A Savanna Behind the Iron Curtain

In March 1975, Sudan and five other northern white rhinos were captured in what is now the country of South Sudan. After a six-month journey, they arrived at Dvur Kralove Zoo, then known as the East Bohemian Zoological Garden in the Soviet nation of Czechoslovakia.

At that time, it was a prominent destination for tourists as well as a zoological research station. The zoo’s longtime director, Josef Vágner, was obsessed with African animals. When he took over the zoo in 1965, he wrote to the ambassadors of Czechoslovakia and several African nations, hoping to obtain a visa to visit the continent. The only ambassador who replied was from Uganda, according to Stejskal, who has Vágner’s diaries. During the next two decades, Vágner would make eight expeditions to Africa and import more than 2,000 animals, mostly ungulates including zebras, giraffes, antelope, elephants — and rhinos.

“He had a dream that he would build something like a small Africa in the area where he lived,” Stejskal says. “For people behind the Iron Curtain, it was like a miracle. We could not travel. Even going to Poland or Russia was problematic. But now in this land of gray, you have this place where you have elephants, giraffes, unbelievable number of zebras, and other animals.”

By 1975, Dvur Kralove Zoo officials were breeding large numbers of animals. Vágner planned to build a big enough population to eventually return them to Africa. Even in the 1960s, their habitat was diminishing. In a 1967 diary entry from Uganda, Vágner argued that taking animals from Africa to European zoos was humane and justifiable as a means to protect them. As he saw it, “habitat for wild animals in Africa was diminishing, and soon they will be extirpated from large areas,” Stejskal wrote. The zoo’s efforts to save the white rhino are an extension of this legacy, he added. 

“We are convinced that if we have the techniques at our fingertips, we really should try to utilize it for the good of the northern white rhino,” he wrote.

Precious Sperm

After the journey back to Africa, Sudan and another male rhino attempted to mate with the few remaining females in 2011 and 2012. Caretakers watched and waited. A rhino’s gestation period is 16 months, so by 2014, it was clear there would be no baby. That fall, Suni died, at age 36. Crestfallen, Stejskal traveled to Ol Pejeta, and caretakers ran a suite of tests on Sudan, Najin and Fatu. Fatu showed pathological changes in her uterus that suggested she may have been pregnant and miscarried. Nijan’s reproductive organs were fine, but at 36 she is elderly for a rhino, and she has some problems with her hind legs that would make her unable to carry a 220-pound fetus.

The research team knew they were running out of options, and they had already started to prepare. Researchers at the Leibniz Institute for Zoo and Wildlife Research in Germany, as well as an animal reproductive technology lab called Avantea in Cremona, Italy, were working toward in vitro fertilization. If the researchers could harvest healthy egg cells from female rhinos, they could then inject sperm previously collected from Sudan and later frozen. The rhino embryo could then be implanted into a surrogate mother, a southern white rhinoceros, who would later give birth to a hybrid calf.

During IVF in humans, a woman’s hormone levels and egg development are carefully monitored with blood tests and ultrasounds, and egg retrieval and fertilization is precisely timed. But for a rhino, the effort is much more difficult.

“We cannot monitor the whole process, so we have to go sort of blind,” says Cesare Galli, a veterinarian and embryologist at Avantea. “We give it a little hormonal stimulation, but we find it is always unpredictable. Not every animal responds in the same way.”

What’s more, female white rhino ovaries are about 6.5 feet inside her body, so the animal must be under anesthesia for the procedure. Technicians spent two years refining their techniques, Galli says.





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