Mason Professor Witnesses Rare Birth of Titi Monkey in the Wild

By Michele McDonald

A male titi monkey with its offspring. Photo ©Anneke DeLuycker

A male titi monkey with its offspring. Photo ©Anneke DeLuycker

High in the South American jungle, a titi monkey gave birth in the wild and a George Mason University researcher saw everything from when labor pains began to the newborn’s arrival.

“I only had my hand-held video camera with me, and I was so excited that my hands were shaking,” says Anneke DeLuycker, assistant professor at the Smithsonian-Mason School of Conservation. “I knew that we were witnessing something very special and never-before filmed.”

For nearly a year DeLuycker roamed her field site near the Río Mayo in the foothills of the Andes Mountains in northern Peru to study a specific group of Andean titi monkey (Callicebus oenanthe). Her findings were published this summer.

One morning, DeLuycker noticed the female acting a little differently from the rest of the group. “I began to notice that the female had stopped foraging and was resting quite a bit, and she was laying or crouching down on the branches,” DeLuycker says. “Soon I noticed she was experiencing contractions—belabored breathing—and I realized…she is going to give birth! I quickly radioed my field assistant to bring another camera and help in filming.”

Professor Anneke DeLuycker. Photo ©Anneke DeLuycker

Professor Anneke DeLuycker. Photo ©Anneke DeLuycker

It’s rare and remarkable to witness a primate giving birth in the wild, especially during daytime, DeLuycker says. Plus, titi monkeys make their homes in the trees so they’re usually very high up in the canopy or hidden by leaves, making it difficult for even the most watchful observer to see them.

“It was quite exceptional and incredible to witness,” she says, adding it was well worth the extra mosquito bites. “I feel very fortunate!”

Titi monkeys with their pensive faces and long tails are small-bodied South American primates. They form small families or pair-bonded groups comprised of a mother, a father and their offspring. The father is the main caretaker of the offspring. This is unusual, DeLuycker says, adding that males in other animal species also provide primary parental care but rarely so pair-bonded groups.

“In the video, you can see the male (on the left of the screen) reach out to touch and inspect the newborn at various moments and this first occurred about three minutes after the female gave birth,” DeLuycker points out. “The events of this birth, in particular the male’s role in the birthing process, gives us new insight into the male titi monkey caretaking behavior.”

She notes while there may be individual variation in behavior, the video shows that this particular male makes an immediate, strong bond with the infant. For the next five months the infant’s father is the main caregiver.

“The male is the only one that carries the infant for the majority of the time and he also has a significant role in protection, rescue, play, and grooming of the infant,” she says. “Based on observations made during my long-term study of the behavioral ecology of this species, I hypothesize that the immediate, extensive infant care given by the male serves to establish his bond with the infant and reinforce his infant care duties, which frees the female from such tasks and allows her more time to forage. This ultimately increases the reproductive output potential for the female.”

The Andean titi monkey is critically endangered and is on the International Union for Conservation of Nature Red List of threatened species. It lives only in a small region of northern Peru.

“I hope to promote more awareness and knowledge about this species by telling people about its behavior and where it lives and why it is important to save, and I want as many people as possible to see the video,” DeLuycker says.