Is it normal for a bass to eat.....?

Is it normal for a bass to eat birds? Its sound kinda weird but today when i was fishing in my pond i caught a 3 pound bass and when i was getting my popper out of its mouth i say 2 bird legs and the birds claws sticking out of its throat. My pond doesnt have very many/no bluegill in it so i think that's why it had to eat a bird, i have also noticed that since there is no bluegill for the bass to eat they are eating all the little bass. Should me and my dad get more bluegill in our pond?