CINCINNATI – Fiona the hippo is going to be a big sister.

The Cincinnati Zoo and Botanical Garden announced Monday the news that Bibi, Fiona’s mother, is pregnant. This is Bibi’s second pregnancy.

A photo of the ultrasound performed on Bibi to confirm the pregnancy. (Photo courtesy of Cincinnati Zoo and Botanical Garden)

While excited, the Bibi's care team remains cautiously optimistic about the news.

Now 5, Fiona was born six weeks premature. She wouldn’t have survived without the intervention of her human caregivers.

“The hippo team is excited and also nervous,” said Eric Byrd, who manages the Cincinnati Zoo’s Africa team. “We are hoping for a full-term pregnancy and will be doing everything we can to support Bibi.”

Reproductive physiologists at the Zoo’s Center for Conservation and Research of Endangered Wildlife (CREW) are working with the hippo team and have started Bibi, 23, on hormone supplements. They will also perform regular ultrasounds to monitor the growth and health of the fetus.

The zoo didn’t mention how far along Bibi is into the pregnancy.

Hippos have a relatively long gestation period of around 240 days or eight months.

Zookeepers will probably separate the father, Tucker, from Bibi during the birth and for about two weeks after. In the wild, female hippos leave the group a few days before birth and return with the calf 10-14 days later, according to the zoo.

Tucker is new to Cincinnati. The 18-year-old arrived in Hippo Cove in September 2021. Fiona’s father, Henry, passed away in 2017. He was 36. Hippos can leave up to 50 years.

Tucker and Bibi had a breeding recommendation from the Association of Zoos and Aquariums (AZA) Species Survival Plan (SSP) Program, the group responsible for managing the health and genetic diversity of the hippo population in North American zoos.

Tucker and Bibi had an immediate connection, the zoo said. That’s what led to a sooner-than-expected pregnancy.

The zoo had Bibi on contraception at the time of her pregnancy. The dose that was previously effective for Bibi did not prevent pregnancy this time.

“We weren’t planning to welcome a baby this soon, but nature found a way and ignored our calendar,” said Christina Gorsuch, who leads animal care at the zoo.

The news of the pregnancy sparked some concern about the future of Cincinnati’s favorite hippo family.

But there is enough space in Hippo Cove for three adults and a calf, the zoo said.

In a playful social media campaign, the zoo dropped a few pregnancy hints. Thousands of their followers guessed everything from a baby frog to a baby elephant. The majority, however, guessed correctly that Bibi is pregnant, the zoo said in a release.

The Zoo plans to share updates on Bibi and baby preparations in the months leading up to the birth. 

The new hippo is just one of several new animals expected at the zoo this year. The Cincinnati Zoo will host its annual Zoo Babies showcase this May.