Bibi’s baby will be the first Nile hippo calf the zoo has seen in over 75 years. Bibi and her male companion, 35-year-old Henry, had been breeding since the opening of the Hippo Cove exhibit in July 2016, the zoo said in the a news release.
Reproductive physiologists at the zoo expected Bibi to be… well, expecting. In anticipation of a baby Nile hippo, Dr. Jessye Wojtusik and the Center for Conservation & Research of Endangered Wildlife began performing ultrasounds on Bibi in August.
The team can now see the spine and beating heart of the baby, Wojtusik said in the release.
How do you give a hippo an ultrasound?
The hippo keeper team has used “positive reinforcement,” which includes using the 3,200-pound mother-to-be’s favorite foods to condition her to stand in a certain location.
“Hippos are generally known for being very difficult to train and many folks were skeptical that we would be able to pull this off,” Wojtusik said the release.
Africa head keeper Wendy Rice said two things work in their favor with Bibi; she’s been trained before at the Saint Louis Zoo and when in doubt, keepers just reach for the treats.
“Once she’s in position and holding steady, we keep the treats coming and Bibi is more than happy to cooperate. On a good day, she’ll hold her position for up to 15 minutes, giving us plenty of time to search for the baby,” Rice said in the release.
Rice also said Henry has been an “amazingly supportive and doting partner.”
The first-time mom’s official due date is sometime in March, and keepers said she will mostly likely deliver in an indoor pool.