A Titi monkey who is the oldest mother of her species to give birth in a North American zoo welcomed her ninth offspring last weekend at Lincoln Park Zoo, officials said.

The new baby monkey, weighing only a few ounces, was born Aug. 18 to seasoned Bolivian gray Titi monkey parents Delasol, 21, and father Ocala, 15, according to a news release from Lincoln Park Zoo.

Officials at the zoo have not named the new monkey because they have not been able to determine its gender. They have only seen the newborn monkey's face.

"The baby is spending most of its time nestled in the thick fur on mom's back, but we do get a glimpse of its little face peeking up now and then," said Curator of Primates Maureen Leahy in the release. "Dad and the siblings are playfully curious with the new arrival and the whole group is responding appropriately to the addition."

Officials said Titi families are known for being tight-knit and the fathers and siblings pitch in with newborn duties. Usually Titi families sit on the same branch and intertwine their tails, officials said.

Delasol and Ocala are part of a Titi Monkey Species Survival Plan and are one of the most successful couples on record, officials said.

Delasol gave birth to her eighth offspring, a male named Ocho, last October.

The whole Titi monkey clan can be seen at the Helen Brach Primate House.

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