Zoo Figures Out How Gibbon Who Lived Alone Gave Birth

It was a head-scratching birth. Momo, a 12-year-old white-handed gibbon, lived alone in a cage at a Japanese zoo—and delivered a shock when she delivered a baby in February 2021. As Vice reports, zookeepers at the Kujukushima Zoo and Botanical Garden in Nagasaki couldn't figure out how Momo could have mated with one of her male neighbors, since "two layers of barriers"—bars and chicken wire—separated them. Two years later, the zoo thinks it has figured out the mysterious birth, and it took a DNA test for it to get there.

That DNA testing—of hair and stool samples from Momo, her still-unnamed baby, and four possible fathers—revealed Momo somehow mated with Itoh, a 34-year-old agile gibbon who occupied an adjacent enclosure. As for the "how" in that somehow, the zoo has a theory: It tells CNN it believes the mating occurred via a 0.3-inch hole in a steel plate between their enclosures. As for why it took so long to solve the mystery, the zoo's superintendent tells Vice, "We couldn’t get close enough to collect samples—she was very protective of her child." The zoo hopes to eventually move Itoh into the same enclosure as Momo and her son. (More strange stuff stories.)