new discovery
Researchers have recorded the unique song off the coast of Oman in the northern Arabian Sea, off the western Chagos Archipalego, and off Madagascar in the south-western Indian Ocean.
Since it is the only blue whale song identified by them in the western Arabian Sea, researchers have called it the “Northwest Indian Ocean”.
Significance of discovery
Given that this song-type has not been reported before, the presence of it across a large geographic region indicates the likely existence of a previously undefined population of blue whales in the Western Indian Ocean.
Researchers believe the source is either the blue whale or Bryde’s whale since both species have been documented off Oman previously.