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PRB
November 29th, 2009, 16:38
Watched a show on one of those science/discovery channel stations. It was amazing. It seems Killer Whales (Orcas) attack and eat Great White sharks. Who knew? But second most interesting is how they kill them. Have you ever heard that if you turn a shark over on it's back it will go to sleep? Researchers use this knowledge to tag sharks routinely. They get them along side the boat, flip them over, wait until they're “sleeping”, then tag 'em. It seems that orcas have figured this out as well. There is film of a Killer Whale off San Francisco holding a Great White shark upside down. The next film opportunity of the ill-fated Great White featured only his liver, which has being fed upon by the orcas. The actual ripping to shreds of the shark by the orcas was not actually captured on film.

When I first started watching this show on the TV, I thought the researchers, in typical PC fashion, were going to attribute the orca's attack of the shark to protecting the tourists on the boat, from which some of the footage was shot. But it seems Killer Whales often do kill sharks, in this same way, by first putting them to sleep by turning them upside down.

But what's most interesting about this what the whale researchers call “cultures”. Not all Killer Whales kill sharks, and not in this way. Some Killer Whales, off South Africa, swim up on the beach to catch seals. Other Killer Whales, in more northern latitudes, learn to make waves,which drive the seals off the ice chunks they're resting on, into the water, were they are promptly swallowed up. Other Killer Whales kill sharks by ramming them, turning them upside down until they fall asleep, them eating them. The whales that know how to wash seals overboard from their ice chunks are not the same ones who drive up on the beach to catch seals in South Africa. We know this by the knowledge that has been gained by tagging and tracking individual whales.

Interesting.

Wing_Z
November 29th, 2009, 19:55
And they do not catch humans.
We had a scare last weekend, some snorkelers quite close to shore were in the way of an Orca chasing down a stingray.
The ray, not them, ended up as dinner.

There's a brilliant Youtube clip of a penguin getting washed off its icecube by the Orcas, and then jumping into a spectator boat, to safety!

Emil Frand
November 30th, 2009, 04:47
I saw that as well, very interesting. There are basically two types of Orca groups, transient and resident. Transient Orca eat anything they come across in their travels, once in Alaska we saw a moose and calf swimming between islands that got attacked by transients, the cow escaped but the calf was eaten. Another whale watching trip a group attacked a pod of humpbacks with the intent of having a humpback calf for a snack, this attack lasted about 40 minutes with the attack unsuccesful. Saw another attack on a sealion which didnt end well for the sealion.
There is no recorded incident of an Orca attacking a human in the wild though there was an incident at Seaworld years ago where an Orca attacked the trainers during a performance. My sympathies lie with the Orca in that instance.

FAC257
November 30th, 2009, 14:44
I was amazed during this last year when I read that scientist have been studying a permenant population of Orcas that live in the Gulf of Mexico.
They stay mostly in the northen part of the Gulf between Texas and Florida feeding on dolphins & tuna.

That just seemed so odd as I thought Orcas were strictly cold water beasties.

FAC

demorier
November 30th, 2009, 14:55
I think we need some more Orcas around this way, then we could get rid of the shark nets....there's no shortage of sharks, whites and everything else. I've seen these doco's on TV before, I think they call it Catatonic or something like that (rolling over on there backs so they go to sleep).

MaddogK
December 1st, 2009, 07:31
Orcas have always been my favorite mammal. Did the show mention they mate for life ? Or that they (like man) will act out of revenge ?

Eoraptor1
December 1st, 2009, 10:19
You impress me, PRB.

JAMES