OCEANIC SING-ALONGS
In our recent posts we have talked much about the communication methods of whales and why a good hearing is essential underwater in order to survive the day.
Last, I talked about the baleen whales, which use low frequency sounds to communicate over great distances - not only to chit-chat with the individual a feeding ground away, but also to manage their annual migration between (sub-)arctic and tropical waters.
Also our beloved humpback whales belong to the baleen whales and are known to not only have one of the most complex language among cetaceans, but maybe even among mammals in general: apart from using moaning sounds for their day to day talks and navigation through the habitat they live in, they also have learnt to sing. Incredibly, these songs seem to follow certain patterns, and while some two sounds can follow each other, not every random sound can - much like a grammar. Humpback whale songs seems to be quite similar to our songs with melodies that follow verses and a chorus. Most of the sounds used are moans, shrieks and growls. A song usually lasts for about half an hour but might be repeated over and over again for hours non-stop - however, it is only sung by males.
But hold up, humpback whales are not only known to be loud - but they can just as much whisper to one another, especially the mother and calf! Whispering might serve several purposes, but most importantly it might be a way to protect the young whale from predation: Whilst an adult humpback whale doesn't have to fear its co-inhabitants of the wide ocean, young whales are an easy target for a pod of killer whales.
Whispering to one another using faint squeaks and grunts that can only be heard some tens of metres away at the most, therefore doesn't draw unwanted attention to the pair. Studies proved this sounds to be about 40 decibels lower than those of male humpback whales in the area, that compared to the whispers can be heard several hundred of kilometres away.
- Sarah
