The world's last male northern white rhino has died, the Kenyan conservancy taking care of it says, leaving only two of its subspecies alive in the world.
Ol Pejeta Conservancy in Kenya said in a statement the 45-year-old rhino was euthanised on Monday (local time) after his condition "worsened significantly" and he was no longer able to stand.
His muscles and bones had degenerated and his skin had extensive wounds. The veterinary team from the Dvůr Králové Zoo, Ol Pejeta and Kenya Wildlife Service made the decision to euthanize him.
The rhino had been part of an ambitious effort to save the subspecies from extinction with the help of the two surviving females.
"He was a great ambassador for his species and will be remembered for the work he did to raise awareness globally of the plight facing not only rhinos, but also the many thousands of other species facing extinction as a result of unsustainable human activity," the conservancy's CEO, Richard Vigne, said.
A copy of his genetic material was taken on the day of his death in the hope that future technology could potentially revive the species seemingly doomed for extinction.
Only two females of the northern white rhino species remain, Sudan's daughter Najin and Najin's daughter Fatu.
While there are thousands of southern white rhinos still roaming the plains of sub-Saharan Africa, decades of rampant poaching drastically cut northern white rhino numbers.
Sudan was something of a celebrity, attracting thousands of visitors.
In 2017, conservationists put Sudan on the dating app Tinder as "The Most Eligible Bachelor in the World", hoping to raise enough money for a $US9 million ($11.7 million) fertility treatment as all attempts at getting him to mate naturally had failed.
He had been born in Sudan, taken to a Czech zoo and then transferred to Kenya in 2009. Rangers caring for Sudan described him as gentle.
Sudan will be remembered for his unusually memorable life. In the 1970s, he escaped extinction of his kind in the wild when he was moved to Dvůr Králové Zoo. Throughout his existence, he significantly contributed to survival of his species as he sired two females. Additionally, his genetic material was collected yesterday and provides a hope for future attempts at reproduction of northern white rhinos through advanced cellular technologies. During his final years, Sudan came back to Africa and stole the heart of many with his dignity and strength.
“We on Ol Pejeta are all saddened by Sudan’s death. He was a great ambassador for his species and will be remembered for the work he did to raise awareness globally of the plight facing not only rhinos, but also the many thousands of other species facing extinction as a result of unsustainable human activity. One day, his demise will hopefully be seen as a seminal moment for conservationists world wide,” said Richard Vigne, Ol Pejeta’s CEO.
Unfortunately, Sudan’s death leaves just two female northern white rhinos on the planet; his daughter Najin and her daughter Fatu, who remain at Ol Pejeta. The only hope for the preservation of this subspecies now lies in developing in vitro fertilisation (IVF) techniques using eggs from the two remaining females, stored northern white rhino semen from males and surrogate southern white rhino females.