Thanks for the research stlhead. I have alwasy heard that orca's attack whales, much like a pack of wolves attack much larger prey.

Of much interest to me was the one link about Monterey Bay, and the orcas that hang out there for the grey whale migration. I used to live and fish there.

It sounds like they are opportunistic predators, eat a lot of smaller prey, but catch the whales when they can like during migration. Much like the alaskan wolves wait for the caribou migration each year.
-rbf