Like the nocturnal bird for which they are named, owl monkeys are the only known species of nocturnal monkeys.
These animals are also compared to owls due to their very small external ears, which give them a round bird-headed appearance and very large owl-like eyes.
A major difference between owls and owl monkeys is that owls are predatory birds and owl monkeys eat mainly fruits and plants.
They will occasionally eat small insects when their normal food is scarce.
They are more active during nights when the moon is brightest relying on their keen sense of depth perception rather than using color distinction as the daytime species of monkeys would.
Owl monkeys do not form a large group as many other New World species of monkeys do.
Their range in Central and South America is from sea level to mountainous areas.
The higher they live above sea level, the greater the thickness of their fur.
They are found at all levels of canopy in the rainforests and are rarely if ever seen on the ground.
They prefer to sleep during the day in tree trunk cavities or in thick brush and have their activities during the late evening and at night.
Small family groups will consist of a mated pair and one singleton born per year that will leave the family unit after a couple of years.
This creates a family unit of up to 5 if the young are slow to leave the family.
They were once thought to be totally monogamous, but the original pair can be split up during the life of the family.
This is partially due to the fact that males and females mature at different ages, so naturally they will reach their sexual peak and decline at different times.
Mature adults from other groups will show aggression if they wish to become the new member of the family and if the existing mate is unable to fight them off, they will surrender.
The males have the role of carrying the young, except during the time of nursing.
It is believed that the males sense they are stronger than the females that are weakened by pregnancy, birth, and nursing.
The males would be more capable of getting the young to a safe area in an emergency or if the group were attacked.
If the male is attacked or killed, however, the female will usually not resume the primary care for the infant.
Sometimes a sibling will be old enough and strong enough to take over, or else the infant will be lost.
This is normal in nature with other species too.
These male primates are also in charge of discouraging the young from nursing and being carried.
This often causes stress and conflict within the family.
Owl monkeys are very interesting for their oddities and their differences from other monkey species.