Lincoln Park Zoo Welcomes a New Bolivian Gray Titi Monkey

Chicago (September 11, 2026) –Tails are twining and love is in the air at Lincoln Park Zoo! Female Bolivian gray titi monkey Tacama has joined longtime male resident titi monkey Ocho at Helen Brach Primate House. The two have already hit it off, and their care team has observed the hallmark sign of compatibility and bonding for this species: tail twining. This is when two monkeys sit beside each other and wrap their remarkably long tails together to reinforce social bonds—similar to how humans hold hands.

Tacama is 14 years old and comes to Lincoln Park Zoo from another accredited zoo through the Association of Zoos and Aquariums. She has a breeding recommendation with 14-year-old Ocho through the Bolivian Gray Titi Monkey Species Survival Plan®. This is a collaborative population management effort among institutions within the Association of Zoos and Aquariums. The hope is that the two will have babies in the future.

“We’re excited to see such remarkable compatibilities between Ocho and Tacama,” said Dani Fogarty, Curator at Lincoln Park Zoo. “The two hit it off almost immediately upon introduction and they continue to choose to spend time together, often with their tails intertwined, sitting on one of the many branches in their habitat.”

Bolivian gray titi monkeys inhabit humid, tropical forests and swamps in the southern portion of the Amazon River basin. As an arboreal species, they very rarely come down to the forest floor. The species is known to form small, territorial family groups made up of one monogamous adult pair and several offspring. Females may give birth to a single offspring every year after a 160-day gestation, typically during November and March. Males help care for young by carrying them when females are not nursing.

The average Bolivian gray titi monkey is around 13 inches long when measuring their head and body, but their tails are an additional 15 to 18 inches long. The tail is not prehensile, meaning it can’t grasp things like the tails on certain other monkey species. In addition to tail twining, titi monkey pairs will often duet as a way to mark their territory, which can be heard as far as a kilometer away. The species makes more complex and varied sounds than many other neotropical monkey species.