SteveMeister
Hang out with Steve.
I'm beginning to get the impression that Owen has been around these raptors for years thus they have a sense of familiarity. Like any other animal, whatever they see as a guardian or protector, or nurturer even could be a factor here.
That's what I think as well. In fact I wonder if they're posturing aggressively not specifically towards Owen, but towards other people who are off-camera, and that's why he says "Eyes on me!"