Nice Melons

Whale Watching is Fine, Just Don’t Stare at Their Melons

It is thought that at least 3000 beluga whales return to summer in the Churchill River estuary, reaching peak numbers by late July. They travel with the tides, entering and exiting the Churchill River twice a day, fishing on the tidal lines, basking in the warm waters (relatively speaking) and socializing.

Beluga whales are mid-sized whales. They measure up to 14’ and can weigh 1000kg, the males 1.5 times the size of females. They travel from their winter home in northern Hudson Bay and Hudson Strait, swimming slow but steady. This year, the first whales arrived on Friday, June 15th, scouts for an oncoming invasion.

They appear as periodic ice floes, only their smooth dorsal ridges breaking the surface of the water. It is not until you are peering down into the green saltwater tide or even swimming underwater that their appearance takes on an entirely new dimension. Swimming under and around your boat, these white whales take on an eery, otherworldly glow as they turn their head to meet your gaze.

And it is their head that truly sets beluga whales apart from other whales. Plopped on top of an otherwise dolphinesque profile is a blob of fat called their ‘melon’, an obese appendage completing an alien theme.

The melon is for more than looks, of course. It is a means of communication, transmitting and receiving, almost a big, fatty GPS unit sitting on your nose.

Beluga whales spend much of their time under the sea ice, in a dark and mysterious world. Without light, belugas must live and travel in a world of sound.

Sound travels easily and quickly underwater, over four times faster than on land. Belugas most commonly use a series of rapid clicks for navigation.

These series of clicks, called trains, are emitted by pushing air through their blow hole. The beluga basically ‘shoots’ a beam of sound (the train) through the water, changing the shape of its melon as it ‘aims’ the sound in a certain direction. By deflecting and focusing the sound, the melon plays a crucial role for the whale to communicate.

As these ‘trains’ hit an object, they bounce back to the whale. Since beluga whales have no external ears, this ‘echo’ is actually heard by the whale through their jaw bone. Vibrations travel through the jaw into the inner ear and are interpreted by the brain into a map of their underwater world.

This is called ‘echolocation’, similar to the method used by bats. Beluga whales are very adept at echolocation, even able to receive echoes reflected from the surface of the sea ice.

They are smart animals with big brains that are wired delicately and complicated, more complicated than ours, a hint of superior intelligence.

Echolocation is just one part of beluga whale culture. They vocalize with a wide variety of squawks, chirps, burps and whistles. Researchers have identified at least sixteen different vocalizations.

They also seem to use facial expression and body contact as further expression. They are the only whale without a fused vertebae in their neck, allowing belugas to turn and cock their head, only adding to the already wide range of underwater communication and adding to their truly alien appearance.

As more whales return and get comfortable in their summer home, more vocalizations can be heard. Try it for yourself, on a tour or from the beach, by an underwater microphone called a hydrophone or simply putting your head into the water!

- prepared by Kelsey Eliasson

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