What happens to the bird parents after their young leave?

Do they come back next year together or find new mates?What happens to the bird parents after their young leave?
They will continue to care for the young outside the nest for some time. If they are a migratory species they will return to their wintering grounds and come back next spring. Yes, most males will return to the same territory year after year. The females too will usually return. In the case that one or the other does not show up..the birds will simply find other mates. Some species will form pair bonds year round.What happens to the bird parents after their young leave?
Depends on the species of birds. Some will come back and some will find new mates. Often they will return to the exact same place.
Many species are monogamous and return to do it all over again the next year.