CINCINNATI, OH (WDTN) – The Cincinnati Zoo & Botanical Garden announced Monday that one of its Nile hippos, ‘Bibi,’ is pregnant.
The zoo said that its staff captured the first-ever ultrasound image of a Nile hippo last week, confirming that its 17-year-old hippo Bibi is pregnant.
Zoo staff, led by Dr. Jesse Wojtusik started performing weekly ultrasounds in August.
“In the early months, the uterus and developing fetus are located dorsally (closer to her spine). Once the fetus increases to a certain size it pushes lower into the abdomen so we are able to visualize it. We can now see the spine and beating heart,” said Wojtusik. “Ultrasound provides a more definitive diagnosis of pregnancy than hormone profiles, which are sometimes misleading, and allows fetal viability assessment.”
Wojtusik credits the hippo keeper team with making this milestone pregnancy diagnosis possible, saying that “Hippos are generally known for being very difficult to train and many folks were skeptical that we would be able to pull this off.”
The gestation period for this hippo species is eight months, so Bibi’s official due date is sometime in March. Baby proofing and birth planning have already begun. Unless temperatures are unseasonably warm, she will most likely deliver in her indoor pool. In the wild, female hippos leave the group a couple days before birth and return with the calf 10-14 days later.
The first residents of Hippo Cove received a breeding recommendation from the Association of Zoos and Aquariums (AZA) Species Survival Plan (SSP), the organization that monitors animal populations in Zoos. Henry has sired several calves, but Bibi will be a first-time mom. It’s been more than 75 years since the Cincinnati Zoo welcomed a Nile hippo calf.
Nile hippos, also known as river hippos or river horses, are vegetarians and can weigh as much as 4,000 pounds. Males are typically much larger than females. Although hippos spend much of their day in the water, they actually can’t swim at all. They float or walk along the bottom of the water.