A group of scientists have now claimed that Whales, which already endangered, could be saved by tracking their sounds. They found that whales produced different sounds during the day time and night.
The whales shifted from singing at night to caroling during the daytime when they begin migrating, the scientists said in the study that was published in the journal Current Biology.
They tracked whale movements and songs over several years. They found that the biggest mammals switched from singing at night to caroling during the daytime when they begin migrating. They noted that tracking the two sounds could help in protecting these endangered animals as they move towards busy shipping lanes.
William Oestreich, a PhD candidate in biology at Stanford University and co-author of the study said that now it was clear to see what these animals were doing in the habitat. From the sounds, the movement of the whales in southern California were detected, the researcher added.
Blue whales undertake one of the longest migrations each year. They spend the summer in the Northeast Pacific and then they travel thousands of miles to their breeding grounds off the coast of Central America.
Oestreich and his colleagues planted an underwater microphone (hydrophone) outside Monterey Bay and recorded the sounds over five years. They also watched the behaviour of 15 singing whales over periods of days to weeks. The researchers stuck a tag on whales back that included GPS trackers, accelerometers and pressure sensors that could detect fine scale vibrations that can reveal when a whale is singing.
Male blue whales are only known to sing. However, both the male and the female move southward at about the same time each year. Both the male and female have been spotted pairing up and feeding together just before the migration. This indicated that the sound produced by the males represented the whole population, Oestreich said.
The scientists found that the songs picked up by the hydrophone were mostly at night. The intensity of the songs reached a peak each year between October and November. However, as winter approached and the songs dwindled, the whales switched to singing during the daytime.
During summer days, the whales are known to dive to great depths in search of krill. Once night comes, the whales hung out near the surface and sing for hours on end, the researchers noted.
Oestreich said that the whales movement could be traced using the sounds. This could help in avoiding collisions between the ships and the whales.