The female gibbon in question at Mori Kirara in the Kujukushima Zoo & Botanical Garden resides alone in her enclosure, and doesn’t live in conditions that enable direct contact with males. The zoo will attempt to solve the mystery using DNA testing.
Momo, a 10-year-old lar gibbon, was found by zoo staff on the morning of Feb. 10 to have given birth to a baby ape. The unexpected development confused staff; in the around seven-month period she appears to have been pregnant, Momo hadn’t had any sort of breeding sessions or any other activities where she shared her space with any male apes, nor had her stomach grown large enough to visibly suggest she was pregnant. Because of that, the director of the zoo, Chikako Iwaoka, initially thought she’d misheard the report when the employee who discovered the baby told her what happened. Baby primates don’t grow on trees, though, nor do they get delivered by storks like in the opening scene of Dumbo, so the zoo began looking into how this could have happened, and they’ve got a theory.
For about five or six years, Momo has lived in her enclosure alone, and she lives next to cages where other lar gibbons, siamang gibbons and other animals are kept. Between their enclosures are wire-mesh fences and boards.
Her enclosure is part of a structure with three others connected to it. Two of the enclosures contain one male lar gibbon each, and one of them contains three. There are metal grates in place between the enclosures to keep the animals out of physical contact with one another, but an inspection following the birth revealed a small hole, roughly three centimeters (1.2 inches) in length had been torn in one of the grates, and the zookeepers suspect that it was through this opening that Momo “encountered” the baby’s father.
The zoo says it intends to ascertain the father’s identity through DNA analysis of the baby’s hair or blood after it has been weaned, and put up metal boards at the borders of the enclosures to make sure that love doesn’t once again unexpectedly find a way. As a zoo for which planned reproduction is one of its principles, the emergence of an unforeseen pregnancy and birth is unacceptable.