Monkey Tales: Night Monkeys

June 20, 2014

Is there such a thing as a nocturnal monkey? Yes, and only in the New World tropics and they go by two different names, both of which are very fitting: the Owl Monkey or Night Monkey.

The Peruvian Amazon boasts a tremendous diversity in primates and in areas of the Upper Amazon Basin from Iquitos to the Pacaya-Samiria Reserve there are 13 species. There is greater diversity in this region, where we conduct our 10-day Amazon River cruises, than any other place in the world. The owl monkey is a pretty little monkey with extremely large eyes -- the better to see you with (at night) my pretty! In the beam of a spotlight, the eyes reflect back very brightly and it allows for easy spotting these otherwise very elusive and cryptic monkeys. Only on occasion may a visitor to the area be lucky enough to see an owl monkey or owl monkeys peering from a tree cavity during daylight hours; however, Amazon tour guests frequently see these guys during the day on our rainforest hikes around Ranger Station #2. Usually daytime is a time for sleep and slumber and at dusk is when the owl monkeys alarm goes off. Owl monkeys live in small groups, usually within the same tree cavity and often in a cavity that has a riverfront view. As night descends on the forest, owl monkeys begin to stir and they often call to one another with a three-hoot call, much more owl sounding than what one might think a monkey should sound. 

Owl monkeys feed on a variety of fruits as well as insects and small vertebrates. The long tail is used mainly for balance and unlike some other New World primates owl monkeys do not have a prehensile tail. In addition, due to their nocturnal behavior, owl monkeys do not have other primate competitors for in foraging but certainly other mammals, such as opossums, kinkajous and arboreal bamboo rats may compete for the same ripe fruits. Baby owl monkeys are extremely adorable creatures with huge liquid brown eyes. Because of large eye size, owl monkeys always appear to be staring. The blink of the eye is extremely quick and almost is undetectable to the human eye, thus the appearance of staring. In regards to vision, quite a bit of research has been done with owl monkeys due to their nocturnal behavior. It appears that owl monkeys are basically color blind, but their eyes respond much better to movement, such as fleeting insects and of course superior vision in very low light, unlike any other primate.

Unfortunately, owl monkeys as well as other primate species in the Amazon, are under a tremendous amount of hunting pressure from the ever expanding population of riberenos people in cities, towns and villages. It is quite apparent when visitors to the Amazon see baby animals in villages, sometimes lots of animals from parrots to caiman and monkeys to turtles. Visitors are usually asked a nominal fee to have their picture taken with an endearing animal. Usually these animals are said to be orphaned and that typically is the case, but only because the parent or parents were killed for the food pot and then the terrified baby animal or bird is brought back to the village for commercial gain. It is always best to avoid contact with animals in villages and certainly do not promote the practice by paying to have your photo taken with a cute baby monkey or any other wildlife species.  


Naturalist Greg Greer is a favorite among IE travelers, and has gained a reputation for his friendliness and good humor, along with his incomparable knowledge of natural history. Greg's photos and articles have been widely published in books and magazines, including Georgia Outdoor News, Bird Watcher’s Digest, Alabama Outdoor News, Riversedge and Southern Wildlife.