They are known to form pair bonds, as well documented in the majority of gibbon species.
In some species, males and females form lifelong pair bonds.
He is alive; one can tell from observing you that the pair bond remains intact.
During these four or five years they form pair bonds with a mate that they will keep for life.
They are thought to form pair bonds for the duration of a breeding season.
Migratory species however are thought to form new pair bonds each breeding season.
If they are used for breeding, a pair bond appears to have formed.
When they leave for winter quarters by early August or so, what little pair bond existed during the summer is broken up.
These pair bonds take several years to develop in some species, particularly with the albatrosses.
Successful breeding and pair bonds, however, doesn't usually occur until 4 to 5 years of age.