It has been mentioned before by real experts, birds reflect their dinosaur ancestors. I enjoy watching the behaviors of my ducks, geese and chickens. Behaviorally, they occupy three different biological niches and are thus not direct competitors. But each have a personal space just as we humans have. The chickens have the least individual behavior and the geese have the most. I believe the geese recognize individual humans and dogs and cats. They can be very personable except during breeding and nesting. The other two not so much.

The chickens are the scariest as they are predatory machines and exhibit no personality other than pecking order. They react to a food item in a purely predatory manner, no cooperation. If they were 20 ft tall and weight a ton there’d be a horror.

The cassowary is behaviorally in that line.