Zookeepers finally crack the mysterious case of an isolated gibbon's pregnancy

Editor's note: This article was originally published on February 22, 2023. It has since been updated.

It's a tale as old as time: A girl meets a boy, the girl gets pregnant and the zookeepers search for the father. That's exactly what happened at Kujukushima Zoo & Botanical Garden when Momo the Gibbon became pregnant two years ago. After much investigation, zookeepers have finally identified the father of Momo's son to be Itoh, a 34-year-old agile gibbon. Move over, Maury Povich, and make way for the gibbons!

Momo the Gibbon had the zoo officials scratching their heads when she became pregnant two years ago. How could she have become pregnant if she lives alone in her enclosure? The mystery of Momo's pregnancy was made even more difficult to solve by the two barriers that separate her from the other gibbons. Protective of her baby, Momo wouldn't let the zookeepers get close enough to collect the necessary DNA samples. Finally, after years of attempts, the zookeepers were finally able to collect DNA samples from Momo's son and narrowed it down to four potential fathers living nearby. The evidence they obtained solved the mystery. The results were conclusive: Itoh, a 34-year-old gibbon, was the father.

The mystery of how the gibbons at Kujukushima Zoo & Botanical Garden managed to mate had zookeepers stumped until DNA testing revealed the truth. According to a report by CNN, it appears that the two primates had connected through a small, nine-millimeter perforated board that separates the male, Itoh, and the female, Momo when they rotate out of the exhibition area in the morning and afternoon. Mating is a process that gibbons take seriously. They are incredibly picky when it comes to choosing a partner, selecting based on appearance, social behavior and vocalizations. Itoh must have gone through quite a process to attract Momo's attention, which is why the staff was so shocked to learn what had happened.

Now that the full family picture has come into view, the zoo is slowly working on having Itoh join Momo and her son. It will take some time for them to get used to each other, but hopefully, they can soon live together as one family.

To ensure that there are no more surprise pregnancies, the staff has replaced the perforated board with a partition that has no openings. They are also monitoring the gibbons more closely and providing enriching activities to keep them entertained. While it is unfortunate that Momo and Itoh will no longer be able to mate, the staff is happy that the mystery of Momo's pregnancy has been solved and that the two will soon be reunited.