Great White Sharks hunt seals near shore. The seals, in turn, hunt fish that often finds them going to sandy beaches where rivers meet the ocean. Humans like to swim and surf on these beaches. This forces contact between humans and the sharks.
Are there similar pressures to force Orca-human interactions?
Yes, orcas also hunt seals, sea lions, and other marine mammals that live on beaches. Orcas will even beach themselves in order to hunt these. And they've even been observed in freshwater rivers [1].
Are Oraca commonly found in water that won't cause hypothermia (eg death or unconsciousness) in less than an hour?
That would be warmer 50F==10C. Anecdotally, I have only seen or heard of people seeing Orca in the PNW and Arctic where swimming without a wet/dry suit is not only uncomfortable, but deadly.
Great White shark populations OTOH are concentrated in some of the most popular and temperate swimming areas in the world. Certainly, they are everywhere I have ever been swimming/diving.
Good question. But according to this map[1] there should be plenty of beaches where orcas and humans might encounter each other.
Given that orcas are able to learn how to drown white sharks, and catch birds by baiting with fish, couldn’t it just be that they have learned not to hunt humans, as they’ve experienced retaliation in the past? I’m pretty sure pre-historic humans would somehow retaliate if an orca grabbed a child from the beach and, because of that, it would make sense if orcas have simply learned not to do this.
Orcas do have large populations near Antartica, Norway, and Alaska, but they also have large populations along the American West Coast, Mexico, and Australia. The Global Biodiversity Information Facility has some good maps of observation recordings around the world for these two species.
Are there similar pressures to force Orca-human interactions?