They kill and eat fish, seals and even whales…why not people?
Rudyard Kipling described it, in the Just So Stories: How the whale got his throat
[sub]Sorry, I couldn’t resist.[/sub]
Mostly lack of opportunity. There are a few incidents on record.
Because they would rather jump through hoops and balance balls on their nose?
In aggregate they do, but individuals and groups are food specialists. Those that eat fish don’t prey on marine mammals, for example.
Specializing in humans would not have been a profitable adaption.
Obligatory Wikipedia:Orca link.
Please don’t call them “killer whales.”
Your link seems to feel this is okay:
The same reason they don’t eat floating logs. Most animals are adapted by evolution to eat certain forms of prey and ignore everything else as a waste of effort. Humans have never been a prominent enough form of prey in the water for any marine carnivore to evolve to putting us on the menu. I’ve read that most attacks in the ocean against humans happen because the person does something that confuses a shark, barracuda, or orca into thinking the person is something like a seal or tuna.
Apparently there are two types of Orca, those that eat fish, and those that eat mammals. I saw on Discovery they even make two types of noise. The seals aren’t afraid of the orca that make a certain noise, but if they play the call of mammal eating orcas the seal take cover.
It’s interesting in areas where seals have declined orca now eat sea otters, really reducing their population, which seems to indicate that given an adequate supply of their normal food, seals, they won’t touch sea otters.
That kind of relates to the original questions, why bother with humans when their regular food, seals are abundant.
And penguins. They eat penguins.
I just had a bar discussion about this the other night. We came to the conclusion that they should be called “voluntary homicide whales.”
In Seward, AK, I have heard rumors, hearsay or innuendo, that missing kayakers may have been attacked by killer whales. Apparently there have been reports about kayakers being approached by Orcas and the kayaks being bumped. The stories are all FOAF.
Besides, the places where these animals live (pacific northwest and alaska) are just too cold for humans to be swimming in.
Native stories from the frozen north have people being eaten by whales, but then again the stories also have people being eaten by - eagles, ravens, dog headed people, people, bears, ice bears, walruses, etc…
Apparently Orcas will supplement their diet by eating land mammals like deer, moose and even polar bears. I’d guess that you’re normal size healthy human being has relatively little fat content and as such wouldn’t make great Orca food.
While lots of people still call them killer whales, my point is that they shouldn’t be called that, for two reasons:
They aren’t whales, and
They don’t kill humans.
On a site devoted to the Straight Dope, I’d think that sort of myth perpetuating name would be anathema. 
Well, they are cetaceans, and thus closely related to whales. Since we put up with such things as polar bears far from any pole, grizzly bears that are seldom grizzled and black bears that are rarely black, this seems like something that can be tolerated.
As for the “killer” part, it’s news to me that this necessarily implies “killer of humans” though I can easily believe some take it that way. Note that Orcinus orca isn’t necessarily an improvement. Wiki says:
Other posters have noted that Orcas/Killer Whales do kill on occasion, usually people who interact with them in captivity.
hotcoldhot mentioned resident and offshore pods of Orcas, so just to add to that:
From a PDF here, on a NOAA site, but written by The Marine Mammal Center’s education department.
On why the Orcas are called “Killer Whales” and whether they kill people in the wild:
Same source as above - and the source is dated as of 2002, so I think it’s likely still true ;).
On why the Orcas are called “Killer Whales” and whether they kill people in the wild:
They kill their preys, in opposition to the krill-eating whales.
I do not understand this. My impression is that predators are not overly picky. Certainly they have a preferred prey food wherever they live but they are not likely to pass up a free lunch just because they have never seen it before. I doubt a hungry lion would give me a pass just because it has never seen a human before.
Well, it depends.
Predators often specialize in one particular type of prey. This can be species wide, or individual.
Sure, a hungry lion could kill you and eat you. But it might decide to leave you alone and concentrate on prey species it specializes in. Predators don’t just attack everything in sight, they have to carefully assess the risk of attacking a potentially dangerous animal. Most lions seem to believe that humans are dangerous and should be left alone. But some lions decide/discover that humans are tasty and easy to kill. But the typical fate of a habitual maneating lion is that it’s hunted down and killed, proving that the human-avoiding lions were right all along. Lions live in an area where there are lots of potential prey species that have the potential to kill a lion if the lion isn’t careful. A bonebreaking kick from a zebra could mean death if the injury doesn’t heal before the lion starves to death.
The other thing to consider is that predators often aren’t hungry most of the time. Think about it this way, a predator on the ragged edge of starvation is in serious trouble, because it’s going to be weak and sick. Even if it came across a prey species it might be too slow to catch it or too weak to kill it. More typically a predator has no trouble finding enough food…most of the time. But then some slow time occurs…drought, winter, population crash of prey species, or whatever, and suddenly the predator that had no trouble finding food is starving. If a predator’s life depends on catching the next prey item it sees, then most times that predator is going to be dead, therefore the average predator can’t be starving because most starving predators die.
So now we have to worry about the Land Orca :eek: ?