Carousel Feeding Orcas

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Vengsøy island, County of Troms, Northern Norway, 23/11-2016

Since we arrived Troms in Northern Norway about four weeks ago, I have spent plenty time underwater to film one of the marine species I admire so much. As promised in my last post, here is a blog consisting solely underwater images of these gracious creatures :-)

The orca is a toothed whale, and the biggest member of the dolphin family. These highly social marine mammals normally live together in big, stable family groups, and are found in all oceans, from Arctic and Antarctic regions to tropical seas.

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Sometimes, the orcas are called "the wolves of the sea", as they are compared to hunt in groups like wolf packs. But the most common name for this apex predator is "killer whale".

According to some authors, this name is an old mistranslation of the 18th century Spanish name "asesina de ballenas" which means "whale killer". It is said that the Basque whalers would have given them such name after observing pods of orcas hunting baleen whales.

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The orcas are featured in many mythologies and cultures, and have got a wide range of reputation from being the souls of humans to the most merciless killers. In earlier days nobody dared to enter the water if an orca was in sight...

Today we know more about these majestic creatures. They are no merciless killers, but intelligent mammals specialized in different prey.

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In the wild, there have not been any injuries or fatal attacks involving humans and orcas. The several incidents we all have heard about are only involving captured orcas, trapped in small tanks where they get abused and forced to make tricks for human entertainment...

I have spent a lot of time in the water with the orcas here in Norway, and have never felt any agressive behaviour from their side. Instead they are very gentle and often quite curious.

What I think is very important though, is (like always) to behave in a calm and respectful manner when visiting these powerful beings.

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The orcas hunt a great variety of prey including both fish, cephalopods, seals, sealions, whales, sea birds and sea turtles. They are however specialists, which means that the orca's particular type of prey differs a lot between the different populations. In the waters off Norway, the Norwegian orcas specialize in herring which is their main food source.

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The orcas here have adjusted their movement to the herring's new migration routes, which is why there are so many whales currently gathering in the fjords of Troms during the darkest months every year.

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The Norwegian orcas use a specific method to efficiently hunt and feed on the herring. To trap the school of fish the whales have developed a special technique  called "carousel feeding".

Below is a brief description and some pictures to show how these elegant marine mammals do to get their lunch! ;-)

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Their "carousel feeding" is a cooperative teamwork, where the orcas approach the school of fish in a similar way to sheepdogs herding their flock of sheep :-)

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The whales isolate a patch of herring in the deep with the aim to bring it closer to the surface. To do so, the pod of orcas release bubbles and show their white underside of their bodies to round their prey into a tight defensive bait ball.

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When this is achieved, the orcas slap the edge of the ball with their tails (tail-slapping), which numbs or kills up to 10-15 herring with each successful slap. After this, the whales gently starts to eat the herring one by one.

Bon appetit!! :-)