I used to have a parrot with some health problems, and we'd feed him hard boiled eggs to help keep him healthy, and his weight up. He really loved them!
Oh ya, I have a pair of hawks on my street and they're always killing and eating birds, they especially like magpies.
Toe-to-toe on the ground or on a branch they truce, but as soon as the magpies take to flight the hawks outmaneuver them and take them out.
Sad, because I like corvids.. I wish they'd take out a few of the pigeons instead!
Yeah, most birds will eat just about anything. Obviously birds of prey eat other birds, but in fact a lot of birds that you think just eat seeds and fruits definitely eat, um..."proteins"! Sometimes it's just bugs, but even happy little parrots and toucans eat eggs and chicks of other birds as well as the meat of other animals!
My zebra finches ate hardboiled eggs & loved 'em. My book on finch welfare recommended it, so I found myself boiling eggs for finch breakfast before leaving for work & sieving them nice & small & tidy for the feathered kids.