Mr. B wrote:
It's all related to food. Especially where there are high concentrations of birds, due to the competition factor. I know we like to think of Bald Eagles as regal (being the symbol of our country, etc.) but they're really just like a big sea gull with talons and a bigger beak to take on bigger prey. And most of them are not fierce, although they look the part. In Alaska I have seen seagulls take food away from them. I've seen ospreys do the same here in Connecticut.
Yeah, essentially they're just scavengers with squeaky voices.