I have heard a lot about the strong pair bonding between macaws.
Many people say that they pair for life.
The pair bonding between macaws is very strong indeed. They also appear to form bonds that are of lifetime strength. They are, however, no better than humans at these lifetime commitments. If you have a bird that has lost its mate, it will usually accept a replacement after the loneliness has taken hold. That's not to say that it will accept just any old bird as a replacement.