There are now only two females of the subspecies left in the world.
The world’s last male northern white rhino has died in Kenya, leaving only two females of its subspecies alive.
Ol Pejeta Conservancy said the rhino, named Sudan, was euthanised on Monday, aged 45, after being treated for “age-related complications” that had affected his muscles and bones, and given him extensive skin wounds.
“His condition worsened significantly in the last 24 hours; he was unable to stand up and was suffering a great deal,” the conservancy, where Sudan lived under armed guard to prevent poaching, explained.
Only two females of the subspecies now remain — Sudan's daughter Najin and Najin's daughter Fatu.
Sudan was transferred to the Ol Pejeta Conservancy in 2009 from the Dvur Kralove Zoo in the Czech Republic.
Ol Pejeta CEO Richard Vigne described Sudan as "an altogether lovely character" who was "incredibly approachable, very tolerant and patient of humans."
"It got to a point over the past two weeks where he was becoming almost completely recumbent. He was in obvious pain as a result of various infections and he was incredibly uncomfortable and had stopped eating so the best thing for us to do was to take the decision to relieve him of his suffering and to euthanise him," he told Euronews.
"He’s become a well known character on our conservancy... he will be sadly missed."
In 2017, conservationists put Sudan on dating app Tinder as "The Most Eligible Bachelor in the World", in hopes of raising enough money for a fertility treatment after attempts at getting him to mate naturally failed.
Conservationists now hope that Sudan, who was infertile for around five years before his death, can help still help to repopulate the species.
Ol Pejeta noted that a copy of Sudan’s genetic material was taken on the day of his death, providing hope for future efforts to bring the species back from the brink of extinction through in vitro fertilisation (IVF) techniques.
"It’s a really complex process — it's never ever been done in rhinos before. It now revolves around the two remaining females. They are the last single repository of eggs left on the planet for northern whites," said Vigne.
The process involves removing eggs from the two remaining females and fertilising them with Sudan's semen to create embryos, which will ultimately be put into surrogate southern white rhinos.
"So far they’ve been able to remove eggs but they have as yet not been able to successfully mature the embryos to the point that they can be frozen," he said.
"This is new technology. Obviously it's been practiced for many years in humans and other domestic species of livestock, such as cows and sheep and horses so it’s definitely doable... but doing it in them [rhinos] is fraught with difficulty."
Keeping the females alive
Vigne said the main challenges to saving the species were finding the money needed to develop the science, which they estimate will cost between $8 million and $9 million (€6.5-7.3 million), and keeping the two female rhinos alive.
"If they were to die right now, there is no way of removing their eggs and keeping their eggs alive... their eggs would die with them and that would mean that the species would become extinct," he explained.
The bigger picture
Vigne stressed that the decline of the northern white rhino is "a simple signal to what we as humans are doing to the planet and the impact we’re having on thousands of species."
Our current way of living "is not something that can continue if we as humans want to continue to live on this planet. That’s the message that should be taken home by people when they read about or hear about Sudan and his death.”
Rhinos across Africa first went into decline during colonial-era hunting and habitat loss caused by agriculture and urban development.
The population of northern white rhinos in Uganda, the Central African Republic, Sudan and Chad was decimated by poaching in the 1970s and 1980s.
Fighting in the Democratic Republic of the Congo killed off the last few dozen northern white rhinos by the early 2000s.
By 2008, the species was considered extinct in the wild, according to the World Wildlife Fund.
Vigne said he hoped Sudan's death would be seen as "a seminal moment for conservationists world wide.”