Researchers have recorded, reportedly for the first time from the waters off Kerala, the song of blue whales.
A hydrophone deployed off Vizhinjam to capture the sounds of migrating humpback whales had instead recorded the call of the endangered blue whale.
While humpbacks are known for their high-frequency vocalisations, blue whale songs are a series of short, low-frequency moans.
Whale sounds (moans, cries, chirps and cries) are essentially communication tools, for activities such as socialising and mating.
Call patterns can vary from population to population.
So far, the presence of blue whales in the waters off Kerala have been reported through a few carcasses that beached. But the recording of their calls confirms their presence along this stretch of the western coast.
About blue Whales:
The blue whale was once abundant in nearly all the Earth's oceans until the end of the 19th century.
It was hunted almost to the point of extinction by whalers until the International Whaling Commission banned all blue whale hunting in 1966.
The International Union for Conservation of Nature has listed blue whales as endangered as of 2018.
It continues to face numerous threats, both man-made (ship strikes, pollution, ocean noise and climate change), and natural (killer whale predation).
The blue whale is the largest known animal to have ever existed.
Pygmy blue whales
Though the larger blue whale populations are found around Antarctica where krill, their favourite food, is available, the occurrence of pygmy blue whales is reported in the Indian Ocean.
