© 2013 admin. All rights reserved. Night Monkeys April 10, 2013 Night monkeys are some of the strangest animals you might encounter in the Manu Biosphere Reserve. Also known as owl monkeys, they are the only truly nocturnal genus of monkeys. Here are some rare daylight pictures of them taken in Manu. The Black-headed Night Monkey – Aotus nigriceps They live amongst the canopy making them difficult to spot and hence difficult to study, less is known about them than the other monkey species in the Manu Biosphere Reserve. Because of their nocturnal life style they have no colour vision and see purely in black and white. Interestingly, the genus of night monkeys is one of the few primate genuses that is affected by malaria, other than humans.