The world's only remaining male northern white rhino was killed by poachers in April in Kenya, the conservation group that cared for the last of his species said on Monday.
Thousands of people came to mourn the death of Sudan, a 45-year-old rhino whose deterioration had been captured in graphic video. There was some hope for the future of his lone female relative, and Sudan's daughter Najin.
Conservationists had named her Najin, Swahili for "Hope," after her birth in 2014, and the name has been used on conservation efforts to save her. But she had been pregnant again, and there was no telling whether her calf would be a boy or a girl.
Sudan's loss "brings home the fragility of life and how little time we have to ensure our natural world is protected," Tusk Trust chief executive officer Jean-Jacques Graisse said.
The loss is especially painful because the northern white rhino was hunted close to extinction in the late 19th and early 20th centuries because of their horn, which is used in Asian medicine.
Conservation groups began a captive breeding program in the hope that they might be able to protect a population and to save the animal from extinction.
A decision to euthanize Sudan was made by Tusk Trust veterinarians and the WildlifeDirect wildlife veterinary team. The team, who had cared for Sudan since his capture in March 2009, decided the best course of action was to humanely kill him.
In mid-April, he lost his appetite and appetite and could not even stand, according to Trust spokeswoman Sally Boxall.
"He'd been declining rapidly for several weeks," Boxall said. "We made the heartbreaking decision in the interests of his welfare to euthanize him to end his suffering."
Sudan was also suffering from age-related issues that could not be treated in a safe manner, the group said.
"Sudan's deterioration highlights the urgency of the rhino poaching crisis and the challenges we face," Tusk Trust CEO Graisse said in a statement.
Conservationists had been banking on Najin's pregnancy to ensure the species' survival. Kenya's ambassador to the United States said she had been reported "in good health."
"We must not give up now," said a tweet by the Kenya Wildlife Service.
Sudan was euthanized "so that Najin can be at liberty to breed," the Tusk Trust said, adding that the only northern white rhino is his daughter Najin, who was captured in the same area of Kenya in 2009 and taken to the Ol Pejeta Conservancy, near the capital of Nairobi, where she now lives with five other rhinos in an open-air sanctuary.
She has fathered two calves at the refuge and a second offspring that died in 2014 of pneumonia. The two surviving male calves live on the other side of the conservancy and are not believed to be related to her, the Tusk Trust said.
A decision on what to do with Najin, now believed to be 20, has not been made yet, the group said.
Before being moved to Ol Pejeta, Sudan had lived for several years at the Dvur Kralove Zoo in the Czech Republic, after being smuggled out of Sudan.
Poachers killed Sudan because his horn was worth more dead than alive, as it is made of keratin, the same material found in human fingernails. The horn is an accessory rather than a food source for the animal, and is believed to have no medical properties.
A number of conservation measures have been introduced to protect the animal, which is listed by the International Union for Conservation of Nature on its Red List of Threatened Species. A campaign to ban the sale of rhino horn in Asia has also been supported by celebrities including actor Leonardo DiCaprio.
The U.S. government responded to the news of Sudan's death with a promise to continue efforts to save endangered species.
"We join the world in mourning the loss of this remarkable animal, and send our heartfelt condolences to his dedicated caretakers at the Tusk Trust," said the U.S. ambassador to Kenya, Robert F. Godec. "This poignant moment underscores our commitment to ensure that one of the world's most endangered species will not be lost forever."
In March, conservationists said there were fewer than 45 white rhinos alive, although numbers have dwindled over the decades. There are between 5,000 and 10,000 rhinos left in the world.
The International Union for Conservation of Nature says the last two northern white rhinos were a female named Nola, who died in 2006 at the San Diego Zoo, and her son Sudan, who died in Kenya in March.
Sudan's death follows another loss of the species: The last two of northern white rhinos were put down at Ol Pejeta in May. Both rhinos had been in decline for years, suffering from skin infections and foot infections, and later infections from being immobilised during transport.
A few rhinos of the southern white rhino species survive in eastern Africa, and up to 20,000 southern white rhinos still roam parts of southern Africa. Their population has dropped dramatically in recent years as a result of poaching for their horns, which are seen as a cure for everything from hangovers to cancer.
Sudan was found wandering alone in the bush in March 2009 and was taken to Ol Pejeta after his condition deteriorated and he stopped eating. The Kenya Wildlife Service at the time said it was unclear whether he was a bull or a cow and described him as emaciated, with a skin disease that appeared to be an abscess.
A few years later, a female rhino from his pod was captured in the same area, and she was named Najin. She and a male rhino named Shama, the last two northern white rhinos, were moved to the Ol Pejeta Conservancy.
Najin
