Because of the many sightings of sun bears in pairs, it is thought that at least some of these bears may form monogamous relationships.

They can breed at any time of the year and the cubs are born in a nest on the ground. The naked, blind cub is cared for and protected by its mother (and perhaps the father as well), and sun bear mothers often carry their cubs in their arms while walking upright – bears have plantigrade feet as do humans. [...]