Most of us are aware about the sounds produced by whales but we have no answers for why and how. Whales are social creatures which travel in groups called “pods”. Sunlight and odour do not travel well in water bodies but sound moves about four times faster in water when compared to land. That’s the reason most divers use hydrophones to attract whales or sharks to a defined area. Let’s see why whales sing and how many sounds a whale can make.
A point worth noting is that not all species of whales sing. Only Baleen whales like Blue, Fin, Humpback, Bowhead and Minke species of whales sing. These Baleen whales use larynx to produce sounds, whereas the toothed whales produce sounds using their larynx besides specialized air sacs near their blowhole. Whistles are produced from larynx and high frequency echolocation signals are produced from air sacs.
Whales make three types of sounds- clicks, whistles, and pulsed calls. Click sounds are used as an echo, whales identify the object when the sound waves rebounded and differentiate between a friendly creature and a predator. Whistles and pulsed calls are usually heard as squeaks, squawks and screams to human ears. To be clear, these are the sounds made by a whale while they are being killed or tortured by inhumane humans.
Do you know that Blue Whales are not just the largest but also the loudest animals in the world with vocalisations up to 180 decibels which can be heard from 160km away. Apart from clicks, whistles and pulsed calls, whales also communicate non-verbally by slapping their fins and tails on the surface of water.
One of the first theory argued that perhaps male whales sing to attract female for mating but this thesis was rejected by scientists when they used humpback whale’s song to breed female but interestingly a male whale approached the source of song sending scientists to a state of confusion. The sound of whales is not only harmonious and pleasant, if observed carefully the clicking of whale is used in the famous song “Kaathalae Kaathalae” in the famous movie “96”.
On account of human activities like boating, underwater construction, military sonar, seismic surveys of soil, etc the oceans are getting noisier which are hindering whales communication. Scientists have observed that Humpback whales are reducing singing because of noise originating 200km away. Over thousands of whales are being killed by humans for commercial purposes. If this pace continues, various species of whales would be extinct in several years.