Would you believe us if we said that humpback whales have playlists of songs that they “play” during breeding season – and change them at will? No? Well, a new study published claims just that.
Singing whales play DJ
Male humpbacks call out to females by “singing” – that is a known fact. But something interesting has recently come to light through an 11-year study conducted by the University of Queensland researchers and published in Current Biology. The researchers believe that this song changes – that is, the male humpbacks change their songs slightly so they can be different from the friendly neighborhood humpback. That is not all apparently.
Sometimes, humpbacks pick up a tune from another whale and adopt it as their own. And these songs move through whale populations – a sort of horizontal transmission (as opposed to passed down through generations).
This is like a change in whale culture among many humpback populations! Researchers claim this is the first such documentation. What is astounding is that this transmission of the whale “playlist” occurs over a period of about two years and over the entire western and central South Pacific – a huge area!
Whale sounds and songs are called echolocation. They consist of sequences of groans, roars, sighs, and squeals that can last up to 10 minutes or longer. Different types of whales use these sounds for different reasons: hunting, navigating and communicating. Whales called baleen whales (like blue whales – the biggest mammals on earth, and humpbacks) produce a series of these sounds called “songs” for communicating.
And how do they produce these sounds? The toothed whales – like dolphins and killer whales make these sounds by moving air between the air-spaces (also called sinuses) in their heads. These sound waves travel through water and are reflected back from objects. The reflected sound waves are received by an oil-filled channel in the lower jaw of the whales and then transmitted to the middle ear.
When whales swim and emit these sounds, they are collecting information from the sea or ocean floor and prey locations as well as other obstacles in their swim path.
Man-made noise. Since the 1960s shipping traffic and naval submarine-hunting exercises (where they use sound waves to look for submarines in the area), oil ships looking for oil in the ocean floor have increased the noise in the ocean. This noise is drowning the whale songs out. Since crucial communication between whales happens with sound, this issue threatens them in a very serious way.
But all is not lost. Science is helping this situation by transmitting whale locations to ships in the area so they can slow down or alter their route to avoid the whales.
[The study on which this article is based, can be found in Current Biology here]