Do you let your birds out of their cage?

If they are like parrots and cockatoos that can behave themselves, they won't need cages. I've seen the tricks these certain birds can do and I've read somewhere that they have the intelligence of a five-year old, which is not really hard to believe. However, birds in captivity are in a way, losing their identity. They ought to be in the wild populating the world with more of them. I would hate for these birds to be on the brink of extinction