WHITE RHINO EXTINCTION AVOIDABLE THROUGH EMBRYO TRANSFER

A lot of animals I grew up with are disappearing today. They include the Massasauga Rattlesnake, the Gray Fox, the Sunfish, the Barn Swallow, the Redheaded Woodpecker, and even the simple Bumblebee.

It’s part of a larger, global trend toward vanishing species that scientists are calling the Sixth Mass Extinction. We’re experiencing a major decline in Earth’s biodiversity.

The causes of this so-called Anthropocene extinction are habitat destruction, climate change, pollution and resource extraction. These, of course, are all human activities.

People Used to Think Species Extinction Was Impossible

People used to think that species extinction was impossible. The disappearance of the Dodo and the near extinction of the American bison demonstrated that the possibility was all too real.

Naturalists started organizing conservation movements, and governments established the first nature preserves and national parks. The modern environmental movement gradually arose, but the global mass extinction is still accelerating.

One of the world’s most endangered species is Africa’s northern white rhino. There are only two northern white rhinos left on Earth, a mother named Najin and her daughter Fatu.

Dr. Thomas Hildebrandt: Pioneer of Assisted Reproduction

Dr. Thomas Hildebrandt studied veterinary medicine at Humboldt University in Berlin. He then earned a doctorate from Berlin’s Freie University and he’s been certified as a zoo, wildlife and game veterinarian for the past two decades.

Working with the international conservation consortium BioRescue, Dr. Hildebrandt has become one of the world’s pioneers of assisted reproduction in large mammals, like elephants, big cats, pandas and rhinos. This week, BioRescue announced the results of an experiment of which Dr. Hildebrandt was the project head.

The team achieved the first pregnancy in a rhinoceros from an embryo transfer. They produced a white rhino embryo using in vitro fertilization from collected egg and sperm cells.

Transferred Embryo Into Surrogate Mother

They transferred the embryo into a surrogate mother, a southern white rhino, at the Ol Pejeta Conservancy in Kenya on September 24, 2023. Seventy days later, the team was able to confirm a viable pregnancy involving a 6.4 cm male foetus.

These are southern white rhinos, while the virtually extinct species is the northern white rhino. Even so, this  pregnancy is the proof of concept the team needs to try to rescue the northern white rhino species.

The veterinarians drew the egg cells, or oocytes, from a rhino named Elenore. She’s a southern white rhinoceros at the Pairi Daiza Zoo in Belgium. 

In Vitro Fertilization at Avantea Laboratories

The biological father is Athos, a male southern white rhino from the Zoo Salzburg in Hellbrunn, Austria. The in vitro fertilization took place at the Avantea laboratories in Cremona, Italy.

The BioRescue staff transferred two embryos into Curra, the surrogate mother in Kenya. In vitro fertilization has become very common in domestic animals, like cattle, but it’s never been attempted in rhinos until now.

“The embryo transfer technique is well established for humans and for domesticated animals such as horses or cows, “ Dr. Hildebrandt explained.  “But for rhinos, it has been completely uncharted territory.”

Surrogate Mother Died of Infection

Sadly, when the BioRescue team went to conduct a pregnancy check on Curra in Kenya, they found she had died on November 25. Heavy rains had flooded her surrogate enclosure, releasing clostridial bacteria spores.

Curra had developed a fatal systemic infection. Suddenly, the BioRescue team became a crisis management team.

BioRescue promptly implemented protection measures for all other semi-captive rhinos, including Najin and Fatu, the last surviving northern white rhinos. They  vaccinated all the rhinos, set up a quarantine, and built new emergency enclosure fencing. 

Autopsy Revealed Viable, 70-Day-Old Foetus

The consolation for the team was that Curra’s autopsy also revealed she was carrying an otherwise viable, 70-day-old foetus. Further analysis of the foetus tissue confirmed that the pregnancy definitely came from the embryo transfer. 

“It is bitter that this milestone is confirmed under such tragic circumstances with the death of the surrogate Curra and her unborn calf,” Dr. Hildebrandt said. “But I am certain that this proof of concept is a turn of the tide for the survival of the northern white rhino and the health of Central-African ecosystems.”

Along with the only two living, female northern white rhinos, scientists have carefully preserved living cells from twelve other specimens using liquid nitrogen. Starting in 2019, BioRescue has produced and conserved 30 northern white rhino embryos in vitro in Berlin and Cremona.

And Another Thing…

Now the plan is to transfer these embryos into southern white rhino surrogate mothers. Having demonstrated that embryo transfers in rhinos are safe, effective and ethical, BioRescue is in a position to attempt the first pregnancy using the northern white rhino embryos over the next few months.

Projects like BioRescue’s embryo transfer are part of the transition humanity needs from the current Anthropocene era with its mass extinctions and natural resource exploitation. We need to move into a new era that many are coming to call the Ecozene, in which humanity learns to heal, and harmonize with, our planet’s delicate  ecosphere.

“We want the offspring to live together with Najin and Fatu for years to learn the social behaviour of its kind,” Dr. Hildebrandt concluded. “We are in a rush to bring a northern white rhino baby to the ground – with this proof of concept it can become a reality in two to three years.”

We always have more to learn if we dare to know.

Learn more:

Scientists have successfully created Northern white rhino embyros

World’s first successful embryo transfer in rhinos paves the way for saving white rhinos from extinction

The Sixth Extinction: An Unnatural History - A Review

Monarch Butterfly Added to Endangered Species List

Earth Species Project Talks to Animals Using AI