Earlier quoted context omitted.
My amateur theory is that talking makes you less likely to be a predator. You basically say “here I am”, Predators tend to be quiet and sneak up on their prey. I think the tone does indeed help somewhat in my experience.
I have an amateur theory that strange wildlife, unlike strange people, are made much more comfortable by avoiding eye contact. Parent comment would explain this observation: predators gaze upon their prey. (flipping the arrows around, I've seen the advice to dance tango, not so much with "snappiness" as is popularly supposed, but in a predatory manner: slow stalking, interspersed with rapid pounces)
I’ve also noticed with many birds that they prefer indirect attention. This includes not just eye contact, but pointing a camera (or really anything) in their direction. Which unfortunately means I have very little photographic evidence of the many times I’ve had birds just hanging around being pleasant companions for a while.