Despite its relatively large size and distinctive appearance, very little is known about the biology of the bear cuscus. However, it is believed to be the only diurnal member of its family, emerging at dawn to actively forage amongst the canopy for a variety of fresh leaves. Rather than jumping between trees, like the more acrobatic primates, the bear cuscus moves slowly, but efficiently, methodically placing each footstep (3). However, the bear cuscus spends the majority of its time resting, possibly because of the low nutrient quality of its diet (6). Related species are typically solitary; however, the bear cuscus is more often found in pairs (2) (3). Partners communicate and advertise their position to other cuscuses using vocalisations and olfactory communication, often depositing secretions from glands in the skin (2).
The bear cuscus is probably monogamous, producing a single young at a time. In common with other marsupials, the infant is very poorly developed when born, and largely develops in a pouch on the mother’s belly, where it suckles her milk. The quality of the milk changes as the infant develops, initially being high in carbohydrates, and later rich in fat. This unique adaptation allows the young to grow quickly, and females may reach maturity immediately after weaning (2).